Solar Physics

, Volume 65, Issue 1, pp 25–37 | Cite as

The Hard X-Ray Burst Spectrometer on the Solar Maximum Mission

  • L. E. Orwig
  • K. J. Frost
  • B. R. Dennis


The primary scientific objectives of the Hard X-Ray Burst Spectrometer (HXRBS) to be flown on the Solar Maximum Mission are as follows: (1) To determine the nature of the mechanisms which accelerate electrons to 20–100 keV in the first stage of a solar flare and to > 1 MeV in the second stage of many flares; and (2) to characterize the spatial and temporal relation between electron acceleration, storage and energy loss throughout a solar flare.

Measurements of the spectrum of solar X-rays will be made in the energy range from 20 to 260 keV using an actively-shielded CsI(Na) scintillator with a thickness of 0.635 cm and a sensitive area of 71 cm2. Continuous measurements with a time resolution of 0.128 s will be made of the 15-channel energy-loss spectrum of events in this scintillator in anticoincidence with events in the CsI(Na) shield. Counting-rate data with a time resolution as short as 1 ms will also be available from a limited period each orbit using a 32K-word circulating memory triggered by a high event rate.

In the first year after launch, it is expected that approximately 1000 flares will be observed above the instrument sensitivity threshold, which corresponds to a 20–200 keV X-ray flux of 2 × 10−1 photons (cm2 s)−1 lasting for at least one second.


Flare Event Rate Time Resolution Solar Flare Temporal Relation 
These keywords were added by machine and not by the authors. This process is experimental and the keywords may be updated as the learning algorithm improves.


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  1. Bai, T.: 1978, Solar Phys. 59, 141.Google Scholar
  2. Datlowe, D. W., Elcan, M. J., and Hudson, H. S.: 1974, Solar Phys. 39, 155.Google Scholar
  3. Dennis, B. R., Suri, A. N., and Frost, K. J.: 1973, Astrophys. J. 186, 97.Google Scholar
  4. Dennis, B. R., Frost, K. J., Lencho, R. J., and Orwing, L. E.: 1977, Space Sci. Instr. 3, 325.Google Scholar
  5. Dröge, F.: 1977, Astron. Astrophys. 57, 285.Google Scholar
  6. Frost, K. J. and Dennis, B. R.: 1971, Astrophys. J. 165, 655.Google Scholar
  7. Frost, K. J., Dennis, B. R., and Lencho, R. J.: 1971, in F. Labuhn and R. Lüst (eds.), ‘New Techniques in Astronomy’, IAU Symp. 41, 185.Google Scholar
  8. Goodman, N. B.: 1976, Space Sci. Instr. 2, 425.Google Scholar
  9. Hudson, H. S.: 1978, Astrophys. J. 224, 235.Google Scholar
  10. Hurley, K. and Duprat, G.: 1977, Solar Phys. 52, 107.Google Scholar
  11. Kaufman, P., Strauss, F. M., Opher, R., and Laporte, C.: 1979, Astron. Astrophys., in press.Google Scholar
  12. Slottje, C.: 1978, Nature 275, 520.Google Scholar
  13. van Beek, H. F.: 1973, ‘Development and Performance of a Solar Hard X-Ray Spectrometer’, Utrecht University (Ph.D. Thesis).Google Scholar

Copyright information

© D. Reidel Publishing Co. 1980

Authors and Affiliations

  • L. E. Orwig
    • 1
  • K. J. Frost
    • 1
  • B. R. Dennis
    • 1
  1. 1.Laboratory for Astronomy and Solar Physics, NASA-Goddard Space Flight CenterGreenbeltU.S.A.

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