The Study of the Cosmic Gamma-Emission Nonstationary Fluxes Characteristics by the AVS-F Apparatus Data

  • Yu. D. Kotov
  • I. V. Arkhangelskaja
  • A. I. Arkhangelsky
  • S. N. Kuznetsov
  • A. S. Glyanenko
  • P. A. Kalmykov
  • D. B. Amandzholova
  • V. T. Samoylenko
  • V. N. Yurov
  • A. V. Pavlov
  • O. I. Chervyakova
  • I. V. Afonina
Chapter
Part of the Astrophysics and Space Science Library book series (ASSL, volume 400)

Abstract

The AVS-F apparatus (Russian abbreviation for Amplitude-Time Spectrometry of the Sun) is intended for the solar flares’ hard X-ray and gamma-ray emission characteristic studies and for the search and detection of the gamma-ray bursts (GRB). At present over 1,100 events with duration more than 2 s without any coordinate relations to Earth Radiation Belts and South Atlantic Anomaly were separated on the results of preliminary analysis of AVS-F experiment database.About 68 % of the identified events were associated with quasistationary equatorial precipitations-15-30 % count rate increases in the low-energy gamma-band of the AVS-F apparatus over its average value obtained by approximation of these parts with polynomials discovered on some equatorial segments in the ranges of geographic latitude of 25 up to +30. Several short events with duration of 1-16 ms associated with terrestrial gamma-ray flashes were registered during the experiment. These events were detected above the powerful thunderstorm formations.Solar flares with classes stronger than M1.0 according to the GOES classification were about 7 % of the detected events. Solar flares’ hard X-rays and γ-emission were mainly observed during the rise or maximum phases of the emission in the soft X-rays band according to the detectors on board the GOES series satellites data and duration of their registration is less than of the soft X-ray bands. According to the preliminary data analysis gamma-emission with energy over 10 MeV was registered during 12 % of the observed flares. The emission in the energy band E ¿ 100 keV was registered during over 60 faint solar flares (of B and C classes according to the GOES and from several ones γ-quanta with energy up to several tens of MeV were observed.Several spectral line complexes were observed in the spectra of some solar flares stronger than M1.0 in the low-energy gamma-range. Registered spectral features were corresponded to α α-lines, annihilation line, nuclear lines, and neutron capture line on1H (2.223 MeV). In the spectrum of the January 20, 2005 solar flare the feature in the range of 15-21 MeV was detected for the first time. It can be associated with lines of 15.11 MeV (12C +16O) or 20.58 MeV (from neutron radiative capture on3He), or with their combination. Also several e-dominant flares without any gamma-lines in energy spectra were identified. All detected faint solar flares were e-dominant according to the preliminary data analysis.Thin structure with characteristic timescale of 30-160 s was observed at 99 % significance level on some solar flares stronger than M1.0 temporal profiles in the low-energy gamma-band in the energy ranges corresponding to the identified spectral features or whole gamma-band energy boundaries. According to the results of the preliminary analysis during the flare of January 20, 2005, thin structure with timescale from 7 ms to 35 ms was detected at 99 % confidence level in the energy range of 0.1-20 MeV. Some thin structure with characteristic timescale 50-110 s was observed on temporal profiles of several faint events.About 3 % of the identified events were gamma-ray bursts. During some bursts high-energy gamma-emission was observed, for example Emax = 147 ± 3 MeV for GRB050525.

1

The AVS-F apparatus (Russian abbreviation for Amplitude-Time Spectrometry of the Sun) [7, 8] is intended for the solar flares hard X-ray and gamma-ray emission characteristics studies and for the search and detection of the gamma-ray bursts (GRB). The experiment was carried out in the framework of the international program CORONAS(Complex ORbital Near-Earth Observations of the Active Sun) [56] on board the specialized automatic station CORONAS-F [74, 75, 76] successfully launched on July 31, 2001. The satellite operated until December 6, 2005.

The AVS-F apparatus [8, 44] provided information for the analysis of the following problems:
  • definition of the solar flares gamma-emission variability minimum time;

  • study of charged particles’ acceleration dynamics during the flare by the energy spectra sequence analysis;

  • studies of the particles acceleration and propagation mechanism during the flare basing on gamma lines from excited nuclei, neutron capture and positron annihilation analysis;

  • search for temporal correlations with fine time resolution between solar flares emission in gamma-ray band and other energy ranges;

  • analysis of the solar flares X-ray precursors behavior and their energy spectra;

  • non-thermal emission lower boundary refinement;

  • neutron fluxes measuring by analysis of a sequential sets of two-dimensional distributions of the relation between the slow light output component to total light output ratio and total energy deposition in the CsI(Tl) scintillation detector;

  • background conditions analysis.

AVS-F Apparatus Short Description

The AVS-F apparatus continued an experiment AVS conducted on board the satellite CORONAS-I [42, 71]. As well as for the AVS experiment of the CORONAS-I project, the apparatus AVS-F was intended for processing of the information from the SONG-D detector of the SCR complex, developed by SINP MSU (see description in the chapter “Scientific Set of Instruments “Solar Cosmic Rays””) and XSS-1 detector also named RPS-1 detector in Russian publications (see description in the chapters “RPS-1 Experiment”).

The SONG-D detector (Solar Neutrons and Gamma-quanta) is a scintillation detector on the basis of CsI(Tl) crystal with a diameter of 200 mm and a height of 100 mm surrounded with plastic anticoincidence detector [83]. Using X-ray semiconductor spectrometer XSS-1 [90, 91, 105] on the basis of CdTe semiconductor with dimensions of 4. 9 × 4. 9 mm and thickness of 2.5 mm was conceptually new compared with the AVS experiment on board the CORONAS-I satellite. CdTe semiconductor detector does not need deep cooling (down to ≈ −30  ​​C) in order to provide sufficiently high energy resolution. It provides high registration efficiency and radiation resistance, along with other advantages of the semiconductor detectors, and are operated at low power supply voltage. The XSS-1 was developed by MEPhI and IKI RAS in cooperation. The results of detailed data analysis for the XSS-1 detector are presented in the chapter “RPS–1 Experiment.”

The AVS-F apparatus was the system of electronics for on board data acquisition from two detectors: SONG-D in the low-energy (0.1–10 MeV) and high-energy (2–80 MeV) bands of gamma-emission, and XSS-1 in the energy range of 3–30 keV of X-rays. The AVS-F apparatus operational ranges boundaries are presented according to the data of preflight calibration (about the changes of the operation ranges during the experiment see the section “In-Flight Calibration in γ-Bands”).

The AVS-F apparatus had two operation modes: background mode for the analysis of radiation flux and the search for event of “burst” type, and burst recording mode switched in after such an event was identified (for the detailed description see p. 181).

The AVS apparatus was completely modified in order to provide complex processing of the data from two detectors simultaneously in three energy ranges [42, 71], and the part of the device providing acquisition of spectrometry information [8] was changed most strongly. The information from the low-energy channels (the XSS-1 and SONG-D detectors) was processed by analog-to-digital converters with 512 primary channels, and the data in the high-energy ranges and separation of the neutrons and gamma-quanta using the ratio of light output components in CsI(Tl) (from the SONG-D)—by specific ADC converters with 256 primary channels. In order to decrease the amount of the transmitted information ADC channels were compressed in a quasi-logarithmic algorithm. There were 114 channels in the low-energy range (32 for the XSS-1 and 82 for the SONG-D detectors) and 64 channels for the background mode and 114 channels for the burst mode for the SONG-D detector in the high-energy range. The more detailed description of the information obtained from the apparatus AVS-F is presented in page 178.

The discrimination between gamma-emission and neutron events was performed using the selection of events by the pulse shape analysis in the scintillation detector, based on the dependence of the ratio of intensities of light-output components in CsI(Tl) scintillator with different decay times to the average ionization density produced by charged particles in the detector material. Scintillation flare in CsI(Tl) consists of two basic components, and there is relation between the ratio of the slow component intensity Lsl to the fast one Lf and the mean specific ionization of the detected particle (measured in units MeV/g/cm2) [41, 46]:
$$\displaystyle\begin{array}{rcl} L_{\text{sl}}/L_{\text{f}} = (0.96 \pm 0.03) - (0.11 \pm 0.01)\ln (\mathit{dE}/\mathit{dx}),& &{}\end{array}$$
(1)
where dEdx—the mean specific ionization.

The light flare energy is proportional to the total charge of the RC-chains capacitors, which compose the output cascade of the front-end electronics. The charge of the separate RC-chain characterizes the fast (τf ≈ 0. 7 mks) or slow (τsl ≈ 7 mks) component of the CsI(Tl) scintillator light output. The method used in the AVS-F apparatus is based on the integration of the signal from the photomultiplier of the SONG-D in two different time intervals. The first interval corresponds to the period of the total charge \(Q_{\text{tot}} = Q_{\text{f}} + Q_{\text{sl}}\) collection lasts from the pulse leading edge till 10 mks, and the second time interval was the time during which the slow fluorescence component was collected, and lasts from 1 mks after the leading edge of the pulse till 10 mks. For each detected event the values Qtot and \(Q_{\text{sl}}/Q_{\text{tot}}\) were converted by 8-bit analog-to-digital converters and transmitted to the micro-controller KS-MP [30].

The data obtained by the AVS-F apparatus was transmitted by means of two telemetric systems: RadioTelemetry System RTS-9 and the system of information acquisition SSNI (see the chapter “On-Board and Ground-Based Complexes for Operating the Science Payload of the CORONAS-F Space Mission”).

System control was accomplished by ten commands [7]. The telemetry system had following features:
  • analogous channels—4;

  • digital channels—9;

  • quota SSNI—8 MB/day.

The AVS-F apparatus provided [8, 44]:
  1. 1.
    acquisition and outputting of the following information to the radiotelemetry system (sample frame for RTS-9 is 2.5 s):
    • counts rate in four energy ranges of 3–5 keV, 5–10 keV, 10–20 keV, and 3–30 keV [105] from the XSS-1 detector;

    • total counts rate from the SONG-D detector in the low-energy and high-energy gamma-ranges;

    • total counts rate for the channel corresponding to the two-dimensional distributions of the relation between the ratio of the slow fluorescence component to the total light output and total energy release for the SONG-D detector;

    • total counts rate of the anticoincidence detectors of the SONG-D detector;

     
  2. 2.
    acquisition and outputting of the following information to the scientific telemetry:
    • in the background mode:

    • background energy spectra in the X-ray band (from the XSS-1 detector) and low-energy gamma-emission (from the SONG-D detector) (the integration time is 16 s, number of channels of amplitude analysis after compression—114, including 32 channels of spectra from the XSS-1 detector, 82 channels of spectra from the SONG-D detector);

    • a set of two-dimensional distributions of the relation between the ratio of the slow fluorescence component to the total light output and total energy release for the SONG-D detector, which are used for the investigation of the neutron flux (matrix size is 64 × 64, integration time is 128 s);

    • test arrays containing information about the available operation modes of the apparatus and the results of apparatus self-testing;

    • in the burst mode:

    • energy spectra in X-ray (from the XSS-1 detector) and low-energy gamma-ranges (from the SONG-D detector) (the integration time is 1 s, number of channels of the amplitude analysis after compression—114, including 32 channels of spectra from the XSS-1 detector, 82 channels of spectra from the SONG-D detector);

    • burst event temporal profile in the low-energy gamma-range with 1 ms time resolution (4,096 channels of temporal profile);

    • energy spectra in the high-energy gamma-range (from the SONG-D detector) (integration time is 4 s, number of channels of amplitude analysis after compression—114);

     
  3. 3.

    generation of a signal “burst” during the operation in the background mode in the case of the gamma-emission flux intensity sharp increase with specific time of 8–16 ms on the value more than 5 σ and switching to the burst operational mode basing on the analysis of this information.

     

Users receive the description of the transmitted information formats along with the requested data. The information for the determination of the spacecraft position at the orbit according to the NORAD data (http://www.celestrak.com/NORAD/documentation/tle-fmt.asp) is also provided.

The AVS-F apparatus was developed basing on the block system of electronics [7, 8, 90] and included electronics crate with power supplies and a set of functional blocks [30]. Functional diagram of the experiment AVS-F is presented in Fig. 1.

Fig. 1

The AVS-F experiment functional diagram. From [30]

Each block of electronics system is the plate with dimensions of 160 × 180 mm with the front panel 20 mm width (or multiple) intended for fitting of connectors and block’s mounting in the crate.

Overall dimensions of the apparatus are 275 × 400 × 190 mm, mass is ∼ 12 kg. For the regular operation of the apparatus DC supply \(27_{-3}^{+7}\) V was used. Power consumption did not exceed 22 W.

KS-MP block was a system’s controller and was intended for the control, acquisition, and processing of the information, and for receiving of the digitized time label from the specific telemetry system SSNI and for data transfer to SSNI [30, 63]. Information was output to SSNI which serviced scientific apparatus according to the requests of electronic systems of the experiments. Data exchange was performed by the arrays of 960 bit frames through the synchronous sequence channel. Besides, the apparatus received 32-digit time label with the value of the lower order bit of 1/1024 s from SSNI. Microprocessor controller KS-MP provided acquisition, accumulation, primary processing of the information, generation of output data arrays, on board time referencing of the information, and data output to the SSNI system.

ADC-2N block was the part of modular electronic system intended for operation with CsI(Tl) detector. ADC-2N provided separation of the signals obtained from the detector in order to get information on the neutron flux (n) and gamma-emission flux (γ) by pulse shape analysis at the output of the SONG-D detector.

The objective of the ADC-2N included:
  • outputting of counting impulses corresponding to the total number of the events (n +γ) and to the number of the events satisfying selection criteria according to the ratio \(Q_{\text{sl}}/Q_{\text{tot}}\) (neutrons);

  • outputting of the information (8 bit) on the status of full charge integrator and ratio of the charge corresponding to the slow light output component to the total charge to the modular electronic system data bus;

  • identifying of signal overlapping and resetting in this case;

  • exchange of service signals with modular electronic system in order to manage ADC-2N operation;

  • resetting of process cycle according to the signal of the charged particle passing.

ADC-2M block was the part of modular electronic system intended for operation with SONG-D and XSS-1 detectors. Charge integration intervals for two different channels were selected individually and amounted to 7–10 mks to provide charge collecting from the detectors (for the SONG-D detector ∼ 10 mks; for the XSS-1 detector 7–8 mks). The objective of the ADC-2M included:
  • outputting of the impulses corresponding to the total number of the events on each of two channels of ADC-2M in the case if there is no restricting signal from the anticoincidence shield of the SONG-D detector. Integration times for charge congregating were selected for each detectors and were 7–10 mks for optimal charge congregating from both detectors. (The main part both slow and total light output components in the CsI(Tl) crystal had de-excitation time ∼ 10 mks; the integration time for the XSS-1 was 7–8 mks);

  • outputting the modular electronic system the information (8 bit) corresponding to energy deposition in the XSS-1 and the SONG-D detectors;

  • identifying of signal overlapping and resetting in this case;

  • exchange of service signals to manage the ADC-2M operation;

  • resetting of process cycle according to the signal of the charged particle passing through the detector;

The MD-M block was intended for the operation with the XSS-1 detector. The objective of the MD-M was to provide a signal on entry of photons with energy in specified range (one of the following four ranges: 3–5 keV, 5–10 keV, 10–20 keV, and 3–30 keV) into the detector’s volume. The data outputted to the block of intensimeters (BPN-4) for the following output to the RTS telemetry.

The BUA-AVS block included providing of different operation modes for the conducted devices according to the mode settings commands and using information from other experiments. According to the results of analysis of a set of starting and restricting commands coming to the BUA-AVS from other parts of the CORONAS-F complexes operated with the AVS-F apparatus (HELICON, IRIS, SONG, “Light/Shadow” sensors), individual signal “Burst” was produced in order to set the proper registration modes for the AVS-F apparatus. Also the signals managing the operation of the secondary power supplies of the AVS-F apparatus and control analogous signals from the secondary power supplies block to the service telemetry RTS were transferred through the BUA-AVS. Basing on the status of “switch on/ switch off” contacts of the secondary power supplies block, a set of control digital marks was formed in order to transfer them to the service telemetry system RTS.

The BNP-4 block was intended for the obtaining information on the flux of the input signals in the frequency bands up to 2 MHz, transformation of the measurements results into digital code and its outputting to the telemetry system through galvanic decoupler. The BNP-4 consisted of four identic measuring channels; each of them allowed to record the temporal profile of the input signals in the range of 0–15 V.

The BRV-3 block was intended for the writing of temporal profiles of gamma-emission with high time resolution. It was based on data storage of 4096 × 8 digits capacity.

Data acquisition interval was specified by the external fixed reference frequency.

The BVV-3 block was intended for identification of non-stationary events. Its operation principle was based on averaging of the background value for 128 collection intervals composing the cycle of the background collection, and using of the previous background average value as reference for the following collection cycle. Current value exceeding the reference value for a specified value (in this case—for 6 standard deviations) during one of the collection intervals was a mark of the event. In order to set an interval of collection the fixed reference frequency was used. Basic duration of one interval was 1 ms.

AVS-F Apparatus Background Model in the γ-Bands

Detector background depends on various factors including satellite mass and configuration, orbit parameters, detector material, detector location on board satellite, and solar activity level. Effect of all these factors results to specific background value for each experiment. Background of gamma-detectors on board the spacecrafts at low near-Earth orbits are defined by the following components [45, 49, 54, 62]:
  1. (a)

    cosmic diffuse gamma-rays;

     
  2. (b)

    atmospheric gamma-rays;

     
  3. (c)

    local gamma-rays and neutrons background produced via the direct interactions of cosmic rays and the materials of detector and spacecraft;

     
  4. (d)

    γ-rays from decay of neutral pions produced via cosmic rays and atmosphere nuclei interactions;

     
  5. (e)

    non-stationary events and electron precipitations;

     
  6. (f)

    decay of nuclides produced by interactions of cosmic rays and magnetosphere trapped particles with the materials of the detector and satellite;

     
  7. (g)

    discrete cosmic sources emission;

     
  8. (h)

    bremsstrahlung of electrons and positrons accelerated in astrophysical objects or produced due decays of other leptons or charged mesons be generated via interactions of accelerated in astrophysical objects ions and nucleons.

     

Various background components relative contribution depends on detector composition, satellite mass, and construction and differs essentially for different energy bands. In general it is a function of time and spacecraft position on its orbit [5, 17, 49]. The (a) and (g) components do not depend on the position of the satellite in the Earth’s magnetic field, while the other components contribution is specified by the value of cosmic rays flux, geomagnetic cutoff rigidity ((b)–(e) components), total dose accumulated during the satellite passing the regions of trapped radiation, and time interval duration from the moment of the trapped radiation regions passing till the moment of measurements ((f) component).

