Abstract
In the present study, the Monte Carlo calculations were carried out to evaluate the effect of beam divergence on the response of a spherical thermal-neutron counter at the center of a spherical moderating assembly. A model of 3He detector surrounded with 10 in. diameter polyethylene sphere was utilized to calculate the point isotropic and plane-parallel beams responses of twelve different energies, and obtain the geometry factor and its parameters (a 4 and a 5) based on general formulations. Furthermore, for 2, 3, 5, 8, 10 and 15 in. spheres exposed to three different radionuclide neutron sources with various energy spectra, the parameters of geometry factor were quantified, as a function of moderator radius and neutron energy. Obtained results based on this method were compared with the experimental data for one specific source. Finally, by these parameters the obtained values of the geometry factor based on two formulations were compared to each other.
Similar content being viewed by others
References
Griffith RV, Hankins DE, Gammage RB, Tommasino L, Wheeler RV (1979) Recent developments in personnel neutron dosimeters. Health Phys 36:235–260
Eisenhauer CM, Hunt JB, Schwartz RB (1985) Calibration techniques for neutron personal dosimetry. Radiat Prot Dosim 10:43–57
Knoll GF (1989) Radiation detection measurement, 2nd edn. Wiley, New York
Vega-Carrillo HR, Hernandez-Almaraz B, Hernandez-Davila VM, Montalvo TR, Ortiz-Hernandez A (2010) Neutron spectrum and doses in a 18 MV LINAC. J Radioanal Nucl Chem 283:261–265
Bramblett RL, Ewing RI, Bonner TW (1960) A new type of neutron spectrometer. Nucl Instrum Methods 9:1–12
ISO 8529–2 (2000) Reference neutron radiations-part 2: calibration fundamentals of radiation protection devices related to the basic quantities characterizing the radiation field. International Organization for Standardization, Geneva
Axton EJ (1972) The effective centre of a moderating sphere when used as an instrument for fast neutron flux measurement. J Nucl Energy 26:581–583
Hunt JB (1984) The calibration of neutron sensitive spherical devices. Radiat Prot Dosim 8:239–251
Harrison KG (1981) The calibration of neutron detectors with spherical moderators. Nucl Instrum Methods 184:595–597
Khabaz R, Izadi R (2012) Quantifying the geometry correction factor and effectiveness parameter for Bonner sphere spectrometer with 3He counter. J Radioanal Nucl Chem 295:1487–1493
Khabaz R (2013) Examining the departure in response of non-point detectors due to non uniform illumination and displacement of effective center. Nucl Instrum Methods A 728:145–149
Kluge H, Weise K, Hunt JB (1990) Calibration of neutron sensitive spherical devices with bare and D2O-moderated 252Cf sources in rooms of different sizes. Radiat Prot Dosim 32:233–244
Khabaz R, Miri H (2011) Development of a Bonner sphere spectrometer with emphasis on decreasing the contribution of scattering by using a new designed shadow cone. J Radioanal Nucl Chem 289:789–794
ICRP (1973) Data for protection against ionizing radiation from external sources. Pergamon Press, Oxford
Briesmeister JF (2000) MCNP-a general Monte Carlo N-particle transport code, Version 4C. Los Alamos National Laboratory Report LA-13709-M, Los Alamos
Taylor GC (2010) Geometry corrections for cylindrical neutron area survey meters. Appl Radiat Isotop 68:546–549
Griffith RV, Palfalvi J, Madhvanath U (1990) Compendium of neutron spectra and detector responses for radiation protection purposes. International Atomic Energy Agency, Technical Report Series No. 318
ISO 8529–1 (2001) Reference neutron radiations—part 1: characteristic and methods of productions. International Organization for Standardization, Geneva
Author information
Authors and Affiliations
Corresponding author
Rights and permissions
About this article
Cite this article
Khabaz, R. Investigation of the effects of beam divergence on the response of neutron voluminous detectors. J Radioanal Nucl Chem 300, 911–917 (2014). https://doi.org/10.1007/s10967-014-3084-3
Received:
Published:
Issue Date:
DOI: https://doi.org/10.1007/s10967-014-3084-3