There are no requirements to construct detailed physical models of the above-mentioned background components for events identifying and analyzing of their features. It is more convenient to consider background model as a sum of empirical relationships approximating background counts rate temporal variations in each channel. For the experiments on board satellites with orbit inclination up to 40 background counts rate temporal variations usually were approximated by periodic functions constructed during several sequential orbits for each spectral channel; but infrequent South-Atlantic Anomaly (SAA) region passages were taken into account by the activation analysis [62, 97].

For satellites with orbit inclination over 70 (inclination of the CORONAS-F orbit was 82.5) the events in gamma-bands could be identified only in equatorial and polar-caps regions; therefore, background model rational should constructed only for these orbit parts. The detector counts rate background estimations were made due averaged counts rate values for several neighbour orbit parts with similar geomagnetic coordinates [17].

Fig. 2

Typical example of latitudinal profile of the AVS-F counts rate in the low-energy and high-energy γ-bands

Typical dependance of the summarized AVS-F counts rate on geomagnetic latitude in the low- and high-energy gamma-bands is presented in Fig. 2. There are well-defined Earth radiation belts, polar caps, and SAA regions (1, 2, and 3 correspondingly) in the high-energy and low-energy bands. Also the areas of precipitated from the external Earth radiation belt electrons bremsstrahlung registration in the low-energy γ-band were identified (4). The equatorial regions (5) were more interest for study because of the most favorable conditions for the burst events (solar flares and gamma-ray bursts) registration and analysis.

In the low-energy gamma-band of the AVS-F apparatus only gamma-rays were registered including bremsstrahlung of charged particles in structural materials (charged particles could be detected in this band were screened by anticoincidence shield). AVS-F apparatus background for different spectral channels in the low-energy gamma-band was analyzed in details in [5, 17]. It has shown that background count rate temporal (latitudinal) profile for each of the 82 channels approximated by a fourth-or fifth-degree polynomials at the satellite orbit equatorial segments, and by parabolic curve, linear function or constant at the polar regions (see Fig. 3).

Fig. 3

Typical latitudinal profiles of the AVS-F counts rate and their approximation in the low-energy (a) and high-energy (b) γ-bands. Profiles on the equatorial parts of the CORONAS-F orbit are approximated by fourth-degree polynomials (orange curves), on the polar parts by linear functions (red lines). From [5]

Such type background count rate profile approximation was used for solar flares spectra study and γ-lines identification. For instance, seven spectral lines complexes were separated by AVS-F data in the low-energy gamma-band at the October 29, 2003 solar flare spectrum using the above-mentioned method background subtraction [5, 17]. This event lasts during time interval 20:38–20:55 UT according to the data of the detectors on board the GOES-12 satellite. Its spectrum with and without background substraction and background spectrum is presented in Fig. 4. Four strong lines complexes were identified in the background spectrum and seven typical for solar flares γ-lines complexes were separated in this flare spectrum after background substraction.

Fig. 4

Energy spectrum with and without background subtraction and background spectrum for the solar flare of January 29, 2003. Specific spectral features are given by gray arrows at the background spectrum and by black ones at the flare spectrum with background subtraction. From [9]

Besides gamma-quanta, neutrons were detected via the secondary charged non-relativistic particles (isotopes of hydrogen and helium) in AVS-F high-energy band. Also relativistic protons were registered via ionization losses in this band due to limited efficiency of aniticoincidence shield.

As it was noted in the section “AVS-F Apparatus Short Description,” ratios of the slow and the total light output components in the CsI(Tl) scintillator differ for the particles with different specific ionization, therefore their detection corresponds to different areas at two-dimensional distributions of the ratio of the slow light output component to the total one related to the total energy deposition in the SONG-D detector. Examples of the summarized background two-dimensional distributions of the dependence of the ratio of the slow light output component to the total one from the total energy deposition in the SONG-D detector according to the data of the AVS-F apparatus in the equatorial and northern polar CORONAS-F orbit regions for undisturbed magnetosphere (Kp < 4) without burst events are presented in Fig. 5.

Fig. 5

Summarized background two-dimensional distributions of the ratio of the slow light output component to the total light output dependence on the total energy deposition in the SONG-D detector according to the AVS-F apparatus data in the equatorial and polar regions of the CORONAS-F orbit at quiescent magnetosphere (Kp < 4)

The data correspond to 296 orbits (N 19263–19559) in January 2005, total accumulation time was 69056.81 s (over 19 h) for the equatorial regions (\(-3{0}^{\circ } <\phi <+3{0}^{\circ }\), except the SAA region), and 24750.30 s (over 6 h) for the North polar regions (\(+8{3}^{\circ }>\phi> +6{5}^{\circ }\)). The areas corresponding to registration of the secondary particles from neutron interactions (including non-relativistic protons and α-particles), gamma-quanta, and relativistic protons are shown.

Detailed analysis of two-dimensional distributions of the ratio of the slow light output component to the total light output dependence on the total energy deposition in the SONG-D detector allowed to study in the high-energy range the behavior of the counts rate dependence on geomagnetic latitude separately for non-relativistic protons, α-particles, relativistic protons, and gamma-quanta [69].

In the high-energy range of the AVS-F apparatus the latitudinal profile of the background counts rate in the areas with specific ionization corresponding to gamma-quanta on two-dimensional distributions of the ratio of the slow light output component to the total light output dependence on the total energy deposition in the CsI(Tl) detector can be described by the forth- or fifth-degree polynomials at the equatorial orbit segments and by linear functions or constants at the polar ones analogous to the low-energy band (see Fig. 3b).

Latitudinal profiles for the areas corresponding to non-relativistic protons and α-particles can be approximated with the forth-degree polynomials in the equatorial region of the CORONAS-F satellite. One and the same polynomial (with normalization coefficient which takes into account difference of the counts rate in the analyzed regions) can be used for approximation of both profiles for non-relativistic protons and α-particles at the significance levels \(R_{p_{\mathrm{nonrel}}\mathrm{AVS-F}} = 0.99\) and \(R_{\alpha \mathrm{AVS-F}} = 0.85\), correspondingly. An example of such approximation for summarized latitudinal profiles normalized to the number of channels for Kp = 2 is presented in Fig. 6. Therefore the latitudinal profiles in the areas corresponding to non-relativistic protons and α-particles were in a good agreement, as it must be for the secondary particles registration.

Fig. 6

Summarized latitudinal profile of non-relativistic protons background counts rate normalized to the number of channels (black histogram) and summarized latitudinal profile of α-particles background counts rate normalized to the average counts rate of non-relativistic protons (gray histogram) according to the data of AVS-F apparatus at the equatorial parts of the CORONAS-F satellite’s trajectory (orbits 19263–19559 for January 2005) at Kp = 2. Black curve shows fourth-degree polynomial approximation of these profiles

For relativistic protons in the equatorial region of the CORONAS-F satellite orbit the dependance of the summarized counts rate from the latitude according to the data of January 2005 normalized to the number of channels is presented in Fig.7a. It can be approximated with the forth-degree polynomial at the level of significance of R = 0. 98—thick grey curve.

Fig. 7

The relativistic protons counts rate dependence on geomagnetic latitude in the equatorial region by data of AVS-F (a) and AMS (b). AVS-F data were normalized to the number of channels. From [69]

For relativistic protons area identification confirmation at two-dimensional distributions of the ratio of the slow light output component to the total light output dependence on the total energy deposition in the CsI(Tl) detector the AVS-F data were compared with the cosmic protons flux latitudinal profiles obtained by the AMS experiment [1, 2] on board the “Discovery” spacecraft in 1998. The profiles were observed at the same altitudes (360–380 km) as for the CORONAS-F satellite in January 2005. Latitudinal distribution of protons according to the data of the AMS experiment is presented in Fig. 7b. It also can be approximated with the forth-degree polynomial [69] at R = 0. 99. The data of the AVS-F apparatus corresponding to registration of relativistic protons (at Kp = 2) after renormalization taking into account difference of the response functions of the AVS-F and AMS detectors were approximated with the polynomial of the same degree with the same (in statistical errors) coefficients at the level of significance of \(R_{p_{\mathrm{rel}}\mathrm{AVS-F}/p_{\mathrm{rel}}\mathrm{AMS}} = 0.89\) [69] (thin black curve in Fig. 7a). Moreover latitudinal profile corresponding to the relativistic protons area doesn’t agree with the profiles corresponding to the areas of non-relativistic protons and gamma-quanta (black dotted curve and thin gray curve correspondingly in Fig. 7a): the level of significance of the approximation with conforming polynomials are \(R_{p_{\mathrm{rel}}\mathrm{AVS-F}/p_{\mathrm{nonrel}}\mathrm{AVS-F}} = 0.64\) and \(R_{p_{\mathrm{rel}}\mathrm{AVS-F}/\gamma \mathrm{AVS-F}} = 0.56\) only.

So, it is possible to identify areas corresponding to registration of secondary particles from interactions of neutrons (including non-relativistic protons and α-particles), gamma-quanta, and relativistic protons at two-dimensional distributions of the ratio of the slow light output component to the total light output dependence on the total energy deposition in the SONG-D detector; latitudinal profiles for the different types particles also differ due to the features of their origin and movement in the Earth’s magnetosphere.

In-Flight Calibration in γ-Bands

As it was noted in the section “AVS-F Apparatus Background Model in the γ-Bands,” background counts rate of the AVS-F apparatus in all energy ranges change essentially with time (depending on the spacecraft location in the orbit). During the movement of the satellite along the orbit in the Earth’s magnetic field charged particles fluxes significantly varied. Satellite was periodically exposed to intensive fluxes of charged particles activated both detectors and structural materials of the spacecraft, and these effects led to changes of the AVS-F apparatus counts rate too.

Changes of the dependance of the observed energy from the number of the channel of the registering instrument during its total operation period resulted due to ageing of the detecting elements and electronics. It should be taken into account during database treatment both for the low- and high-energy gamma-bands of the AVS-F apparatus due regular calibrations.

For apparatus calibration (in this case for determination registered particle energy dependance from the number of the analog–digital converter channel), it was necessary to separate characteristic lines with specified energy from the obtained background energy spectra. Average AVS-F apparatus counts rates at the parts of the orbit outside the radiation belts and SAA were ∼ 1, 000 counts/s in the low-energy gamma-band [72] and approximately ten times lower in the high-energy band [73]. Therefore it was necessary to accumulate spectrum during several hours at least to provide the reliable spectral lines identification. Orbit period of the CORONAS-F satellite was 90 min, so the accumulation time was not more than 20 min for one equatorial orbit part and not more than 15 min for one polar cap orbit region. The polar cap parts were selected from the shadowless orbit segments in the north polar cap in the latitudes range from + 65 up to + 82. 5, and equatorial ones from the shadowless orbit segments in the latitudes range from − 30 to + 30; the SAA region and the parts of the orbit in 3 h before and after its passing were excluded from the analysis. Therefore, it was necessary to summarize sufficiently great amount of equatorial or polar spectra to obtain calibration spectrum with accumulation time of several hours.

The primary calibration spectrum was resulted from summarizing 765 parts of the orbit near the equator during the initial period of the apparatus operation and its accumulation time was approximately 80 h. Typical example of the calibration spectrum is presented in Fig. 8a. Spectrum shape was specified by the bremsstrahlung of the electrons (with power spectrum) passed through the detector and the spacecraft elements structural materials, Compton scattering, and (or) pair production during registration of the background gamma-emission. It also included positron line of 0.511 MeB and background lines characteristic for this apparatus formed via the protons and neutrons interactions with the material of the detector and satellite construction. Just these lines were used for calibration. For the real channel number definition it was necessary to subtract the base (power-law at a first approximation) from the spectrum corresponding to background line with specified energy, or to multiply the spectrum on the power-law function, and in this case the lines basic for the calibration will be distinctly identified.2 The spectrum tends to the shape presented in Fig. 8b.

Fig. 8

Typical example of the summarized calibration spectra: (a) spectrum in the equatorial region with total integration time over 80 h, (b) the same spectrum, as in (a), multiplied by the squared number of the channel for more demonstrable lines identification. From [28]

There were 11 background lines separated in the calibration spectrum [9, 27, 72]. Their energies are presented in Table 1.

Table 1

Parameters of the background lines [55, 89, 92, 93]

E, MeV

Basic nuclides

 

0.38

I126, I128, Cs127, Cs129, Sn113, Xe127

 

0.5

\({e}^{+}\,{e}^{-}\), Na24m, Te121, Cs132, Sb115, I121, Cs128, Cs129,

 
 

Co55, In111m, Cs128, I126, I128

 

0.7

Cs132, I124, I126, Mn52, In110, Te119, Te117

 

1.46

K40, Na24, Mn52m, Mn52, Ni57, Mg24, Co55

 

1.8

Al28, Te119, Te117, I124, Na24, Mg26, Si28

 

2.2

n capture, Al27, Na24, Te117, Sb116, Ni57

 

2.6

Tl208, Al27, Na24

 

4.4

12, C 13, Na24, Si29

 

5.0

13, Si29, O16

 

6.0

O16, Fe57, Si28

 

7.6

Fe57, O16, Si29, Al28

 
Cesium, iodine, and thallium were composed in the scintillation detector crystal, aluminium was consisted in the structural materials of the apparatus and the spacecraft; iron was contained in the satellite orientation system; carbon and hydrogen were composed in the plastic anticoincidence shield; potassium, oxygen, silicon, nickel, and magnesium were contained in photomultipliers. The other isotopes from Table 1 were also products of interaction of cosmic rays with materials of the detector and the spacecraft. Relation between the energy E of the detected particle and the number of channel N in the low-energy gamma-band of the AVS-F apparatus was described by the following linear function at the 0.997 significance level:
$$\displaystyle{ E_{\text{low}\gamma }(\mathrm{MeV}) = (0.05 \pm 0.02) + N \times (0.0219 \pm 0.0002). }$$
(3)

Such significance level allows to use less number of lines for the subsequent calibration procedures.

Then we have studied the time-dependent changes of the calibration function using summarized monthly equatorial calibration spectra. Four background lines with average energies of 0.38 MeV, 0.5 MeV, 0.7 MeV, and 1.46 MeV were separated in each summarized spectrum and we used these lines as the base for calibration. Time dependance of calibration function is presented in Fig. 9.

Fig. 9

The evaluation of the AVS-F apparatus calibration with time. From [28]

The obtained curves were approximated with linear function:
$$\displaystyle{ E = A + B \times N, }$$
(4)
The results of data analysis have shown that approximation coefficients time dependences were the following: [6, 13, 28]:
$$\displaystyle\begin{array}{rcl} A& =& (2.1 \pm 0,9) \times 1{0}^{-2} + t_{ 1} \times (9.7 \pm 0.3) \times 1{0}^{-3} - \\ & &-t_{2} \times (3.3 \pm 0.9) \times 1{0}^{-4} + t_{ 3} \times (3.3 \pm 0.3) \times 1{0}^{-6};{}\end{array}$$
(5)
$$\displaystyle\begin{array}{rcl} B& =& (2.12 \pm 0.05) \times 1{0}^{-2} + t_{ 1} \times (7.5 \pm 1.1) \times 1{0}^{-4} - \\ & &-t_{2} \times (2.4 \pm 0.6) \times 1{0}^{-5} + t_{ 3} \times (3.8 \pm 0.9) \times 1{0}^{-7}.{}\end{array}$$
(6)

During 1 month the AVS-F apparatus energy threshold and conversion coefficient in the low energy gamma-band were changed for ∼ 1 % and ∼ 1. 8 % correspondingly, dynamical range changed from \((0.041 \pm 0.007 \div 10.9 \pm 0.1)\ MeV\) according to the August 2001 data up to \((0.11 \pm 0.01 \div 19.9 \pm 0.4)\ MeV\) according to the data of January 2005 [6]. Such change of the calibration characteristics of the AVS-F apparatus in the low-energy γ-band could be associated both with the detecting element (CsI(Tl) crystal) aging, degradation of optic contact between the crystal and the photomultiplier and the changes of the electronics parameters of the spectrometric tract [13].

As it was noted, ten activation lines were separated for the background spectra of the AVS-F apparatus in the low-energy gamma-band. Six lines are also detected in the high-energy band, but it is impossible to separate them in this band because the channels width in the area of the lines detection is ∼ 1 MeV. Therefore well-known envelope curve with a center at 7.62 MeV [101] is used. Moreover the characteristic feature of decay of the neutral pions produced by nuclear reactions of the cosmic rays’ protons was used for the calibration in this energy range [73]. As it was mentioned above, the calibration spectrum was summarized during a long time, and because the satellite was single-axis solar-oriented the flux during the period of the calibration spectrum accumulation was considered as isotropic. Correspondingly, in this case the center of the characteristic feature from the neutral pions decay was at 67.5 MeV [88].

Fig. 10

Summarized calibration energy spectra in the high-energy band in the equatorial region (a, b) and in the polar caps one (c, d) according to the AVS-F data

Primary in-flight calibration of the AVS-F apparatus in the high-energy band was made during the initial period of the AVS-F apparatus operation by using the spectrum resulted from summarizing of the spectra for 2,992 equatorial orbit segments with total accumulation time of approximately 30 h (Fig. 10a, b). There were three characteristic features separated from the spectrum [73].

The first one was identified as a sum of nuclear lines produced as a result of spacecraft materials activation (as it was already mentioned above, its maximum is located at 7.62 MeV).

The nature of the second (2) and the third (3) features was determined on the basis of the spectrum summarized from 1,786 polar cap orbit segments with total accumulation time of about 18 h (Fig. 10c, d). Geomagnetic rigidity threshold in the polar caps region ( ∼ 2 GeV) is essentially lower than in the equatorial one ( ∼ 14. 7 GeV), and the protons energy spectrum has power law shape with negative index; therefore the spectral feature caused by the protons ionization losses was more intensive in the polar cup regions accumulated spectrum than in equatorial one, i.e., the feature (2) corresponds to the relativistic protons ionization losses. Location of this feature maximum was determined as the results of relativistic protons passing through the SONG-D detector numeric simulations, but detailed discussion of this problem is outside of the frames of the present book.

So the third feature was associated with registration of γ-quanta from \({\pi }^{0}\) decay (as was mentioned above, its maximum was located at 67.5 MeV). According to the results of the in-flight calibration, the AVS-F apparatus operational range in the high-energy gamma-emission registration mode was \((4.4 \pm 1.4) \div (94 \pm 3)\) MeV in November–December 2001, and dependance of the energy E from the channel number N was described with the following function [73]:
$$\displaystyle{ E(\mathrm{MeV}) = (4.4 \pm 1.4) + N \times (0.36 \pm 0.01). }$$
(7)
The AVS-F apparatus calibration characteristics in the high-energy band also varied with time due to the same effects as in the low-energy region.
Fig. 11

Summarized energy spectrum in the equatorial region according to the AVS-F apparatus data for January 2005, multiplied by the number of channel N

The summarized equatorial region energy spectrum according to the January 2005 data is presented in Fig. 11 to illustrate the applicability of this feature for the calibration. This spectrum was multiplied by the channel number to identify spectral features more distinctly. In this figure as well as in Fig. 10a, two spectral features were separated: the first of them corresponds to the sum of activation lines (as was mentioned above, it is located at 7.62 MeV), and the second one associated with gamma-emission from π0-mesons’ decay. The analysis has shown that in January 2005 high-energy gamma-range of the AVS-F apparatus was from 2 MeV up to 260 MeV [29].

Typical Burst Events

About 1,100 burst events with duration more than 2 s were identified due to the results of the AVS-F data analysis for the period from August 2001 till December 2005. All of these events were observed outside of the radiation belts and SAA.

Fig. 12

Temporal profile of the event observed in the Earth’s shadow on January 5, 2005, in the low-energy γ-band of the AVS-F apparatus

Fig. 13

Temporal profiles of the event of July 10, 2002, in the energy band of 0.1–14 MeV (a) and one of December 26, 2004, in the energy band 0.1–19 MeV (b) observed outside the Earth’s shadow

Several events types were separated by the analysis of the observed burst events:
  • 68 % were quasistationary equatorial precipitations—see the section “Characteristics of the Quasistationary Equatorial Precipitations”;

  • 7 % of the detected events were associated with solar flares and were confirmed by the data of other experiments (GOES, RHESSI etc.)—see the section“Solar Flares Characteristics Analysis”;

  • 3 % of the identified events were gamma-ray bursts (GRB), also confirmed by the data of other experiments (SWIFT, HETE, RHESSI etc.)—see the section “Analysis of the Gamma-Ray Bursts Characteristics”;

  • 22 % of the detected events were needed more detailed analysis.

17 % of all the detected events (except solar flares) were observed in the Earth’s shadow. Unidentified events were observed both in the Earth’s shadow (Fig. 12) and out of it (Fig. 13).

Characteristics of the Quasistationary Equatorial Precipitations

Average counts rate value of the AVS-F apparatus in the low-energy γ-band in the range of geographical latitude from − 30 up to + 40 was monotone decreased along the direction to the geomagnetic equator, and was monotone increased along the direction to the high latitudes, i.e., typical counts rate temporal (latitudinal) profile without burst events had one wide minimum in the region of geomagnetic equator. The second-degree polynomial was not enough for approximation of the minimum’s width, it was necessary to use the forth- or the fifth-degree polynomial [5, 17]—see the section “AVS-F Apparatus Background Model in the γ-Bands.”

Fig. 14

Typical temporal (latitudinal) profiles for the equatorial region: without precipitation (a) and with precipitation (b) according to the data of the AVS-F apparatus in the low-energy γ-band in the same coordinate intervals. From [20]

Fig. 15

Temporal (latitudinal) profile of the hard X-ray background in the energy range of 20–100 keV according to the data of the LEGRI instrument. Excess of the counts rate over the mean model value in the interval of 12,500–14,500 s (marked by the arrow) is analogous to the quasistationary precipitations observed by the AVS-F apparatus (adopted from [98]). The averaged model of the LEGRI background is shown by dashed line, experimental data—by solid one. From [23]

During data analysis at some equatorial orbit parts for the low-energy γ-band there was found 15–30 % counts rate increases above its average value obtained by approximation of these parts with polynomials in the range of geographic latitude from − 25 up to + 30. These effects were called quasistationary equatorial precipitations [72]—see Fig. 14.

Analogous events were observed in 1997 by the LEGRI instrument on board the Spanish satellite MINISAT-01 (initial altitude of the orbit—600 km, inclination—28. 5) in the energy band of 20–100 keV [98]. In Fig. 15 an event of precipitation observed in 1997 by the matrix of the LEGRI instrument consisted of 20 CdZnTe detectors, each of 2 mm thick and 1 sm2 is presented.

Fig. 16

Typical temporal (latitudinal) profiles of precipitations: (a) type I, (b) type II, (c) type III. Arrows below correspond to the precipitation indication at the counts rate maps (see Figs. 20 and 21). From [24]

Integration time was 100 s, i.e., increasing of the counts rate during the time interval of 12,500–14,500 s is statistically significant ( > 3σ), but it cannot be explained by the activation of the material of the detectors and satellite, because it was observed sufficiently long time after the last satellite passage of the SAA region. Unfortunately, previously these events were not studied and not marked out as separate events class; its detailed analysis started only during the AVS-F apparatus data analysis [19, 20, 21, 22, 24].

Fig. 17

Temporal (latitudinal) profile of the IV type precipitations (a) and of very faint symmetric precipitations (b). The upper histogram in (b) panel presents the event without background subtraction, the curve shows the approximating background polynomial, and the lower histogram demonstrates the event with background subtraction. From [21]

Quasistationary precipitations were associated with the CORONAS-F satellite passages several orbit segments with counts rate increases in the low-energy band mainly in the region of geomagnetic equator.

Fig. 18

Typical temporal profiles of the short time precipitations of I (a) and II (b) types according to the AVS-F apparatus data in the energy range of 0.1–11 MeV. From [21]

Fig. 19

Typical temporal (latitudinal) profile of type I precipitation observed by the AVS-F apparatus in the low-energy γ-band in the same coordinate interval ∼ 24 h after the observation of the event presented in Fig. 16a. From [111]

So far about 700 precipitations are identified during the analysis of the part of AVS-F apparatus database. Temporal (latitudinal) profiles of the most part of the precipitations ( ∼ 44 %) are characterized with sharp counts rate rise toward South from geomagnetic equator and its slow decrease toward North. Typical temporal (latitudinal) profiles of the ∼ 21 % analyzed events, on the contrary, have sharp increase of the counts rate toward North and slow drop toward South from geomagnetic equator (see Fig. 16b), and  ∼ 4 % of precipitations have essentially symmetric temporal (latitudinal) profiles (see Fig. 16c).

These three types of precipitations were observed regardless of the spacecraft orbit altitude. Precipitations with more significant (than during the events of the I–III types) counts rate increase 1.3–1.8 times above the background value with central maximum were registered since the beginning of the 2002 (Fig. 17a). Such events were ∼ 4 % of the detected precipitations. Moreover several tens of faint events with symmetric profile shape were observed—see Fig. 17b. So basing on the type of the temporal (latitudinal) profiles all the quasistationary equatorial precipitations can be separated at least in four basic types [22, 23]. Temporal (latitudinal) profiles of all detected precipitations are smooth, without any statistically significant thin structure in the time scale more than 16 s.

Typical duration of the precipitations was 7 ÷ 10 min for the all types events (the size of the region along geographic latitude was 20÷ 35) [20], but there were also short precipitations ∼ 3 min among the events of I and II types (their range is  ∼ 10) [22]—see Fig. 18. Quasistationary precipitations were observed both out of the Earth’s shadow and in the Earth’s shadow [19].

Such precipitations were observed at several subsequent orbit passes through the same region. Average time interval during which the quasistationary equatorial precipitations were observed in the region of 10 of geographic longitude and 30 of geographic latitude was ∼ 24 h, maximum one was more than 8 days [20]. Figure 19 presents the temporal profile of I type precipitation observed a day after one presented in Fig. 16a in the same coordinates range.

The forth type of precipitations and faint events with symmetric profile shape were found not long ago and its characteristics detailed analysis is still in progress. Therefore only the precipitations of I–III types features are discussed in this section.

The most part of the precipitations of I–III types were located essentially symmetrically related geomagnetic equator in the band of about 40 width, the width of the near-equator region where the precipitations of the IV type were observed was about 20 [20, 21, 22]. The counts rate map in the low-energy gamma-band averaged through 1.5 years of the apparatus operation with indication of the quasistationary equatorial precipitations regions is presented in Fig. 20. Projection of charged particles precipitation regions detected in different experiments on this map is presented in Fig. 21. So, the most part of the quasistationary equatorial precipitations were located in the regions of detection of electrons precipitations at the low latitudes [40] (L ∼ 1. 5—see Fig. 21) and in the region of geomagnetic equator. Precipitations of the electrons with energy E ∼ 1. 3 MeV were observed at the altitudes of 288–350 km in the regions with L = 1. 14–1.17 as early as in 1960s of the twentieth century [67]. Precipitations of the ions of hydrogen, helium, and oxygen with maximum in the region of geomagnetic equator but extended to geomagnetic latitude of ± 20 were detected by some spacecrafts, its flux intensity increases in the layer of 180–260 km, and then does not change. The detectors on board the COSMOS-900 satellite observed both day- and night-time electron precipitation at the altitude of 500 km [40].

Fig. 20

Counts rate map in the low-energy gamma-band averaged during 1.5 years of the apparatus operation. Lines colors depend on precipitation type (see Fig. 16). From [23]

Fig. 21

Registered during several low-orbit experiments charged particles precipitation regions projection at the map presented in Fig. 20

Fig. 22

Typical energy spectra of first three types quasistationary equatorial precipitations. From [23]

Fig. 23

Counts rate temporal profiles in the region with precipitation according to the data of the AVS-F (a) and MKL (b)

Fig. 24

Distributions of the recurrence frequencies of Kp-indices (black squares, low and left axes) and of Dst-indices (white circles, upper and right axes) for the period from September 2001 till February 2002. From [23]

Fig. 25

Precipitations number distributions on Kp-indices (black squares, low and left axes) and on Dst-indices (white circles, upper and right axes) for the types I (a) and II (b) events. From [23]

Fig. 26

Precipitations number distributions on Kp-indices and Dst-indices for the types I (a, b) and II (c, d) events taking into account corresponding indices recurrence frequencies during the observation time. From [111]

Fig. 27

AVS-F counts rate temporal profile in the low-energy γ-band during the precipitation detected at the end of 2004

Typical energy spectra of quasistationary equatorial precipitations are presented in Fig. 22. For all three types of precipitations the spectra are power-law [24]:
$$\displaystyle{ I \sim {E}^{-\alpha },\text{ where }\left \{\begin{array}{@{}l@{\quad }l@{}} \alpha = 2.1 \pm 0.2,\text{ for precipitations of I and III types},\quad \\ \alpha = 1.8 \pm 0.1,\text{ for precipitations of II type}. \quad \\ \quad \end{array} \right. }$$
(8)

Shape of the spectra allows to make the conclusion that increasing of the gamma-quanta counts rate in the low-energy band of the AVS-F apparatus for some equatorial CORONAS-F satellite orbit segments was probably caused via interactions of these regions located charged particles with the material of the detector and the spacecraft.

But preliminary data analysis had shown the absence of correlation of AVS-F apparatus counts rate in the low-energy gamma-band during the quasistationary equatorial precipitations and flux of electrons (in the 0.3–0.6 MeV and 0.6–1.5 MeV bands) and protons in the range of 1–5 MeV according to the data of Cosmic Rays Monitor (Russian abbreviation is MKL) also mounted on board the CORONAS-F satellite (see description in the chapter “Scientific Set of Instruments “Solar Cosmic Rays””). Probably this effect is associated with non-sufficient sensitivity of this device (effective area of the SONG-D detector is almost ten times bigger). Only correlations of the counts rate latitudinal dependence in the regions without precipitations were observed [19, 24]. Comparison of the counts rate temporal profiles according to the AVS-F apparatus data (on the region with precipitation) and to the MKL data (at the same time interval but without any peculiarities) is presented in Fig. 23.

We have analyzed the number of the detected precipitations dependence from the geomagnetic activity level [21, 22]. A series of sequential precipitations detected from September 2001 till February 2002 were selected for the analysis. Distributions of the precipitations recurrence frequency on the Kp- and Dst-indices during the studied time intervals are presented in Fig. 24. Distributions of the precipitations amount on Kp- and Dst-indices for the events of I and II types are shown in Fig. 25a, b, and normalized amount precipitations distributions on Kp-indices for events of I and II types taking into account Kp-indices recurrence frequency are presented in Fig. 26. Corresponding subsets volumes were 251 and 118 events for the precipitations of I and II types correspondingly.

The II type precipitations recurrence frequency increased with geomagnetic level activity increasing at the 95 % significance level [21]. Such tendency was also observed for the precipitations of I type [22, 23]—see Fig. 26. It can be associated with an effect found in the BATSE experiment, where increasing of the frequency of electrons precipitations caused by powerful UHF-transmitters (in particular, its bremsstrahlung) related to the increasing of geomagnetic activity level was observed [65]. Unfortunately, the volume of the III type precipitations subset (21 events) during the analyzed time interval is not sufficient for identification of any relation.

Besides, essential variations of the precipitations amount depending on the CORONAS-F satellite orbit altitude were not observed. During the period from November 14, 2001, till January 12, 2005, the orbit altitude decreased from 510 km down to 380 km. Two samples of the AVS-F apparatus data were studied: 46 precipitations observed during 9 days from November 14 till November 22, 2001 (exposure of 622,777 s, altitude ranges of 492 ÷ 532 km), and 19 precipitations registered during 9 days from January 3 till January 12, 2005 (exposure of 318,410 s, altitudes range of 362 ÷ 398 km). Taking into account normalizing to the exposure time these two values can be considered as coinciding in the limits of the statistic errors [19], but probably larger data samples analysis will reveal insignificant differences.

Configuration of the location area of the charged particles produced, detected by the AVS-F apparatus gamma-quanta via interactions with materials of detector and satellite, was depended on altitude: during the period from 2001 to 2004 the ratio of the AVS-F apparatus counts rate during the quasistationary equatorial precipitations to the background one counts rate decreased twice in the low-energy gamma-band (average altitude of the CORONAS-F satellite orbit decreased from 510 down to 390 km)—Figs. 27 and 16a.

Analysis of the Terrestrial Gamma-Ray Flashes Characteristics

As it was mentioned in the section “AVS-F Apparatus Short Description,” after the burst trigger the temporal profile with 1 ms time discretization was recorded in the low-energy band during 4.096 s regardless duration of the detected event. During the experiment short events with duration of several milliseconds were registered [3, 31].

The observed short events can be caused by the following instrumental reasons [4]:
  • fluorescence of CsI(Tl) after high-energy charged particle passing through the SONG-D detector,

  • fluctuations of the number of photoelectrons or ions in the photomultiplier after high-energy charged particle passing through it;

  • processes in the electronics system produced by huge energy deposition in the SONG-D detector.

But part of the events can be caused by the terrestrial gamma-ray flashes (TGF)—see Fig. 28, analogous to the γ-events, discovered several years ago during analysis of the BATSE data. These events were registered at the near-equatorial latitudes (\({0}^{\circ }\div 3{0}^{\circ }\)) [50]. The source of the TGF observed during the BATSE experiment was the Earth’s atmosphere; moreover the flashes were observed in spite of the fact that the events coming from under the Earth’s horizon had to be eliminated effectively [66].

Fig. 28

Terrestrial gamma-ray flashes typical temporal profiles according to the AVS-F data. From [31]

Fig. 29

Terrestrial gamma-ray flashes typical temporal profiles according to the BATSE data. From [31]

Fig. 30

Physical phenomena associated with lightning discharge in the upper layer of the Earth’s atmosphere (http://elf.gi.alaska.edu,http://umbra.nascom.nasa.gov): (1) the scheme of γ-emission generation during the lightning discharge; (2) color photo of the red sprite (RS) observed during the thunderstorm of July 4, 1994; (3) black-and-white photo of the blue jet (BJ) observed during the thunderstorm of July 1, 1998, above Florida; (4) black-and-white photo of light flashes during the thunderstorm of October 21, 1989, at night above Argentina, made by the camera on board space shuttle; (5) color photo of sub-ms ionospheric flash (elve) observed during the thunderstorm of July 1, 1998, above Florida; (6) distribution of light flashes intensity during the thunderstorm of March 9, 1998, above Florida according to the data of American–Japan semiconductor camera LIS (Lightning Imaging Sensor) on board the TRMM (Tropical Rainfall Measuring Mission) satellite which was launched on November 28, 1997. From [3]

Terrestrial gamma-ray flashes lasted for several milliseconds, their spectra were very hard, for some events gamma-emission with energy up to 17 MeV was observed by the RHESSI experiment (http://scipp.ucsc.edu/~dsmith/tgf/). Typical temporal TGFs profiles according to the BATSE instrument in the energy band of 0.02–10 MeV are presented in Fig. 29.

It is supposed that these events were associated with thunderstorm phenomena in the upper layers of the Earth’s atmosphere: they occurred during electric discharges between the upper clouds layer and the ionosphere. During this process at least four types of physical events are observed, except the lightning itself—see Fig. 30: red sprites (RS), blue jets (BJ), submillisecond ionospheric flashes (Elve), and TGF; moreover optic emission was also observed by cameras on board spacecrafts [70]. Blue jets are blue light beams (in many cases with violet component), which occur in the upper part of the charged cloud structure and directed toward the lower part of the atmosphere, and they scatter at the altitudes of 40 ÷ 50 km [107]. Red sprites are optic flashes of red color, observed at the altitudes of 50–90 km directly over the thunderstorm cloud during lightning [70, 86]. Submillisecond ionospheric flashes caused by the fluorescence of nitrogen during lightning directed toward the lower part of ionosphere [70]. TGFs occur during the interaction of the atmosphere’s matter and so-called runaway electrons, i.e., electrons produced during ionization of the Earth’s atmosphere molecules by the cosmic rays and later accelerated during multiple scattering and interaction with the thunderstorm formation electromagnetic field. Obviously the most part of the electrons is thermalized during multiple scattering; however, the density of the electrons with energy of Ee > 1 MeV at the altitude of ∼ 10 km is ∼ 10−5 cm−3 [102]. Consequently, TGFs are electrons bremsstrahlung emission directed along the electron beam; moreover average energy of gamma-quanta is ∼ 1 MeV, energy released during the flash—E = 109 erg, luminosity—L = 1012 erg/s [68, 86].

Fig. 31

(a) Duration distributions for following subsets: 498 short events detected by AVS-F apparatus during January 18–20, 2003 (normalized to the sample volume), 65 TGFs registered by the BATSE instrument and 47 TGF observed by AVS-F. From [3]; (b) temporal profile of the TGF registered during the tropical thunderstorm Beni according to the AVS-F data. From [4]

Fig. 32

TGF observed by the data of the AVS-F apparatus on July 19, 2004, at about 21:20 UT in the low-energy gamma-band was very close in coordinates to the storm formation as well as TGF, detected by the RHESSI instrument on the same day at 21:24:01.530 UT. From [4]

TGF identification from the AVS-F apparatus database was based on temporal profiles fractal analysis, because all background fluctuations (including those causing short events resulting from instrumental reasons) in the AVS-F apparatus in the low-energy gamma-band were Poisson at the satellite orbit segments outside the radiation belts and SAA. Therefore, the time distribution of intervals between separate events contributed in the value of counts rate were exponential [31].

Fractal index of such temporal profiles was about 1.5, if it is possible to consider the counts rate mean value as a constant in the limits of the studied time interval [53, 59] (it is true for the AVS-F apparatus, because duration of each analyzed temporal profile is 4,096 ms). At the present time 47 events not associated with instrumental effects were identified from the AVS-F database [31].

Identified events are similar to TGF in duration, temporal profile’s shape, and duration distribution [3, 4, 31]. Duration distribution for TGF is wider than for short events caused by instrumental effects—see Fig. 31a.

One of the events identified in theAVS-F apparatus database was detected during a powerful tropical thunderstorm Beni, and it proves its correct interpretation as TGF. This TGF was located not far from the center of the thunderstorm (Fig. 31b). Now weather conditions during the other 44 events are analyzed.

Gamma-emission during TGF is directed, width of the beam is less than one degree even taking into account scattering; therefore it is impossible to observe one and the same flash by different detectors simultaneously. But two TGFs were observed by the AVS-F apparatus on July 19, 2004, at about 21:20 in the low-energy gamma-band, coordinates of the CORONAS-F satellite during this period were close to the coordinates of the RHESSI spacecraft, which detected TGF at the same day at 21:24:01,530 (http://scipp.ucsc.edu/~dsmith/tgf/). Consequently AVS-F and RHESSI observed the processes occurred during one and the same thunderstorm formation [4]. Temporal profiles of these events according to the AVS-F apparatus data are presented in Fig. 32.

Analysis of the Gamma-Ray Bursts Characteristics

During the period from August 2001 till December 2005, there were over 30 gamma-ray bursts (GRB) detected by the AVS-F apparatus [25, 36].

As it was mentioned above, the minimum time for spectral information accumulation for the AVS-F was about 1 s; therefore all detected gamma-ray bursts lasted over 2 s.

Comparative characteristics of the AVS-F apparatus and other detectors of GRB [25] are operated during the same period are presented in Table 2.

Typical example of temporal profile of the gamma-ray burst detected by the AVS-F apparatus is presented in Fig. 33. The burst was observed in the equatorial region of the CORONAS-F satellite orbit. The most part of the registered by the AVS-F apparatus events were also observed by other detectors of gamma-ray bursts, for instance, by the SWIFT/BAT, RHESSI, “Konus,” and HETE [36].

Gamma-ray burst GRB050126 (z ≈ 1. 26 - see http://www.mpe.mpg.de/~jcg/grbgen.html) was observed simultaneously by the AVS-F apparatus in the low-energy gamma-band and by the SWIFT/BAT [47] at 12:00:53 UT —see Fig. 34. Duration of this burst was t90SWIFT ≈ 26 s according to the SWIFT data (http://swift.gsfc.nasa.gov/docs/swift/archive/grb_table.html/), and t90AVS ≈ 80 s according to the data of the AVS-F apparatus (values of t90 can be different depending on the sensitivity and energy band of the detector registered it). Maximum energy of γ-quanta observed during this burst by the AVS-F apparatus was Emax = 0. 37 ± 0. 03 MeV.

Table 2

Comparative characteristics of the AVS-F apparatus and other GRB detectors

Characteristics

AVS-F

RHESSI

SWIFT/BAT

GGS-Wind Konus

 

Effective

 ∼ 300a

 < 300

5200

200

 

area (cm2)

     

Field of

 ∼ 2π

2π

2π

4π

 

wiev (sr)

     

Detector

CsI(Tl)

Ge

CdZnTe

NaI

 

Energy

0.05–11

    

band (MeV)

4–94

    
 

(in 2001)

0.05–17

0.015–0.15

0.01–10

 
 

0.08–22

    
 

2–260

    
 

(in 2005)

    

Energy

86 keV

 < 3 keV

3.3 keV

  

resolution

(13 %)

for 100 keV

for 60 keV

100 keV

 

(FWHM)

for 660 keV

 < 5 keV

100 keV

for 660 keV

 
  

for 500 keV

for 660 keV

  

a For the events detected only by the upper surface

Fig. 33

The example of gamma ray burst detected by the AVS-F apparatus and HETE-2 instruments. The first counts rate increase corresponds to the radiation belt, the second one—GRB020214. Temporal profiles of the burst are presented in three energy bands: 0.1–11 MeV (1), 0.41–11 MeV (2), and 0.563–2.34 MeV (3). From [9]

Fig. 34

GRB050126 temporal profiles according to AVS-F and SWIFT/BAT data. From [25]

Fig. 35

GRB030328 temporal profiles according to AVS-F and HETE data. From [25]

Fig. 36

GRB021008 temporal profiles according to AVS-F and RHESSI data. From [25]

Fig. 37

GRB050525 temporal profiles according to AVS-F and RHESSI data. From [36]

Fig. 38

Energy spectra of the GRB021008, GRB030328 and GRB050525 according to the data of the AVS-F apparatus. From [25]

The burst GRB030328 (z ≈ 1:52 - see http://www.mpe.mpg.de/~jcg/grbgen.html) detected at 11:20:58 UT, was observed simultaneously by the HETE and AVS-F, t90HETE ≈ 100 s (http://space.mit.edu/HETE/Bursts/), t90AVS ≈ 80 s. Its temporal profile is presented in Fig. 35. This burst is more hard than the GRB050126—the maximum energy of γ-quanta detected by the AVS-F apparatus was Emax = 0. 68 ± 0. 03 MeV.

For some GRBs emission in the high-energy γ-band of the AVS-F apparatus was also detected during the time intervals corresponding to their duration according to the data of the SWIFT, HETE, and RHESSI [25, 37]. Unfortunately, redshifts are not determined for all bursts during which the high-energy γ-emission was observed by the AVS-F apparatus (http://www.mpe.mpg.de/~jcg/grbgen.html).

Gamma-emission during the GRB021008 (beginning at 07:00:50 UT according to the data of the RHESSI instrument) was registered in the energy band up to 7 MeV, i.e., it was detected in both γ-bands of the AVS-F apparatus. Temporal profiles of this burst by the RHESSI (http://grb.web.psi.ch/grb_list_2002.html) and AVS-F data in different energy ranges are presented in Fig. 36. Duration of this burst according to the data of the RHESSI instrument was t90RHESSI ≈ 13 s in the range of 0.025–0.5 MeV, and according to the data of the AVS-F apparatus t90AVS ≈ 9 s in the range of 0.1–7 MeV.

Gamma-emission of maximum energy was observed by the AVS-F apparatus during the burst GRB050525 [36], observed simultaneously by the RHESSI instrument (http://grb.web.psi.ch/grb_list_2005.html) and the AVS-F apparatus at 00:49:50 UT. Its temporal profiles in different energy ranges according to the data of both experiments are presented in Fig. 37. Maximum energy of γ-quanta detected by the AVS-F apparatus for this burst was Emax = 147 ± 3 MeV. During the period of CORONAS-F satellite operation only AVS-F apparatus used the signal from the SONG-D detector and itself detector SONG in MKL instruments complex could provide registration of such high energy gamma-emission. Other analogous instruments were out of operation this time.

Typical energy spectra of the gamma-ray bursts according to the data of the AVS-F apparatus are presented in Fig. 38. There are no distinct spectral features in these spectra, and it is in agreement with the RHESSI instrument data in the range of 100–1500 keV [108].

Solar Flares Characteristics Analysis

Analysis of the energy spectra and time behavior of the X-ray and gamma-emission in wide energy range during solar flares allows to obtain important information about the processes of particles acceleration in the solar flares, and about the chemical composition of the accelerated particles and surrounding solar atmosphere [58, 60, 61, 81, 94, 95].

Solar flares were observed by the various detectors on board different spacecrafts (HEAO-1, HEAO-3, OSO-7, HINOTORI, CGRO, SMM, GRANAT, RHESSI, YOHKOH, SOHO, CORONAS series satellites, etc.). Taking it into account the volume of information about solar flares obtained by different instruments the observation data systematization and cataloguing become more and more important allows to simplify and promote comparison, analysis, and interpreting of the results obtained by various experiments. Now several catalogues with detailed information about the observed solar flares are published (see, for instance, [64, 82, 103]). Full catalogue of the flares from October 2002 till to the present day according to the data of the GOES, SOHO, RHESSI, YOHKOH, SDAC, LASCO, and TRACE experiments is located at http://www.lmsal.com/solarsoft/latest_events_archive.html and is updated permanently.

According to the results of the data analysis two catalogues of solar flares detected in the low- [18] and high-energy [29] ranges of the AVS-F apparatus were composed.

Catalogue of Solar Flares in the Low-Energy Gamma-Band According to the Data of the AVS-F Apparatus On board the CORONAS-F Satellite During 2001–2005

Over 60 solar flares of class stronger than M2.0 (according to the GOES classification) were detected by the AVS-F apparatus in the low-energy gamma-band during the period from August 2001 till the beginning of December 2005. Over 30 of them were more intensive than M5.0 [11, 18].

In some cases the series of close in time powerful solar flares (with class more than M1.0) originated from the same active region were observed. For instance, in January 2005 over 200 solar flares were registered (moreover 27 of them were of M and X classes) by the detectors on board the GOES, RHESSI, SOHO, and other satellites. These flares can be grouped in the series with the active regions NOAA 10715—NOAA 10729 sources (http://www.lmsal.com/solarsoft/latest_events_archive.html). Some of the active regions produced only small flares, below C1.3 class—AR 10724, AR 10725, AR 10727, and AR 10729, while the region NOAA 10720 was a source of several flares of X class.

Six of 27 powerful flares of January series were also observed by the AVS-F apparatus [15, 32, 33, 34]. An active region NOAA 10720 produced five of them, and NOAA 10719—the other one. Moreover, during this period the AVS-F apparatus registered hard X-rays and γ-rays in the range of E > 100 keV during some flares of B and C classes (for more detailed discussion see the section “Hard X-ray and Gamma-Emission During Faint Solar Flares”).

Another several series of the flares were observed during the period from November 3 till November 10, 2004 (http://www.lmsal.com/solarsoft/latest_events_archive.html) [109]: during this interval about 100 solar flares were registered (16 of them were of M and X classes) originated from the active regions 10689, 10691, 10693, 10696, and 10698. Moreover AR 10696 was a source of over 50 flares, 15 of which were more powerful than M1.0 class.

During the period from October 19 till November 15, 2003, eight active regions were detected on the Sun. They produced over 200 solar flares, and six of these active regions (10484, 10486, 10488, 10490, 10498, 10501) produced hard X-ray and γ-emission (http://www.lmsal.com/solarsoft/latest_events_archive.html). During this period detectors on board the GOES, RHESSI and other satellites detected 60 solar flares stronger than M1.0 class. Several of these flares were also detected in the various experiments on board the CORONAS-F satellite [104], and five of them were observed by the AVS-F apparatus [11, 12, 16].

For the solar flares majority the hard X-rays and gamma-emission were observed during the rise phase of the soft X-rays according to the data of the detectors on board the GOES series satellites, for some events it was registered during its maximum [14]. Usually the gamma-emission duration during solar flares in the low-energy range of the AVS-F apparatus was essentially smaller than the duration of their X-rays emission in the ranges of 0.1–0.8 nm and 0.05–0.4 nm according to the GOES satellites data, and summarized temporal profiles in the low-energy range has simple structure with one maximum as in X-ray range [14, 18]. But for several solar flares duration of hard X-ray and γ-emission substantially coincides with the duration of the soft X-rays emission [14]. Besides, during some flares several episodes of detection of hard X-ray and γ-rays associated with the temporal profile features in the soft X-ray range (see, for instance, p. 225).

Among the flares of all the above-mentioned types there are events both with lines in energy spectrum and with smooth spectra, i.e., e-dominant.

During some events (including small flares) temporal profile’s thin structure with timescale of approximately 30 ÷ 160 s and 7 ÷ 35 ms was observed in the AVS-F apparatus low-energy gamma-range both in the bands corresponding to flare spectral continuum and identified spectral lines.

Solar Flares Temporal Profiles

One of the typical examples of the flares with gamma-emission observed during the rise phase of the soft X-rays emission was the flare of January 20, 2005 (X7.1) [15]. This event was the most powerful one from the series of this period (see p. 217).

It began at 06:36 UT according to the data of the detectors on board the GOES series satellite, finished at 07:26 UT, and maximum of the soft X-rays emission was observed at 07:01 UT (http://www.swpc.noaa.gov/ftpdir/warehouse/2005/2005_events.tar.gz). The source of this flare was the active region NOAA 10720. The flare of January 20, 2005, was accompanied with the coronal mass ejection (CME), and also the proton event and the GLE N 69 (Ground Level Event) were the most intensive ones beginning from 1978 and 1956, respectively—see, for instance, [43, 48, 87]. Temporal profiles of hard X-rays and γ-emission from this flare in the range of 0.1–20 MeV according to the data of the AVS-F apparatus are presented in Fig. 39.

Fig. 39

January 20, 2005 solar flare temporal profile by the data of the AVS-F apparatus (with background subtraction) in the energy range of 0.1–20 MeV and one of by the GOES-12 satellite data in the band of 0.1–0.8 nm. Time interval when the CORONAS-F satellite passed through the Earth’s radiation belt is marked by the arrow RB. From [33]

Fig. 40

Temporal profiles of the solar flares observed on November 3–4, 2004, according to the data of the AVS-F apparatus (with background subtraction) and the GOES-12 satellite. Time intervals when the CORONAS-F satellite passed through the Earth’s radiation belt are marked by hatched regions RB. From [33]

Some of the events of November 2004 series also had similar temporal profile type (see p. 218), in particular, the flares of November 3 and 4 (of M1.6 and M5.4 classes, respectively) originated from the active region NOAA 10696. Their temporal profiles according to the data of the AVS-F and GOES-12 are presented in Fig. 40b, c. The flare of November 3 began at 03:23 UT according to the data of the detectors on board the GOES-12 satellite and ended at 03:57 UT (http://www.swpc.noaa.gov/ftpdir/warehouse/2005/2004_events.tar.gz) [109], its emission in the range of 0.1–19 MeV was observed by the AVS-F apparatus in the polar region of the CORONAS-F orbit. The flare of November 4 was detected in the equatorial part of the CORONAS-F orbit, its soft X-rays according to the GOES-12 data was observed from 22:53 UT till 23:26 UT (http://www.swpc.noaa.gov/ftpdir/warehouse/2005/2004_events.tar.gz) [109].

Hard X-rays and gamma-emission of the flares of April 9, 2003 (of M2.5 class) and October 26, 2003 (of M7.6 class) were also registered during the X-rays rise phase of [14]—see Fig. 41a, b. The first of these flares began at 23:23 UT and ended at 23:34 UT according to the data of the GOES-10 satellite (http://www.swpc.noaa.gov/ftpdir/warehouse/2003/2003_events.tar.gz). Its source was the active region 10326.

Fig. 41

Temporal profiles of the solar flares of April 9, 2003 (a), from [18], October 26, 2003 (b), from [18], and July 17, 2002 (c), from [14], in the low-energy γ-band according to the data of the AVS-F apparatus (with background subtraction) and ones in soft X-ray bands according to the data of GOES series satellites. Beginning of time interval when the CORONAS-F satellite was passing through the Earth’s radiation belt is marked by the arrow RB

The event of October 26, 2003, was one from the solar flares series of October–November, 2003 (see p. 219). Its source was an active region NOAA 10484 (N01W38), flare begin, maximum and end were registered in the soft X-rays band according to the data of the GOES-12 satellite at 21:34 UT, 21:40 UT, and 21:48 UT correspondingly (http://www.swpc.noaa.gov/ftpdir/warehouse/2003/2003_events.tar.gz). Unfortunately, during this flare maximum the CORONAS-F satellite passed into the radiation belt, but gamma-emission of this flare in the low-energy range of the AVS-F apparatus was recorded in the near-equator region of the satellite’s orbit in the time interval from 21:36:52 UT till 21:37:56 UT [16].

The solar flare of July 17, 2002 (of M8.5 class) was a characteristic illustration of the type of solar flares, during which hard X-rays and γ-rays were observed during the maximum of the soft X-rays emission [14]—see Fig. 41c. According to the data of the instruments on board GOES-10 satellite this flare began at 06:58 UT, ended at 07:19 UT, and maximum of its soft X-rays emission was observed at 07:13 UT (http://www.swpc.noaa.gov/ftpdir/warehouse/2002/2002_events.tar.gz). Its source was an active region 10030. One of the series of November 2004 flares (November 3, M2.8 class) also had such type temporal profile. This flare was originated from the active region 10691, its soft X-rays emission was observed from 01:26 UT till 01:36 UT according to the data of the instruments on board GOES-12 satellite (http://www.swpc.noaa.gov/ftpdir/warehouse/2005/2004_events.tar.gz). Temporal profiles of the flare of November 3, 2004 according to the AVS-F data (with background subtraction) and to the data of the instruments on board GOES-12 satellite are presented in Fig. 40a.

The events of January 15 and 17, 2005, are also examples of this type of flares [15, 32, 33]. They were from January flares series (see p. 217), produced by an active region of NOAA 10720. The flare of January 15, 2005 (of X2.6 class) was observed during the period of 22:35–23:31 UT according to the data of the instruments on board GOES series satellites (http://www.swpc.noaa.gov/ftpdir/warehouse/2005/2004_events.tar.gz). During the maximum of the soft X-rays (23:02 UT according to the data of the GOES-12 satellite) the AVS-F apparatus registered hard X-rays and γ-emission [33]—see Fig. 42a. Solar flare of January 17, 2005 (of X3.8 class) began at 06:59 UT and ended at 10:07 UT (with maximum at 09:52 UT) according to the detectors on board the GOES series satellites data (http://www.swpc.noaa.gov/ftpdir/warehouse/2005/2004_events.tar.gz). Its hard X-rays and γ-emission were observed just after the CORONAS-F satellite leave the Earth’s shadow area during maximum and decreasing of the soft X-rays emission [33]. Temporal profiles of this flare according to the data of the AVS-F apparatus (with background subtraction) in the range of 0.1–20 MeV and in the X-band according to the data of the detectors on board GOES-12 satellite are presented in Fig. 42b. During the last 9 min of the flare the CORONAS-F satellite was entered in the radiation belt, but by this time emission in the low-energy γ-band of the AVS-F apparatus already decreased to the background level [32].

Fig. 42

Temporal profiles for the solar flares of January 15, 2005 (a) and of January 17, 2005 (b) according to the data of the GOES-12 satellite in the band of 0.1–0.8 nm and the data of the AVS-F apparatus (with background subtraction). Time intervals when the CORONAS-F satellite was passing through the Earth’s radiation belt are marked by arrows RB. The moment when the CORONAS-F satellite left the Earth’s shadow (09:49:53 UT) corresponds to 845 s on the time axis

Fig. 43

October 29, 2003, solar flare temporal profiles of AVS-F counts rate in the energy bands of 0.1–17 MeV and 4–94 MeV (with background subtraction) and one of soft X-ray flux according to the GOES-12 satellite data in the band of 0.05–0.4 nm. From [16]

Fig. 44

November 4, 2003 flare temporal profile of counts rate according to the AVS-F data in the low-energy gamma-band (0.1–17 MeV) without background subtraction and one of soft X-ray flux in the band of 0.05–0.4 nm by the GOES-12 satellite data (a) and larger scale temporal profile of the first short impulse by AVS-F data in the low-energy gamma-band (with background subtraction) (b). Time intervals when the CORONAS-F satellite passed through the Earth’s radiation belt are marked by arrows RB. From [12]

Summarized temporal profiles of the flares, for which the duration of the hard X-rays and γ-emission coincides with the duration of the soft X-rays emission in the operational ranges of the AVS-F apparatus has more complicated shape, then ones in the soft X-bands according to the data of the detectors on board the GOES series satellites [12].

As an example, similar temporal profile was registered by the AVS-F apparatus during the solar flare of October 29, 2003 [84]— Fig. 43.

This flare of X10 class began at 20:38 UT, ended at 20:55 UT according to the data of the detectors on board the GOES series satellites (http://www.swpc.noaa.gov/ftpdir/warehouse/2003/2003_events.tar.gz) and was one of the series of October–November 2003 flares (see p. 219), originated from the active region NOAA 10486 (its coordinates were S15W02). Maximum of the soft X-rays of this flare was observed at 20:49 UT, but it corresponded to minimum in the energy range of 0.1–17 MeV, and maxima in this range were observed during the rise (4 maxima) and decreasing (2 minima) phases of the soft X-rays emission and were not associated with the features of its temporal profile the soft X-band [78]. Thin structure with characteristic timescale of 30 ÷ 160 s was observed at the summarized temporal profile of this flare in the low-energy range of the AVS-F apparatus.

Soft X-rays temporal profile of November 4, 2003 (of X18 class) solar flare has two sharp increases associated with the features of the temporal profile in the energy range of 0.1–17 MeV, as opposed to the flare of October 29, 2003 [12]. The first increase was accompanied by a short impulse of gamma-emission in time interval of 19:33:01–19:34:08 UT with following decrease of the emission intensity in the range of 0.1–17 MeV down to the background level, and the second one was associated with the long episode of gamma-emission in the range of 0.1–17 MeV, lasted from 19:40:00 UT till 20:23:25 UT [16]—see Fig. 44. This flare began at 19:29 UT and ended at 20:30 UT according to the data of the detectors on board the GOES series satellites (http://www.swpc.noaa.gov/ftpdir/warehouse/2003/2003_events.tar.gz). It was the most powerful from October to November 2003 series (see p. 219). The source of the flare of November 4, 2003, was an active region NOAA 10486 (S19W83). Unfortunately, during the flare’s maximum (19:44 UT according to the data of the GOES-12 satellite) the CORONAS-F satellite was passing through the radiation belt and the south polar cap [16].

If during the solar flare several episodes of hard X-rays and gamma-emission were observed, some of them could be also registered at the decreasing of the soft X-rays emission according to the data of the detectors on board the GOES series satellites, as for instance, during the flare of August 24, 2002 (of X3.1 class)—see p. 246.

Energy Spectra of the Solar Flares

Up to six spectral lines complexes were observed during some flares, corresponding to the nuclear lines, neutron capture line (2.223 MeV), annihilation line (0.511 MeV), and α α-line—7Be (0.429 MeV) + 7Li (0.478 MeV) [18]. Identified spectral features were observed during all time interval of hard X-rays and γ-rays registration by the AVS-F apparatus. Such lines were typical for the solar flares spectra (for instance, they were observed during October 27, 1999 [95] and July 01, 1991 [96] events).

Fig. 45

October 29, 2003, solar flare summarized energy spectrum (with background subtraction) during time interval 20:39:07–20:55:00 UT by AVS-F data. From [10]

In particular, during the October 29, 2003, solar flare five spectral lines complexes were identified in the summarized energy spectrum in the ranges of 0.81–0.94 MeV, 1.51–1.74 MeV, 2.6–3.4 MeV, 4.0–5.0 MeV, 5.3–6.9 MeV, corresponding to the following nuclear lines:56Fe (0.847 MeV);24Mg (1.37 MeV) +20Ne (1.63 MeV) + 28Si (1.79 MeV);20Ne (2.62 MeV) + 21Ne (3.18 MeV) +22Ne (3.22 MeV) + 16O (3.2 MeV);12C (4.44 MeV);16O (6.13 MeV) [84]. Maximum in the range of 2.14–2.64 MeV corresponding to the neutron capture line was also revealed. October 29, 2003, solar flare summarized energy spectrum (with background subtraction) during the time interval of 20:39:07–20:55:00 UT according to the data of the AVS-F apparatus is presented in Fig. 45. Analogous spectral lines were observed during this flare according to the data of the RHESSI satellite [100]. Moreover, in the range of 0.3–0.6 MeV very faint lines (for instance, annihilation line) possibly can be observed.

Four spectral lines complexes in the ranges of 0.4–0.6 MeV (α α + annihilation line), 1.7–2.3 MeV (24Mg + 20Ne + 28Si + neutron capture line), 3.2–5.0 MeV (22Ne + 16O + 12C), and 5.3–6.9 MeV (16O) were identified in the January 20, 2005, solar flare spectrum during the time interval of 06:43:16–06:59:51 UT according to the data of the AVS-F apparatus [29, 33]—see Fig. 46.

Fig. 46

January 20, 2005, solar flare summarized energy spectrum (with background subtraction) according to the AVS-F apparatus data. From [33]

Fig. 47

Summarized energy spectra of the solar flares of January 15, 2005 (a) and January 17, 2005 (b) according to the AVS-F apparatus data (with background subtraction). From [33]

Fig. 48

Spectra in the low-energy γ-band for the solar flares of July 17, 2002 (a), October 26, 2003 (b), and April 9, 2003 (c) according to the AVS-F apparatus data (with background subtraction). From [14]

In the spectrum of the January 17, 2005, flare also four complexes of lines at energies of 0.4–0.6 MeV (α α + annihilation line), 0.7–0.9 MeV (56Fe), 2.0–2.3 MeV (24Mg + 20Ne + 28Si + neutron capture line), and 3.6–5.0 MeV (12C) were observed during the time interval of 09:51:13–09:58:40 UT according to the data of the AVS-F apparatus [15, 32, 33] (see Fig. 47b).

During the time interval of 22:56:31–23:05:51 UT only two complexes of spectral lines were observed in the January 15, 2005, solar flare spectrum: in the range of 0.46–0.65 MeV, corresponding to the positron line, and in the band of 2.0–2.3 MeV, corresponding to the neutron capture one [32, 33] (see Fig. 48a).

Energy spectra of several solar flares observed by the AVS-F apparatus were not contained any gamma-lines, i.e., these flares were e-dominant [11, 14, 18]. Examples of such flares are presented in Fig. 48. Previously flares of this type were registered by various detectors, in particular, by the SMM/GRS [103].

Solar Flares Temporal Profiles Thin Structure

As it was already mentioned above, thin structure with characteristic timescale of 30 ÷ 100 s was observed in the summarized temporal profiles of the solar flares, for which the duration of the hard X-ray and γ-emission substantially coincides with the duration of the soft X-rays—for instance, see Fig. 43. The behavior of temporal profiles of the solar flares in the energy ranges corresponding to the identified spectral features was also analyzed [16, 32, 33, 34].

Fig. 49

Temporal profiles of the AVS-F counts rate during the flare of October 29, 2003, in energy bands corresponding to: (a) nuclear lines from the elements56Fe (0.81–0.94 MeV),24Mg + 20Ne + 28Si (1.54–1.74 MeV),20Ne + 21Ne + 22Ne + 16O (2.6–3.4 MeV), and 16O (5.3–6.9 MeV), (b) continuum in the energy band of 0.3–0.6 MeV, neutron capture line 2.2 MeV, and nuclear line12C (4.0–5.0 MeV). From [16]

Table 3

Spectral features of the flare of October 29, 2003, and the peaks on temporal profiles in the corresponding energy ranges

Spectral

    

features,

Center,

   

MeV

MeV

Interpretation

Peaks in temporal profile, UT

 

0.3–0.6

Continuum

20:42

20:43

20:46

20:51

 

0.81–0.94

0.86

Fe

20:42

20:45

20:46

20:48

20:51

 

1.51–1.74

1.6

Mg+Ne+Si

20:42

20:45

20:46

20:51

20:52

 

2.14–2.44

2,2

n

20:45

20:46

20:48

20:51

20:52

 

2.6–3.4

3.1

Ne+O

20:52

 

4.0–5.0

4.2

C

20:42

20:43

20:45

20:46

20:48

20:51

 

5.3–6.9

6.0

O

20:45

20:46

20:48

20:51

 

Temporal profiles of the AVS-F apparatus counts rates during the October 29, 2003, solar flare in the energy ranges corresponding to the nuclear lines of the elements56Fe,24Mg + 20Ne + 28Si,20Ne + 21Ne + 22Ne + 16O,12C,16O, neutron capture line 2.2 MeV and continuum in the energy range of 0.3–0.6 MeV, are presented in Fig. 49.

During this flare the following maxima of the gamma-emission were observed [84] (maxima characteristics are presented in Table 3): at 20:42 UT (in the ranges corresponding to the continuum and the lines of56Fe,24Mg + 20Ne + 28Si,12C), at 20:43 UT (for the continuum and line of 12C), at 20:48 UT (in lines of 56Fe, n,12C and 16O), and at 20:52 UT (in lines of24Mg + 20Ne + 28Si, n,20Ne + 21Ne + 22Ne + 16O). Maximum at 20:45 UT was observed in all energy bands, except ones corresponding to the continuum and the line of20Ne + 21Ne + 22Ne + 16O. Maxima at 20:46 UT and at 20:51 UT were observed in the ranges of all lines, except the line20Ne + 21Ne + 22Ne + 16O. Maximum at 20:49 UT corresponding to maximum emission in the soft X-band according to the data of the GOES-12 satellite was not registered in the energy band E  > 0. 1 MeV [78], but maximum at 20:48 UT corresponded to maximum of X-rays in the range of 12–25 keV observed by the RHESSI instrument (http://hesperia.gsfc.nasa.gov/hessidata/dbase/).

Fig. 50

Examples of periodograms for AVS-F counts rate temporal profiles during the solar flare of October 29, 2003, in energy bands corresponding to carbon (a), oxygen (b), and neutron capture lines (c). From [16]

The October 29, 2003, solar flare emission in the low-energy gamma-band of the AVS-F apparatus was registered during approximately 1000 s, and it allowed to analyze periodograms for temporal profiles with time resolution of 16 s, including energy ranges corresponding to the identified spectral lines and continuum. Examples of periodograms for this solar flare temporal profiles in the energy ranges corresponding to the continuum, neutron capture line, carbon and oxygen lines are presented in Fig. 50. Periodograms analysis allows to make conclusion about the presence of thin structure with timescale varied from 34 to 158 s on this solar flare temporal profiles at significance level of 99 % in various energy ranges (Table 4) [16].

Several maxima were identified on the January 20, 2005, flare temporal profiles (see Fig. 51a). Two maxima at 06:44:36 UT and at 06:53:46 UT were coinciding in the statistic errors limits in the energy ranges of 0.15–0.30 MeV and 0.4–0.7 MeV (corresponded to the continuum and the combination of α α- and annihilation lines). One maximum at 06:46:36 UT was revealed in the ranges of 3.2–5.0 MeV and 5.3–6.9 MeV (22Ne + 16O + 12C and 16O), and one more at 06:47:16 UT in the band of 1.7–2.3 MeV (nuclear lines of24Mg + 20Ne + 28Si and neutron capture line) (see Fig. 51a). Analysis of the corresponding periodograms had shown the presence of thin structure with timescale of 33–92 s on these temporal profiles in discussed above energy ranges at the significance level of 99 % [32, 34] (see Table 5 and Fig. 51b, c).

Table 4

October 29, 2003, solar flare counts rate temporal profiles characteristic timescales in the various energy ranges according to AVS-F apparatus data

Range

   

limits,

   

MeV

Interpretation

Temporal profiles characteristic timescales, s

 

300–600

​continuum​

​100​

39

 

​0.81–0.94​

Fe

​158​

​100​

46

 

​1.51–1.74​

​Mg+Ne+Si​

​138​

​100​

85

69

58

48

34

 

​2.14–2.44​

n

​158​

​110​

39

 

​2.6–3.4​

Ne+O

​158​

​138​

74

55

 

​4.0–5.0​

C

​158​

​123​

​110​

69

58

46

 

​5.3–6.9​

O

​158​

78

55

39

 

The following general maxima were revealed in the January 17, 2005, flare temporal profiles registered in the ranges corresponding to the identified spectral features: 09:41:26 UT (0.15–0.30 MeV—continuum), 09:40:36 UT (0.4–0.7 MeV—α α + annihilation line), 09:42:31 (0.7–0.9 MeV—56Fe), 09:42:16 (2.0–2.3 MeV—24Mg + 20Ne + 28Si + neutron capture line), and 09:41:54 (3.6–5.0 MeV—12C). These temporal profiles had thin structure with time scale of 33–61 s at the significance level of 99 %, and it was proved by the analysis of corresponding periodograms—see Table 5 and Fig. 52 [32, 34].

January 15, 2005, flare temporal profile had one maximum at 23:00:19 UT in the range corresponding to the continuum, maximum at 23:00:45 UT in two other ranges (0.48–0.67 MeV—positron line and 2.0–2.3 MeV—neutron capture line). Also thin structure with time scale of 34–87 s was observed for all this flare temporal profiles at the significance level of 99 %—see Table 5 and Fig. 53 [32, 34].

Fig. 51

Temporal profiles of the January 20, 2005 solar flare (flare’s begin was at 06:33:26.222) in the energy ranges corresponding to the separated spectral features (a), their periodograms (b), and characteristic time scales for temporal profiles of this event (c). Beginning of time interval when the CORONAS-F satellite passed through the Earth’s radiation belt is marked by the arrow RB. From [32]

Integral temporal profiles with time discretization of 1 ms in the low-energy range of the AVS-F apparatus (from one to six intervals 4.096 s long for each flare depending on its duration) were analyzed for seven solar flares. According to the results of the preliminary analysis no time regularities with duration from 2 up to 100 ms at the 99 % significance level were registered on temporal profiles of the flares of July 17, 2002 (M8.5 class), April 4, 2002 (M6.1 class), October 26, 2003 (M7.6 class), November 4, 2003 (first short episode), and September 12, 2004 (M3.2 class) [18]. A fragment of the November 4, 2003, solar flare temporal profile with time discretization of 1 ms in the energy range of 0.1–17 MeV began at 19:33:20,346 UT is presented in Fig. 54a. Periodogram for this temporal profile is shown in Fig. 54b.

As it was already mentioned in the present section, summarized temporal profile of the flare of October 29, 2003 (X10 class) had complicated structure in the energy range of 0.1–17 MeV and in the energy ranges corresponding to the features identified in this flare energy spectrum. However in all six fragments of this flare integral temporal profiles with time discretization of 1 ms thin
Table 5

Characteristic timescales of temporal profiles thin structure of the solar flares observed by the AVS-F apparatus in January 2005

 

20.01

15.01

17.01

 

E, MeV

​0.4–0.7​

​2.0–2.3​

​3.2–5.0​

​5.3–6.9​

​0.4–0.7​

​2.0–2.3​

​2.0–2.3​

​3.6–5.0​

​0.7–0.9​

​0.4–0.7​

 

τ, s

83

69

92

92

61

87

61

64

61

61

 
 

64

52

46

59

47

34

46

35

46

37

 
 

49

44

42

44

41

33

33

 
 

44

40

36

38

34

 
 

38

35

 
 

33

 
structure with time scale of 2–100 ms was absent at the significance level of 99 % [16]— see Fig. 55.

Summarized temporal profile of the January 20, 2005 flare (X7.1 class) had simple structure in the energy range of 0.1–20 MeV, but thin structure with time scale of 33–92 s was observed in its temporal profiles in the energy ranges corresponding to the features identified in the energy spectrum. A fragment of this flare integral temporal profile with time discretization of 1 ms in the range of 0.1–20 MeV is presented in Fig. 56a, and its periodogram in Fig. 56b. Data analysis had shown the presence of time regularities with the timescales of 7 ms, 8 ms, 22 ms, and 35 ms—see Fig. 56. The structure of these time regularities remained the same after averaging of this temporal profile over 2 s—corresponding periodogram is presented in Fig. 56a. Thus, thin structure with characteristic scales of 7–35 ms was observed on this flare integral temporal profile with time discretization of 1 ms in the energy range of 0.1–20 MeV at the confidence level of 99 % [32, 33].

Hard X-Ray and Gamma-Emission During Faint Solar Flares

As it was mentioned above, the AVS-F apparatus registered emission with energy of E > 50 keV during several faint solar flashes (of B and C classes according to the GOES classification) [85].

Fig. 52

Temporal profiles for the flare of January 17, 2005 (beginning at 09:37:06.402) in the energy ranges corresponding to the separated spectral features (a), their periodograms (b), and characteristic time scales for temporal profiles of this flare (c). Beginning of time interval when the CORONAS-F satellite passed through the Earth’s radiation belt is marked by the arrow RB. From [32]

Fig. 53

Temporal profiles of the January 15, 2005 solar flare (flare’s begin was at 22:45:04.576) in the energy ranges corresponding to the separated spectral features (a), their periodograms (b), and characteristic time scales for temporal profiles of the this flare (c). Time intervals when the CORONAS-F satellite passed through the Earth’s radiation belt are marked by the arrows RB. From [32]

Fig. 54

Fragment of AVS-F counts rate temporal profile in energy range of 0.1–17 MeV during the flare of November 4, 2003 with time resolution of 1 ms in the time interval from 19:33:20.346 UT till 19:33:24.443 UT (a) and its periodogram (b). From [16]

Fig. 55

Fragment of temporal profile (a) of the AVS-F counts rate in the energy range of 0.1–17 MeV during the flare of October 29, 2003, with time resolution of 1 ms in the time interval from 20:41:48.789 UT till 20:41:52.886 UT and its periodogram (b). From [16]

Fig. 56

Fragment of AVS-F counts rate temporal profile of January 20, 2005, solar flare with time resolution of 1 ms in the time interval from 06:53:59.933 UT till 06:54:04.030 UT (a), its periodogram (b), and periodogram of this temporal profile averaged over 2 ms (c). From [32]

Fig. 57

January 12, 2005, solar flare (B4.6 class) temporal profiles of the AVS-F counts rate (with background subtraction) in energy region of 0.1–7 MeV and one of the X-ray flux by the GOES-12 satellite data in the band of 0.1–0.8 nm. From [85]

Fig. 58

January 12, 2005 (B4.6 class) solar flare energy spectrum according to the AVS-F apparatus data (with background subtraction) in the low-energy γ-band during time interval 20:09–20:14 UT. From [85]

Fig. 59

January 14, 2005 (C2.5 class) solar flare temporal profiles of the AVS-F counts rate in energy band of 0.1–0.6 MeV (with background subtraction) and one of X-ray flux by the GOES-12 satellite data in the band of 0.1–0.8 nm. From [85]

Fig. 60

January 14, 2005 (C2.5 class) solar flare energy spectrum according to the AVS-F data in the low-energy γ-band during time interval 17:35-17-40 UT (with background subtraction). From [85]

The results of the AVS-F apparatus database analysis had shown that the existence of the component with energy E > 50 keV does not depend on the flare class in the soft X-range of 0.5–10 keV. Thus, for some flares of M class no statistically significant counts rate increase over the background in the range of E > 50 keV were detected by the AVS-F apparatus. Such flares typical example was the event of November 8, 2001, of M4.2 class (beginning at 14:59 UT, maximum at 15:35 UT, end at 16:00 UT according to the detectors on board the GOES series satellites data; http://www.swpc.noaa.gov/ftpdir/warehouse/2001/2001_events.tar.gz). However in some cases the emission in the low-energy gamma-band was observed during very faint solar flares (of B and C classes), for instance during the events of January 12, 2005, and January 14, 2005.

I According to the GOES data the solar flare of January 12, 2005, of B4.6 class was observed from 20:08 UT till 20:13 UT, with maximum of the soft X-rays emission at 20:11 UT (http://www.swpc.noaa.gov/ftpdir/warehouse/2005/2005_events.tar.gz). During all this time period the AVS-F apparatus registered significant gamma-emission increase over the background level in the low-energy gamma-range—see Fig. 57.

Moreover according to the results of the preliminary analysis thin structure with characteristic timescale of ∼ 90 s was observed on this flare temporal profile of the AVS-F apparatus low-energy gamma-band. Maximum energy of γ-quanta detected during this flare was \(E_{\mathrm{max}} = 7.0 \pm 0.3\) MeV. Energy spectrum of the flare of January 12, 2005, is presented in Fig. 58. At the level of significance of 97 % this spectrum was approximated by power function with the index of \(\alpha = -1.5 \pm 0.1\). There were no lines in energy spectrum of this flare, i.e., it was e-dominant. Unfortunately, there were no data of the RHESSI satellite during this flare because of telemetry gap and spacecraft passing through the radiation belt (http://sprg.ssl.berkeley.edu/tohban/browser/?show=grth+qlpcr).

According to the data of the detectors on board the GOES series satellites C2.8 class solar flare of January 14, 2005, lasted from 17:35 UT till 17:50 UT with maximum of the soft X-ray emission at 17:42 UT (http://www.swpc.noaa.gov/ftpdir/warehouse/2005/2005_events.tar.gz). During this flare the statistically significant count rate exceeding over the background level in the low-energy range of the AVS-F apparatus was detected in time interval of 17:35–17:40 UT at the phase of the soft X-ray rise. Temporal profiles of this flare in the low-energy AVS-F apparatus gamma-band and according to the data of GOES-12 are presented in Fig. 59. Maximum energy of γ-quanta registered during the flare of January 14, 2005, was Emax = 0. 64 ± 0. 03 MeV. Analogous to the January 12, 2005 solar flare no spectral lines were also identified in the energy spectrum of the flare of January 14, 2005—see Fig. 60. This flare was also of the e-dominant type, its energy spectrum during time interval of 17:35–17:40 UT was approximated by the power-function with the index of \(\alpha = -3.1 \pm 0.2\).

Solar flare March 6, 2005, with class B1.1 was the faintest event for which emission in the energy band E > 0. 1 MeV was registered by AVS-F data on the results of preliminary analysis [38].

Up to now the subset of 60 solar flares with classes B and C by GOES classification with the presence of statistically significant flux in energy band E > 0. 1 MeV was studied by the data of AVS-F apparatus on board CORONAS-F satellite. The results of faint flares high-energy γ-emission analysis were discussed in detail in [38]. The shapes of temporal profiles on GOES and AVS-F/ XSS-1 data were similar at (90–99) % confidence level. Moreover, the maxima of the time derivatives of temporal profiles on GOES and AVS-F/ XSS-1 data were observed in the same time moments.

Only about 50 % of the processed faint solar flares (classes B and C on GOES classification) for which statistically significant flux in energy band E > 0. 1 MeV was registered correspond to Neupert effect according to AVS-F data [38, 85]. Discordance of behavior of hard X-ray and γ-emission temporal profiles and time derivative of soft X-ray emission temporal profiles during faint solar flares can indicate that in such flares occurs additional particles acceleration or dissipation of their energy, for example, due to turbulence [38].

Some thin structure with characteristic timescale 50–110 s was observed on temporal profiles of several faint events, for example on January 7 and 12, 2005 flares (classes B2.3 and B4.6 correspondingly) and on March 5, 2005 one (class B2.0) [38, 39, 85]

Energy spectra of all such solar flares had power law shape without any features by results of preliminary data analysis [38, 39].

During some faint flares high energy γ-emission was observed. For example, γ-quanta with energy up to several tens of MeV were registered during limb flare January 7, 2005 [39] and up to several MeV during disk one January 12, 2005 [38]. During these flares Neupert effect was not observed [38].

Hard X-rays emission in the range from 40 keV up to several hundreds of keV was also detected during several flares of > C7.7 class (http://smdc.sinp.msu.ru/index.py?nav=flares) in SCR experiment on board the CORONAS-F satellite (see the chapter “Scientific Set of Instruments “Solar Cosmic Rays””). The cataloging of faint solar flares (B, C classes according to the GOES classification) basing on the AVS-F apparatus data now is still in progress.

Catalogue of Solar Flares in the High-Energy Gamma-Band According to the Data of the AVS-F Apparatus On board the CORONAS-F Satellite During 2001–2005

About one-fourth part of the solar flares registered by the AVS-F apparatus in the low-energy gamma-band during the period from August 2001 till December 2005 were accompanied by emission in the high-energy γ-band [16, 29, 32, 33].

The solar flare of October 29, 2003, is a typical example of this phenomenon. Duration of its γ-emission in both gamma-ranges of the AVS-F apparatus almost coincides with the duration of soft X-rays emission [16]. But as it was mentioned in the previous section the temporal profiles of the flare in both γ-bands have more complicated structure than in the soft X-ray band—see Fig. 43.

Solar flare of January 20, 2005 (X7.1 class) was also observed in both ranges of the AVS-F apparatus. Gamma-emission of this flare in both low-energy and high-energy ranges of the AVS-F apparatus was observed during the rise of the emission in the soft X-range. As it was mentioned in the previous section, it was accompanied by proton event and GLE (the most intensive [43, 48, 87, 99] for the last 27 and 49 years, respectively, although there were more powerful flares during these time intervals) and by CME. This flare gamma-emission temporal profiles (integration time of 16 s in the range of 0.1–20 MeV and 128 s in the range of 2–260 MeV) according to the data of the AVS-F had simple structure with one maximum as in the soft X-range [29, 32, 33] (Fig. 61).

Fig. 61

Temporal profiles of the AVS-F counts rate (with background subtraction) during the flare of January 20, 2005, in the energy range of 0.1–20 MeV and 2–140 MeV and X-ray flux in the band of 0.1–0.8 nm according to the data of the GOES-12 satellite. The moment when the CORONAS-F satellite went into the Earth’s radiation belt is marked with an arrow RB. From [35]

Fig. 62

AVS-F counts rate temporal profiles during the flare of January 20, 2005, in energy bands: (a) 2–10 MeV, 15–21 MeV, 30–110 MeV, 60–80 MeV, and 140–260 MeV (without background subtraction); (b) 2–10 MeV (corresponding to registration of nuclear lines and neutron capture line), 15–21 MeV and one corresponding to gamma-rays from neutral pions decay (total range of 30–110 MeV and region of 60–80 MeV) (with background subtraction). From [26]

Fig. 63

Two-dimensional distribution of the ratio of the slow light output component to the total light output dependence on the total energy deposition in the SONG-D detector (a) and energy spectrum (with background subtraction) in the high-energy gamma-band obtained by convolution of this distribution by the axis corresponding to the ratio of the slow light output component to the total light output (b) according to the data of the AVS-F apparatus for January 20, 2005, solar flare summarized during time interval 06:44:52.351–06:51:15.795 UT. From [35]

Hard gamma-emission temporal profiles registered by the AVS-F apparatus during this flare without background subtraction are presented in Fig. 62a. Maximum energy of γ-quanta detected during the event of January 20, 2005 was 137 ± 4 MeV—in the energy range of 140–260 MeV the counts rate did not exceed the background level in the statistical errors limits [29]. January 20, 2005, solar flare hard gamma-emission temporal profiles (with background subtraction) are presented in Fig. 62b. During this flare the hard gamma-emission was observed in the range corresponding to the registration of gamma-quanta from neutral pions decays [26, 29].

Summarized two-dimensional distribution of the ratio of the slow light output component to the total light output in dependence on the total energy deposition in the CsI(Tl) for this flare in time interval from 06:44:52,351 UT till 06:51:15,795 UT with background subtraction is presented in Fig. 63a. Data analysis has shown that during maximum of the flare of January 20, 2005, hard gamma-emission registration the neutrons and relativistic protons fluxes did not exceed background level in the statistical errors limits, powerful proton event, and GLE were detected later [48, 87]. According to the data of the neutron monitors “SOUTH POLE” (90 S) and “Inuvik” (68. 4 N 133. 7 W) the counts rate rises were registered at 06:53:30 UT and at 07:05:30 UT, respectively [48, 99].

The maximum in the region of 1–6 channels of the abscissas axis corresponds to the sum of nuclear lines in the range of 2–7 MeV and to neutron capture line of 2.2 MeV (for more details see Fig. 46), and one in the region of 30–50 channels associated with registration of gamma-emission from the neutral pions decay [26]. In the region of 16–20 channels one more feature were identified. All this features are also seen in this flare energy spectrum—see Fig. 63b: wide line in the region of 2–7 MeV, corresponding to registered in the low-energy gamma-band nuclear lines and the line from neutron capture, and wide spectral feature caused by gamma-quanta from neutral pions decay [26, 29]. At the significance level of 2. 5σ new non-identified spectral feature were detected in the range of 15–21 MeV [26]. But in energy spectrum registered in the maximum of high-energy gamma emission of the January 20, 2005 flare (06:47:00–06:49:08 UT) this feature was identified at the significance level of 3σ.

Spectral feature from neutral pions decay was registered earlier during several solar flares in other experiments (for instance, see [57]). The feature in the range of 15–21 MeV can be the line of 15.11 MeV (12C + 16O), or a line 20.58 MeV from radiative neutron capture by3He, or their combination. The possibility of 15.11 MeV line detection was discussed in [51, 52], the 20.58 MeV one was only theoretically predicted in some articles (for instance, see [80, 81, 106]). Such feature in the solar flare energy spectrum was observed first time by the AVS-F apparatus [26].

Fig. 64

Temporal profiles of γ-emission for the flare of August 24, 2002, according to the data of the AVS-F apparatus and X-rays according to the data of the GOES-12 satellite. Time intervals when the CORONAS-F satellite was passing through the Earth’s radiation belt are marked with arrows RB. From [29]

The class X3.1 solar flare of August 24, 2002, was observed by the detectors on board the GOES-12 satellite in the range of 0.1–0.8 nm during the time interval of 00:49–01:31 UT, maximum of emission was registered at 01:12 UT (http://www.swpc.noaa.gov/ftpdir/warehouse/2002/2002_events.tar.gz). It originated from the active region 10069. During the flare of August 24, 2002, two episodes of gamma-emission in the AVS-F apparatus low-energy range were detected (00:57:00–01:06:16 UT and 01:15:46–01:24:02 UT) [18], but γ-emission in the range of 10–94 MeV was observed only during the second episode of its registration in the low-energy range [29] at the decreasing of emission in the soft X-band according to the data of the detectors on board GOES-12 satellite (see Fig. 64). At the end of the first episode of this flare γ-emission registration the CORONAS-F satellite went into the radiation belt, and the second episode was registered during the spacecraft passing of the polar cap. One more feature of this flare was the presence of thin structure with characteristic timescale of ∼ 60 s in the summarized temporal profile of the second episode of the flare in the AVS-F apparatus low-energy range [29]. It must be noted that this flare temporal profiles shapes differ essentially in the low- and high-energy ranges [18, 29].

Presence or absence of high-energy γ-emission during the solar flare do not depend on intensity of its intensity in the soft X-range [18, 29]: the flares of December 30, 2004 (M4.2) and January 20, 2005 (X7.1) were registered by the AVS-F apparatus both in the low- and the high-energy γ-ranges while the counts rate in the high-energy range did not exceed background level for a statistically significant value during the flares of January 17, 2005 (X3.8) and January 15, 2005 (X2.6), although they were observed by the AVS-F apparatus in the low-energy range [18].

Conclusions

The whole volume of the AVS-F experiment available database is 20315 files (orbits 88–24570) contains 1 266 657 740 Bytes of information. The averaged percent of telemertry gaps was about 0.02 % per file.

In-flight calibration of the AVS-F apparatus was done both in the high-energy and in the low-energy gamma-ranges. The areas corresponding to registration of γ-quanta, relativistic protons, and secondary particles produced via neutrons interactions (including non-relativistic protons and α-particles) were determined on two-dimensional distributions of the dependence of the ratio of the slow light output component to the total light output on the total energy deposition in the SONG-D detector. Operation of the spectrometry channel of the AVS-F apparatus was stable during all period the experiment was conducted, threshold energy and conversion coefficient were changed for ∼ 1 % and ∼ 1. 8 % per month correspondingly. The obtained calibration information was used for the development of the NATALYA-2M instrument on board CORONAS-FOTON satellite [79] operated from January 31, 2009 to December 3, 2009.

Analysis of the background conditions allowed to make the AVS-F apparatus background model: in each spectral channel of γ-bands background counts rate temporal profile was approximated by the forth- or fifth-degree polynomials at the equatorial satellite’s orbit segments and by the parabolic curve, linear function or by a constant in the polar regions. Such approximations were made in the concrete geomagnetic activity level (the values of Kp and Dst indices were taken into account). This approximation was used for identification of the burst events, study of their characteristics, and software development for the data analysis in the experiments on board CORONAS-PHOTON satellite [77].

At present over 1,100 events with duration more than 2 s without any coordinate relations to Earth Radiation Belts and South Atlantic Anomaly were separated on the results of preliminary analysis of AVS-F experiment database:

  1. 1.

    About 68 % of the identified events were associated with quasistationary equatorial precipitations—on some equatorial segments in the ranges of geographic latitude of \(-2{5}^{\circ }\div +3{0}^{\circ }\) there were discovered 15–30 % counts rate increases in the low-energy gamma-band of the AVS-F apparatus over its average value obtained by approximation of these parts with polynomials.

    Four basic types of quasistationary precipitations were identified. For the precipitations with fast counts rate rise toward North and slow decrease toward South from geomagnetic equator in the latitudinal profiles (21 % of the registered precipitations—II type) the amount of the observed precipitations linearly depends on the geomagnetic activity level at 95 % significance level. For quasistationary precipitations with counts rate fast rise toward South and slow decrease toward North from geomagnetic equator (about 44 %—I type) analogous tendency was observed. The samples of the events of III type ( ∼ 4 %, latitudinal profiles were symmetric with sharp boundaries) and of IV type (also  ∼ 4 %, latitudinal profiles were symmetric and have sharp maximum) are still not enough for the statistical analysis.

    The precipitations of I–III types were mainly located symmetrically relatively to geomagnetic equator as a band about 40 wide, width of the near-equator region where IV type precipitations were observed was about ∼ 20. So, the main part of the precipitations was located in the regions of the low-latitudinal (L ∼ 1. 5) and equatorial electrons precipitations were observed. Quasistationary equatorial precipitations can be associated with charged particles precipitations in certain parts of the Earth’s magnetosphere were regularly crossed by the CORONAS-F spacecraft.

     
  2. 2.

    About 7 % of the detected events were solar flares with classes stronger than M1.0 according to the GOES classification. Catalogues of solar flares detected in the low- and high-energy gamma-ranges of the AVS-F apparatus operation were made. Solar flares hard X-rays and γ-emission were mainly observed during the rise or maximum phases of the emission in the soft X-rays band according to the detectors on board the GOES series satellites data and duration of their registration is less than of the soft X-rays band. For some solar flares duration of the hard X-rays and γ-emission almost coincides with the duration of the emission in the soft X-rays band. There was also registered several flares during which the AVS-F apparatus detected more than one episode of hard X-rays and γ-emission, but in the intervals between detected episodes the count rate intensity did not exceed background level for a statistically significant value.

    According to the preliminary data analysis gamma-emission with energy over 10 MeV was registered during 12 % of the observed flares with classes stronger than M1.0. During all flares except one of August 24, 2002, the duration of γ-emission in both AVS-F apparatus gamma-ranges substantially coincides. Presence or absence of high-energy γ-emission during the solar flare does not depend on its intensity in X-range.

    In the spectra of some solar flares stronger than M1.0 in the low-energy gamma-range several spectral lines complexes were observed. Registered corresponded to α α-lines, annihilation line, nuclear lines, neutron capture line on1H (2.223 MeV). In the high-energy range there were detected spectral features corresponded to the combination of the observed in the low-energy range nuclear and neutron capture on1H lines (in the band of 2–7 MeV) and the one caused by the registration of gamma-quanta from neutral pions decay. In the spectrum of the January 20, 2005 solar flare the feature in the range of 15–21 MeV was detected for the first time. It can be associated with lines of 15.11 MeV (12C + 16O) or 20.58 MeV (from neutron radiative capture on3He), or with their combination.

    Energy spectra of several solar flares observed by the AVS-F apparatus were not contained any gamma-lines, i.e., these flares were e-dominant [11, 14, 18]. Previously flares of this type were registered by various detectors, in particular, by the SMM/GRS [103].

    Thin structure with characteristic timescale of 30–160 s was observed at 99 % significance level on some solar flares stronger than M1.0 temporal profiles in the low-energy gamma-band in the energy ranges corresponding to the identified spectral features or whole gamma-band energy boundaries. The fragments of integral temporal profiles with time discretization of 1 ms and duration of 4.096 s in the low-energy AVS-F apparatus gamma-range for seven solar flares were analyzed (from 1 to 6 fragments for each flare). According to the results of the preliminary analysis only during the flare of January 20, 2005, thin structure with timescale from 7 ms to 35 ms was detected at 99 % confidence level in the energy range of 0.1–20 MeV.

    During faint solar flares (of B and C classes according to the GOES classification) the emission in the energy band E > 100 keV was registered from ∼ 60 solar flares and from several ones γ–quanta with energy up to several tens of MeV were observed [38]. Such emission was detected either at the phase of rise phase of the soft X-rays emission, or during all its duration [38, 39, 84]. The results of faint flares high-energy γ-emission analysis were discussed in detail in [38]. The shapes of temporal profiles on GOES and AVS-F/XSS-1 data were similar at (90–99) % confidence level and the maxima of the time derivatives of temporal profiles on GOES and AVS-F/XSS-1 data were observed in the same time moments. Some thin structure with characteristic timescale 50–110 s was observed on temporal profiles of several faint events [38, 39]. There were no lines in these solar flares spectra, i.e., such events are e-dominant. Now a catalogue of such solar flares is composed.

     
  3. 3.

    About 3 % of the identified events were gamma-ray bursts. The most part of GRBs detected in the low-energy range of the AVS-F apparatus were confirmed by the data of the HETE, RHESSI, and SWIFT/BAT experiments, and during some bursts high-energy gamma-emission was observed: Emax = 147 ± 3 MeV for GRB050525 [25, 36]. During the discussed time period only the SONG-D detector could provide registration of so high energy γ–emission.

     
  4. 4.

    About 22 % of the identified events are needed to be analyzed in more detail.

     

About 17 % of all detected events (excluding solar flares) were observed in the Earth’s shadow.

Several short events with duration of 1–16 ms were registered during the experiment. They were associated with terrestrial gamma-ray flashes. These events were detected above the powerful thunderstorm formations.

Basing on the results of the data analysis during the whole period of the AVS-F apparatus operation it is possible to conclude that the AVS-F apparatus was operated in normal mode without degradation of its dynamical characteristics up to the end of the CORONAS-F operation on December 6, 2005.

Footnotes

  1. 1.

    Deceased

  2. 2.
    At spectrum multiplying on a power-law function of the r-th order at r > 0 shift of the line center was taken into account. This shift was calculated by the following equation:
    $$\displaystyle{ x = x_{0}/2 + \sqrt{{(x_{0 } /2)}^{2 } + {r\sigma }^{2}} }$$
    (2)
    for the features which can be approximated with a gaussian with the parameters x0 and σ.

References

  1. 1.
    Alcaraz, J., Alpat, B., Ambrosi, G., Anderhub, H., et al.: Cosmic protons. Phys. Lett. B490, 27 (2000)ADSGoogle Scholar
  2. 2.
    Alcaraz, J., Alvisi, D., Alpat, B., Ambrosi, G., et al.: Protons in near earth orbit. Phys. Lett. B472, 215 (2000)ADSCrossRefGoogle Scholar
  3. 3.
    Arkhangelskaja, I.V.: Application of fractal analysis for the processing of temporal profiles of non-stationary event recorded by the AVS-F instrument during the experiment onboard the spacecraft CORONAS-F. Kosmicheskaya nauka i tekhnologiya 9(5–6), 81 (2003), Ukraine (in Russian)Google Scholar
  4. 4.
    Arkhangelskaja, I.V.: CORONAS-F/AVS-F observations of terrestrial gamma-ray flashes. In: AGU, 86(52), Fall Meet. Suppl., Abstract N AE14A-08.2005Google Scholar
  5. 5.
    Arkhangelskaja, I.V., Arkhangelsky, A.I., Kotov, Yu.D.: Model of the background of the AVS-F instrument in the low-energy gamma-range. Proceedings “Scienific session of MEPhI-2005”, M.: MEPhI, vol. 7, p. 35 (2005) (in Russian)Google Scholar
  6. 6.
    Arkhangelskaya, I.V., Chervyakova, O.I., Arlhangelsky, A.I., Glyanenko, A.S., Kotov, Yu.D.: Analysis of the stable operation of sectrometry channel of the AVS-F instrument in the low-energy gamma-range. In: Proceedings of the “International Conference “CORONAS-F: Three Years of the Solar Activity Observations, 2001–2004” January 31–February 5, IZMIRAN, Troitks, p. 33. (in Russian) (2005)Google Scholar
  7. 7.
    Arkhangelsky, A.I., Glyanenko, A.S., Kotov, Yu.D., Pavlov, A.V., et al.: The AVS-F experiment of the CORONAS-F project on registration of fast-changing fluxes of cosmic and solar gamma-emission. Pribory i tekhnika eksperimenta (5), 16 (1999) (in Russian)Google Scholar
  8. 8.
    Arkhangelsky, A.I., Glyanenko, A.S., Kotov, Yu.D., Pavlov, A.V., et al.: Modernisation of the AVS-F experiment of the CORONAS-F project. In: Proceedings of the “Scientific Session MEPhI-1999”, vol. 4. M.: MEPhI, p. 30 (1999) (in Russian)Google Scholar
  9. 9.
    Arkhangelskaja, I.V., Arkhangelsky, A.I., Glyanenko, A.S., Kotov, Yu.D.: In-flight calibration and the resulst of the data processing for the AVS-F instrument obtained during the experiment onboard the CORONAS-F satellite. Kosmicheskaya nauka i tekhnologiya 9(2), 20 (2003), Ukraine. (in Russian)Google Scholar
  10. 10.
    Arkhangelskaja, I.V., Arkhangelsky, A.I., Glyanenko, A.S., Kotov, Yu.D., et al.: October 29, 2003 solar flare gamma-emission spectra investigation by SONG and AVS-F data onboard CORONAS-F satellite. In: Procedings of the “Scientific Session MEPhI-2004”, M.: MEPhI, vol. 7, p. 18 (in Russian) (2004)Google Scholar
  11. 11.
    Arkhangelsky, A.I., Arkhangelskaja, I.V., Kotov, Yu.D., Glyanenko, A.S., et al.: Solar flares observed by AVS-F instrument onboard CORONAS-F satellite during 2,5 year of it’s operation. In: Multi-Wavelength Investigations of Solar Activity, IAU Symposium, vol. 223, p. 441. Cambridge University Press, Cambridge (2004)Google Scholar
  12. 12.
    Arkhangelskaja, I.V., Arkhangelsky, A.I., Kotov, Yu.D., Kuznetsov, S.N.: The investigation of the spectra of solar events observed in October–November 2003. Multi-Wavelength Investigations of Solar Activity, IAU Symposium, vol. 223, p. 439. Cambridge University Press, Cambridge (2004)Google Scholar
  13. 13.
    Arkhangelskaja, I.V., Arkhangelsky, A.I., Glyanenko, A.S., Samoilenko, V.T., et al.: The stability of the AVS-F apparatus spectrometric section in the gamma-band. In: Proceedings of the 28th Russian Cosmic Ray Conference, p. 153 (2004)Google Scholar
  14. 14.
    Arkhangelskaja, I.V., Arkhangelskii, A.I., Glyanenko, A.S., Kotov, Yu.D., et al.: The solar flares observed in low energy gamma-ray band by AVS-F apparatus data onboard CORONAS-F satellite in 2001–2005 years. In: Danesy, D., Poedts, S., De Groof, A., Andries, J. (eds.) Proceedings of the 11th European Solar Physics Meeting “The Dynamic Sun: Challenges for Theory and Observations” (ESA SP-600), p. 108.1. 11–16 September 2005, Leuven, Belgium (2005)Google Scholar
  15. 15.
    Arkhangelskaja, I.V., Arkhangelskii, A.I., Glyanenko, A.S., Kotov, Yu.D., et al.: The investigation of January 2005 solar flares gamma-emission by AVS-F apparatus data onboard CORONAS-F satellite in 0,1–20 MeV energy band. In: Danesy, D., Poedts, S., De Groof, A., Andries, J. (eds.) Proceedings of the 11th European Solar Physics Meeting “The Dynamic Sun: Challenges for Theory and Observations” (ESA SP-600), p. 107.1. 11–16 September 2005, Leuven, Belgium (2005)Google Scholar
  16. 16.
    Arkhangelskaja, I.V., Arkhangelsky, A.I., Kotov, Yu.D., Kuznetsov, S.N., et al.: Gamma-ray radiation of solar flares in October-November 2003 according to the data obtained with the AVS-F instrument onboard the CORONAS-F satellite. Solar Syst. Res. 40(4), 302–313 (2006)ADSCrossRefGoogle Scholar
  17. 17.
    Arkhangelskaja, I.V., Arkhangelsky, A.I., Kotov, Yu.D.: The AVS-F apparatus background model in the low-energy γ-band. In: Proceedings of the “International Conference “CORONAS-F: Three Years of the Solar Activity Observations, 2001–2004” January 31–February 5, IZMIRAN, Troitks, p. 28 (in Russian) (2005)Google Scholar
  18. 18.
    Arkhangelskaja, I.V., Arkhangelsky, A.I., Kotov, Yu.D., Kuznetsov, S.N., et al.: The solar flare catalog in the low-energy gamma-ray range based on the AVS-F instrument data onboard the CORONAS-F satellite in 2001–2005. Solar Syst. Res. 40(2), 133 (2006)ADSCrossRefGoogle Scholar
  19. 19.
    Arkhangelskaja, I.V., Amandzholova, D.B., Arkhangelsky, A.I., Kotov, Yu.D.: The properties of the quasistationary equatorial precipitations according to the data of the AVS-F instrument onboard the CORONAS-F satellite. In: Abstracts of the “International Conference “CORONAS-F: Three Years of the Solar Activity Observations, 2001–2004” January 31–February 5, IZMIRAN, Troitsk, p. 14 (in Russian) (2005)Google Scholar
  20. 20.
    Arkhangelskaja, I.V., Amandzholova, D.B., Arkhangelsky, A.I., Kotov, Yu.D.: The stydies of quasistationary equatorial precipitaions according to the data of the AVS-F instrument. In: Procedings of the “Scientific Session MEPhI-2005”, M.: MEPhI, vol. 7, p. 31 (in Russian) (2005)Google Scholar
  21. 21.
    Arkhangelskaja, I.V., Amandzholova, D.B., Arkhangelsky, A.I., Kotov, Yu.D.: The studies of dependece of quasistationary equatorial precipitations on geomagnetic activity according to the data of the AVS-F instrument. In: Procedings of the “Scientific Session MEPhI-2007”, M.: MEPhI, vol. 7, p. 27 (in Russian) (2007)Google Scholar
  22. 22.
    Arkhangelskaja, I.V., Amandzholova, D.B., Arkhangelsky, A.I., Kotov, Yu.D.: Studies of the dependence of quasistationary equatorial precipitations on Kp- and Dst-indices of geomagnetic activity according to the data of the AVS-F instrument. In: Procedings of the “Scientific Session MEPhI-2006”, M.: MEPhI, vol. 7, p. 17 (in Russian) (2006)Google Scholar
  23. 23.
    Arkhangelskaja, I.V., Amandzholova, D.B., Arkhangelsky, A.I., Kotov, Yu.D.: Features of quasi-stationary precipitations according to the data obtained with the AVS-F instrument onboard the CORONAS-F satellite. Solar Syst. Res. 42(6), 536–542 (2008)ADSCrossRefGoogle Scholar
  24. 24.
    Amandzolova, D.B., Arkhangelskaja, I.V., Arkhangelskiy, A.I., Kotov, Yu.D., et al.: The analysis of quasistationary equatorial precipitations observation frequency dependence from the geomagnetical activity level. In: Proceedings of The 20th European Cosmic Ray Symposium in Lisbon, Portugal (2007) http://www.lip.pt/events/2006/ecrs/proc/ecrs06-s0-189.pdf
  25. 25.
    Arkhangelskaja, I.V., Arkhangelsky, A.I., Kotov, Yu.D., Kuznetsov, S.N., et al.: Gamma-ray bursts recorded in 2001–2005 by the AVS-F instrument onboard the CORONAS-F satellite in the low-energy gamma-ray range. Cosmic Res. 45(3), 261–264 (2007)ADSCrossRefGoogle Scholar
  26. 26.
    Arkhangelskaja, I.V., Arkhangelsky, A.I., Kotov, Yu.D., Kalmykov, P.A.: The studying of January 20, 2005 solar flare characteristics in the high energy gamma-band by AVS-F data. In: Procedings of the “Scientific Session MEPhI-2007”, M.: MEPhI, vol. 7, p. 19 (in Russian) (2007)Google Scholar
  27. 27.
    Arkhangelskaja, I.V., Afonina, I.V., Arkhangelskij, A.I., Borodina, E.A., et al.: Preliminary results of database treatment from AVS-F apparatus in energy range 0,1–11 MeV. In: Proceedings of the 18th European Cosmic Ray Symposium, Moscow, Russian (2002)Google Scholar
  28. 28.
    Arkhangelskaja, I.V., Chervyakova, O.I., Arkhangelsky, A.I., Kotov, Yu.D., et al.: The stability of the AVS-F apparatus spectrometric section in the gamma-band. In: Procedings of the “Scientific Session MEPhI-2005”, M.: MEPhI, vol. 7, p. 33 (in Russian) (2005)Google Scholar
  29. 29.
    Arkhangelskaja, I.V., Arkhangelsky, A.I., Kotov, Yu.D., Glyanenko, A.S., et al.: Solar flares catalogue in the high-energy γ-band by the data of the AVS-F apparatus onboard CORONAS-F satellite for the period of 2001–2005. In: Obridko, V.N., Zaitsev, V.V. (eds.) Proceedings of the Russian Conference “Experimental and Theoretical Investigations of Geliophysics Activity Forecasting Fundamentals”, pp. 9–14, Troitsk (in Russian) (2006)Google Scholar
  30. 30.
    Arkhangelsky, A.I., Glyanenko, A.S.: The use of the MicroPC in the AVS-F apparatus onboard CORONAS-F satellite. Modern Tekhnol. Automatization (3), 58 (in Russian) (2004)Google Scholar
  31. 31.
    Arkhangelskaja, I.V.: Fractal analysis method applicability to Terrestrial Gamma-Ray Flashes separation in database of AVS-F apparatus onboard CORONAS-F satellite. In: Fullekrug, M., Mareev, E.A., Rycroft, M.J. (eds.) Proceedings of the NATO Advanced Study Institute on “Sprites, Elves and Intense Lightning Discharges”, Corte, Corsica, 24–31 July 2004, Nato Science Series II: (closed), vol. 225, XVI, 399 p. Springer, 2006. p. 386Google Scholar
  32. 32.
    Arkhangelskaja, I.V., Arkhangelsky, A.I., Kotov, Yu.D., Glyanenko, A.S., et al.: January 2005 solar flares series gamma-emission temporal profiles investigation by the data of the AVS-F apparatus onboard CORONAS-F satellite. In: Obridko, V.N., Zaitsev, V.V. (eds.) Proceedings of the Russian Conference “Experimental and Theoretical Investigations of Geliophysics Activity Forecasting Fundamentals”, Troitsk, pp. 15–20 (in Russian) (2006)Google Scholar
  33. 33.
    Arkhangelskaja, I.V., Arkhangelsky, A.I., Kotov, Yu.D., Kuznetsov, S.N., et al.: Gamma-ray emission from solar flares of January 2005 observed by the AVS-F apparatus onboard the CORONAS-F satellite. Solar Syst. Res. 42(4), 351–358 (2008)ADSCrossRefGoogle Scholar
  34. 34.
    Arkhangelskaja, I.V., Arkhangelskij, A.I., Glyanenko, A.S., Kotov, Yu.D.: Thin structure of temporal profiles of solar flares January 15, 17 and 20, 2005 by data of AVS-F apparatus onboard CORONAS-F satellite. Adv. Space Res. 43(4), 542–546 (2009)ADSCrossRefGoogle Scholar
  35. 35.
    Arkhangelskij, A.I., Arkhangelskaja, I.V., Glyanenko, A.S., Kotov, Yu.D.: AVS-F observations of gamma-ray emission during January 20, 2005 solar flare up to 140 MeV. Adv. Space Res. 43(4), 589–593 (2009)ADSCrossRefGoogle Scholar
  36. 36.
    Arkhangelskaya, I.V., Arkhangelskii, A.I., Glyanenko, A.S., Kotov, Yu.D., et al.: The GRB detected in low energy gamma-ray band by AVS-F apparatus onboard CORONAS-F satellite in 2001–2005 years. In: Kleinert, H., Jantzen, R.D., Ruffini, R. (eds.) Proceedings of the Eleventh Marcel Grossmann Meeting on General Relativity, pp. 2015–2018. World Scientific, Singapore (2008)Google Scholar
  37. 37.
    Arkhangelskaya, I.V., Arkhangelskii, A.I., Kotov, Yu.D. Kuznetsov S.N., et al.: Gamma-ray bursts observed by AVS-F apparatus onboard CORONAS-F satellite in the low-energy gamma-band during the period 2001–2005. 29 Russian Cosmic Ray Conference, Proceedings, pp. 2015–2018, GA11 (2006)Google Scholar
  38. 38.
    Arkhangelskaja, I., Arkhangelskiy, A., Kotov, Y., et al.: The emission in the region E > 0:1 MeV during disk and limb faint solar flares. Adv. Space Res. 51, 1996 (2013)CrossRefGoogle Scholar
  39. 39.
    Arkhangelskaja, I.V., Kostina, M.S., Arkhangelsky, A.I., et al.: Faint solar flares with hard X-ray and gamma emission observed by AVS-F onboard CORONAS-F satellite. In: Proceedings of the 37th COSPAR Scientific Assembly, Canada, p. 121 (2008)Google Scholar
  40. 40.
    Avakyan, S.V., Vdovin, V.I., Pustornakov, V.F.: Ionizing and penetrating radiaiton in the near-Earth space. SPb, Gosgidromet. (in Russian) (1994)Google Scholar
  41. 41.
    Barashenkov, V.S., Toneev, V.D.: Interactions of high-energy particles and atomic nuclei with nuclei. M.: Atomizdat, 1972. (in Russian)Google Scholar
  42. 42.
    Belousova, I.V., Bogovalov, S.V., Glyanenko, A.S., Klepikov, V.Yu. et al.: Background conditions in the range from 30 keV to 5 MeV in the orbit of CORONAS satellites. J. Moscow Phys. Soc. (6), 415 (1996)Google Scholar
  43. 43.
    Bieber, J.W., Clem, J., Evenson, P., et al.: Largest GLE in half a century: neutron monitor observations of the January 20, 2005 event. In: Acharya, B.S., Gupta, S., Jagadeesan, P., et al. (eds.) Proceedings of the 29th International Cosmic Ray Conference. 3–10 August 2005, Pune, India, vol. 1, p. 237. Tata Institute of Fundamental research, Mumbai (2005)Google Scholar
  44. 44.
    Bogovalov, S.V., Glyanenko, A.S., Grigoriev, A.I., Zhuravlev, V.I., et al.: Persectives of the studies of fast-changing X-ray and gamma-emission of the Sun by the CORONAS-I experiment. In: Proceedings of the III International Meeting CORONAS-I, Kaluga-88, L.: LPhTI, p. 130 (1989) (in Russian)Google Scholar
  45. 45.
    Bogomolov, A.V., Bogomolov, V.V., Denisov, Yu.I., Kudryavtsev, M.I., et al.: Characteristics of the components of the background gamma-emission and neutrons on the “Mir” station orbits. Space Res. 38(4), 355 (2000)Google Scholar
  46. 46.
    Bogomolov, A.V., Britvich, G.I., Myagkova, I.N., Ryumin, S.P.: Identification of neutrons from the background of gamma-quanta during registration by CsI(Tl) detectors. PTE (1), 13 (in Russian) (1996)Google Scholar
  47. 47.
    Butler, N.R., Kocevski, D., Bloom, J.S., et al.: A complete catalog of swift GRB spectra and durations: demise of a physical origin for pre-swift high-energy correlations. Appl. J. 671(1), 656 (2007)Google Scholar
  48. 48.
    Cane, H.V., Erickson, W.C., Kaiser, M.L., Raymond, J.C., et al.: Why did the January 20 2005 GLE Have Such a Rapid Onset? Fall 2005 AGU Abstract N SH21A-05Google Scholar
  49. 49.
    Charalambous, P.M., Dean, A.J., Lewis, R.A., Dipper, N.A.: The background noise in space born low-energy gamma-ray telescopes. Nucl. Instr. Meth A283, 533 (1985)ADSCrossRefGoogle Scholar
  50. 50.
    Cohen, M.B., Inan, U.S., Fishman, G.L.: Terrestrial gamma-ray flashes observed on BATSE/CGRO and ELF/VLF radio atmospherics. In: American Geophysical Union, Fall Meeting, abstract N AE33A-0944 (2005)Google Scholar
  51. 51.
    Crannell, C.J., Crannell, H., Ramaty, R.: Solar gamma Rays above 8 MeV. Astrophys. J. 229 762 (1979)ADSCrossRefGoogle Scholar
  52. 52.
    Crannell, C.J., Lang, F.L.: Nuclear gamma-ray ratios as spectral diagnostics for protons accelerated in solar flares. Proceedings of the Workshop on Nuclear Spectroscopy of Astrophysical Sourses, held in Washington, DC, December 14–16, p. 18 (1987)Google Scholar
  53. 53.
    Crownover, R.M.: Introduction to Fractals and Chaos. Jones and Bartlett Publ., London (1995)Google Scholar
  54. 54.
    Dean, A.J., Lei, F., Knight, P.J.: The space radiation environment and background noise in astronomical -ray telescopes. J. Br. Interplanetary Soc. 53(3–4), 91 (2000)ADSGoogle Scholar
  55. 55.
    Dean, A.J., Lei, F., Knight, P.J.: The space radiation environment and background noise in astronomical γ-ray telescopes. J. Br. Interplanetary Soc. 53(3–4), 91 (2000)ADSGoogle Scholar
  56. 56.
    Devicheva, E.A., Dobrovolsky, G.F., Kovalevskaya, M.A., et al.: Complex study of the Sun and solar-Earth physics. In: Proceedings of the III International Meeting CORONAS-I, Kaluga-88, L.: LPhTI, p. 99 (1989) (in Russian)Google Scholar
  57. 57.
    Dunphy, P.P., Chupp, E.L., Bertsch, D., Schneid, E., et al.: Neutrons and pion-decay gamma-rays from the solar flare of 1991 June 11. Bull. Am. Astron. Soc. 28, 857 (1996)ADSGoogle Scholar
  58. 58.
    Forrest, D.J., Chupp, E.L.: Simultaneous acceleration of electrons and ions in solar flares. Nature 305, 291 (1983)ADSCrossRefGoogle Scholar
  59. 59.
    Fractals in physics: In: Proceedings of the VI International Symposium on Fractals in Physics. M: Nauka (1988)Google Scholar
  60. 60.
    Gan, W.Q.: Spectral evolution of energetic protons in solar flares. Astrophys. J. 496, 992 (1998)ADSCrossRefGoogle Scholar
  61. 61.
    Gan, W.Q.: Solar gamma-ray spectroscopy and abundance of elements. Chin. J. Astron. Astrophys. 26, 255 (2002)ADSGoogle Scholar
  62. 62.
    Gehrels, P.M.: Instrumental background in gamma-ray spectrometers flown in low Earth orbit. Nucl. Instr. Meth. A313, 513 (1992)ADSCrossRefGoogle Scholar
  63. 63.
    Glyanenko, A.S., Arkhangelsky, A.I.: Analysis of the operation of the controller based on octagon systems-4020 plate in the AVS-F experiment onboard the CORONAS-F satellite during 3.5 years of operation. In: Abstracts of the “International Conference “CORONAS-F: Three Years of the Solar Activity Observations, 2001–2004” January 31–February 5, IZMIRAN, Troitks, p. 32 (2005) (in Russian)Google Scholar
  64. 64.
    Hartman, R.C., Bertsch, D.L., Bloom, S.D., Chen, A.W., et al.: The third EGRET catalog of high-energy gamma-ray sources. Astrophys. J. Suppl. 123, 79 (1999)ADSCrossRefGoogle Scholar
  65. 65.
    Horack, J.M., Fishman, G.J., Meegan, C.A., Wilson, R.B., et al.: BATSE observations of bremsstrahlung from electron precipitation events. In: Gamma-ray bursts, Proceedings of the Workshop, University of Alabama, Huntsville, 16–18 Oct 1991, p. 373 (1991)Google Scholar
  66. 66.
    Horack, J.M., Koshut, T.M., Mallozzi, R.S., Storey, S.D., et al.: Implications of the BATSE data for a helocentric origin of gamma-ray bursts. Astropys. J. 429, 319 (1994)ADSCrossRefGoogle Scholar
  67. 67.
    Imhof, W.L., Smith, R.V.: Observation of nearly monoenergetic high-energy electrons in the inner radiation belt. Phys. Rev. Lett. 14(22), 886 (1965)ADSCrossRefGoogle Scholar
  68. 68.
    Inan, U.S., Reising, S.C., Fishman, G.J., Horack, J.M.: Geophys. Res. Lett. 23(9), 1017 (1996)ADSCrossRefGoogle Scholar
  69. 69.
    Kalmykov, P.A., Arkhangelskaja, I.V., Arkhangelsky, A.I., Kotov, Yu.D., et al.: Modelling of the response of the detector of the AVS-F instrument of the CORONAS-F scientific equipment complex for the fluxes of space protons in the equatorial region of the Earth magnetosphere. Proceedings of the “Scientific Session of MEPhI-2007”, M.: MEPhI, vol. 7, p. 21 (in Russian) (2007)Google Scholar
  70. 70.
    Koshak, W.J., Krider, E.P.J.: Geophys. Res. 94, 1165 (1999)ADSCrossRefGoogle Scholar
  71. 71.
    Kotov, Yu.D., Belousova, I.V., Glyanenko, A.S., Bogovalov, S.V., et al.: Background Conditions aboard the KORONAS-I satellite as measured by the AVS instrument. Cosmic Res. 37(2), 42 (1999)Google Scholar
  72. 72.
    Kotov, Yu.D., Arkhangelskaja, I.V., Arkhangelsky, A.I., Glyanenko, A.S., et al.: Preliminary results of the processing of the data of the AVS-F instrument in the energy range of 0.1–11 MeV. Izvestiya RAN. Seriya phyzicheskaya, 66(11), 1666 (2002) (in Russian)Google Scholar
  73. 73.
    Kotov, Yu.D., Arkhangelskya, I.V., Arkhangelky, A.I., Glyanenko, A.S., et al.: Preliminary results of the processing of the AVS-F instrument data in the high-energy range. In: Proceedings “Scientific session MEPhI-2003”, M.: MEPhI, vol. 7, p. 20 (in Russian) (2003)Google Scholar
  74. 74.
    Kuznetsov, V.D.: The results of study of the sun and solar-terrestrial relations with the CORONAS-F satellite: a review. Solar Syst. Res. 39(6), 433–441 (2005)ADSCrossRefGoogle Scholar
  75. 75.
    Kuznetsov, V.D., Charikov, Yu.E., Kotov, Yu.D., Kuznetsov, S.N., et al.: A review of the solar results from CORONAS-F satellite. In: Multi-Wavelength Investigations of Solar Activity, IAU Symposium, vol. 223, p. 357. Cambridge University Press, Cambridge (2004)Google Scholar
  76. 76.
    Kuznetsov, V.D., Sobelman, I.I., Zitnik, I.A., Kotov, Yu.D., et al.: Results of solar observations on-board the “CORONAS-F” satellite. In: Proceedings of the 35th COSPAR Scientific Assembly, Paris, France, p. 812, 18–25 July 2004Google Scholar
  77. 77.
    Kotov, Yu.D. The features of the high energy emission generation during solar flares and possibilities of CORONAS-PHOTON satellite project of its investigation. In: 28 Russian Cosmic Ray Conference, Electronic Proceedings, 7–11 June 2004, M.: MEPhI, p. 2112 (2004)Google Scholar
  78. 78.
    Kotov, Yu.D., Arkhangelskaya, I.V., Arkhangelsky, A.I., Glyanenko, A.S., et al.: Study of gamma rays of solar flare of October 29, 2003 according to data of AVS-F and SONG instruments onboard CORONAS-F satellite. Bull Russian Acad Sci. Phys. 69(6), 859 (2005)Google Scholar
  79. 79.
    Kotov, Yu.D. and COR-PHOT TEAM.: Satellite project “CORONAS-PHOTON” for study of solar hard radiation. In: Proceedings of the 35th COSPAR Scientific Assembly, p. 1283, 18–25 July 2004, Paris, FranceGoogle Scholar
  80. 80.
    Kuzhevskij, B.M. Nuclear processes in the solar athmosphere and solar cosmic emission M. Energoatomizdat (1985) (in Russian)Google Scholar
  81. 81.
    Kuzhevskij, B.M., Gan, W.Q., Miroshnichenko, L.I.: The role of nuclei-nuclei interactions in the production of gamma-ray lines in solar flares. Chin. J. Astron. Astrophys. 5(3), 295 (2005)ADSCrossRefGoogle Scholar
  82. 82.
    Kuznetsov, S.N., Kudela, K., Myagkova, I.N., Yushkov, B.Yu.: X-ray and gamma-emission solar flare catalogue obtained by SONG onboard CORONAS-F satellite. In: Proceedings ISCS 2003 Symposium, “Solar Variability as an Input to the Earth’s Environment”, Tatranska Lomnica, Slovakia, 23–28 June 2003 (ESA SP-535, September 2003), p. 683Google Scholar
  83. 83.
    Kuznetsov, S.N., Bogomolov, A.V., Gordeev, Yu.P., Gotseluk, Yu.V., et al.: Preliminary results of SKL experiment onboard CORONAS-I satellite. Izvestiya RAS. Phys. 59(4), 2 (in Russian) (1995)Google Scholar
  84. 84.
    Kotov, Yu.D., Arkhangelskaja, I.V., Arkhangelsky, A.I., Glyanenko, A.S., et al.: Study of gamma rays of solar flare of October 29, 2003 according to data of AVS-F and SONG instruments onboard the CORONAS-F satellite. Bull. Ross. Akad. Nauk: Fiz. 69(6), 859–862 (2005)Google Scholar
  85. 85.
    Kostina, M.S., Arkhangelskaja, I.V., Arkhangelsky, A.I., Kotov, Yu.D., et al.: The investigation of the Neupert effect in faint solar flares on AVS-F data. In: Proceedings of the 31th International Cosmic Ray Conference. 7–15 July 2009, Lodz, Poland, pp.1551.1–1551.4. Published on CDROMGoogle Scholar
  86. 86.
    Lehtinen, N.G., Walt, M., Inan, U.S.: Geophys. Res. Lett. 23(19), 2645 (1996)ADSCrossRefGoogle Scholar
  87. 87.
    Mewaldt, R.A., Looper, M.D., Cohen, C.M., Mason, G.M., et al.: Space Weather Implications of the 20 January 2005 solar energetic particle event. American Geophysical Union, Spring Meeting 2005, N SH32A-05 (2005)Google Scholar
  88. 88.
    Murzin, V.S.: Introduction to the Cosmic Rays Physics. Atomizdat, Moscow (1979)Google Scholar
  89. 89.
    Nemets, O.F., Gofman, Yu.V.: Nuclear Physics Reference Book. “Naukova dumka”, Kiev (1975)Google Scholar
  90. 90.
    Pankov, V.M., Prokhin, V.L., Shkurkin, Yu.G., Glyanenko, A.S., et al.: X-ray semiconductor (CdTe) spectrometer for solar flare and preflare studies. Radiophys. Quant. Electron. 39(11–12), 1002–1005 (1996)ADSCrossRefGoogle Scholar
  91. 91.
    Pankov, V.M., Prokhin, V.L., Khavenson, N.G.: The XSS-1 X-ray CdTe spectrometer onboard the CORONAS-F satellite. Solar Syst. Res. 40(4), 314–318 (2006)ADSCrossRefGoogle Scholar
  92. 92.
    Porras, E., Sanchez, F., Reglero, V., Cordier, B., et al.: Production rate of proton-induced isotopes in different materials. Nucl. Instrum. Methods Phys. Res. B 160, 73 (2002)ADSCrossRefGoogle Scholar
  93. 93.
    Physics values reference book., // M.: Energoatomizdat (1991)Google Scholar
  94. 94.
    Ramaty, R., Murphy, R.J.: Nuclear processes and accelerated particles in solar flares. Space. Sci. Rev. 45, 213 (1987)ADSCrossRefGoogle Scholar
  95. 95.
    Ramaty, R., Mandzhavidze, N.: Gamma rays from solar flares. In: Proceedings of the IAU Symposium. Highly Energetics Physical Processes and Mechanisms for Emission from Astrophysical Plasmas, Montana State University, Bozeman, 6–10 July 1999, vol. 195, p. 12 (2000)Google Scholar
  96. 96.
    Ramaty, R., Mandzhavidze, N., Barat, C., Lockwood, J.A., et al.: The Giant 1991 June 1 flare: evidence for gamma-ray production in the corona and accelerated heavy ion abundance enhancements from gamma-ray spectroscopy. Astrophys. J. 479, 458 (1997)ADSCrossRefGoogle Scholar
  97. 97.
    Rubin, B.C., Lei, F., Fishman, G.J., Finger, M.H., et al.: A model of the gamma-ray background on the BATSE experiment. Astron. Astrophys. Suppl. 120, 687 (1996)ADSGoogle Scholar
  98. 98.
    Sanchez, F., Ballestros, F., Robert, A., Reglero, V., et al.: Background in low Earth orbits measured by LEGRI telescope—short and long term variability. Nucl. Instr. Meth. B155, 160 (1999)ADSCrossRefGoogle Scholar
  99. 99.
    Share, G.H., Murphy, R.J., Smith, D.M., Shih, A.Y., et al.: RHESSI Observations of the 2005 January 20 solar flare. In: Proceedings of the SHINE 2006 Workshop, p. 39. Zermatt Resort, Midway, Utah, DC. July 31–August 4 (2006)Google Scholar
  100. 100.
    Shih, A., Smith, D., Lin, R., Schwartz, R., et al.: Temporal variability of gamma-ray lines from the X-class solar flares of October–November 2003. 35th COSPAR Scientific Assembly, p. 3221. Held 18–25 July 2004, in Paris, France (2005)Google Scholar
  101. 101.
    Thompson, D.J., Bertch, D.L., Fichtel, C.E., Hartman, R.C., et al.: Calibration of the energetic gamma-ray experiment telescope (EGRET) for the Compton gamma-ray observatory. AJSS 86, 629 (1993)Google Scholar
  102. 102.
    Unan, U.S.: Lighting effects at high altitudes: sprites,elves, and terrestrial gamma ray flashes. C.R. Physique 2002 (3), 1411 (2002)Google Scholar
  103. 103.
    Vestrand, W.T., Forrest, D.J., Rieger, E., et al.: The solar maximum mission atlas of gamma-ray flares. Astrophys. J. Suppl. 120, 409 (1999)ADSCrossRefGoogle Scholar
  104. 104.
    Veselovsky, I.S., Panasyuk, M.I., Avdyushin, S.I., Bazilevskaya, G.A., et al.: Solar and heliospheric phenomena in October–November 2003: causes and effects. Cosmic Res. 42(5), 435–488 (2004)ADSCrossRefGoogle Scholar
  105. 105.
    Vishnevsky, O.V., Glyanenko, A.S., Pavlov, A.V., Pankov, V.M., et al.: Kalibration of the semiconductor detector XSS-1 of the CORONAS-F project. In: Proceedings of the “Sceintific session of MEPh-2001”, M.: MEPhI, vol. 7, p. 37 (2001) (in Russian)Google Scholar
  106. 106.
    Voronchev, V.T., Kukulin, V.I., Kuzhevskij, B.M.: Nucl. Instrum. Methods Phys. Res. A 525, 626 (2004)ADSCrossRefGoogle Scholar
  107. 107.
    Wescott, E.M., Sentman, D.D., Heavner, M.J., Hampton, D.L., et al.: Geophys. Res. Lett. 23(16), 2153 (1996)ADSCrossRefGoogle Scholar
  108. 108.
    Wigger, C., Hajdas, W., Zehnder, A., et al.: Proceedings of the Conference on Swift and GRBs: Unveiling the Relativistic Universe, San Servolo, Venice, 5–9 June 2006, Shpringer (2006)Google Scholar
  109. 109.
    Yermolaev, Yu.I., Zelenyi, L.M., Kuznetsov, V.D., Chertok, I.M., et al.: Magnetic storm of November, 2004: Solar, heliospheric, and magnetospheric disturbances. J. Atmos. Solar-Terrest. Phys. 70(2–4), 334–341 (2008)ADSCrossRefGoogle Scholar
  110. 110.
  111. 111.
    Arkhangelskaja, I.V., Amandzholova, D.B., Arkhangelsky, A.I., Kotov, Yu.D.: In: Procedings of the “Scientific session MEPhI-2005”, M.: MEPhI. vol. 7, p. 31 (2005) (in Russian)Google Scholar

Copyright information

© Springer-Verlag Berlin Heidelberg 2014

Authors and Affiliations

  • Yu. D. Kotov
    • 1
  • I. V. Arkhangelskaja
    • 1
  • A. I. Arkhangelsky
    • 1
  • S. N. Kuznetsov
    • 2
  • A. S. Glyanenko
    • 1
  • P. A. Kalmykov
    • 1
  • D. B. Amandzholova
    • 1
  • V. T. Samoylenko
    • 1
  • V. N. Yurov
    • 1
  • A. V. Pavlov
    • 1
  • O. I. Chervyakova
    • 1
  • I. V. Afonina
    • 1
  1. 1.National Research Nuclear University “MEPhI”MoscowRussia
  2. 2.D. V. Skobeltsyn Institute of Nuclear PhysicsM. V. Lomonosov Moscow State University (SINP MSU)MoscowRussia

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