Activation of the ASTRO-E hard X-ray detector in low Earth orbit

Author

Kokubun, M. ; Fukazawa, Y. ; Idesawa, E. ; Kataoka, J. ; Kamae, T. ; Matsuzaki, K. ; Mizuno, T. ; Saito, Y. ; Takahashi, T. ; Takizawa, K. ; Tashiro, M. ; Tamura, T. ; Yoshida, A.

Author_Institution

Dept. of Phys., Tokyo Univ., Japan

Volume

46

Issue

3

fYear

1999

fDate

6/1/1999 12:00:00 AM

Firstpage

371

Lastpage

376

Abstract

ASTRO-E hard X-ray detector (HXD) is characterized by well-type phoswich counters in a compound-eye configuration which reduce the detector background to lower level than any other past hard X-ray mission. When operating in low Earth orbit, the expected background of the HXD is an order of 10^-5 counts/s/keV/cm², mainly caused from the radioactivity induced within the detector materials by geomagnetically trapped protons. Results are presented from measurements of induced radioactivity in two phoswich scintillators, GSO (Gd₂SiO₅:Ce 0.5% mol) and BGO (Bi₄Ge ₃O₁₂), irradiated by mono-energetic protons at an accelerator facility. Radiation transport computer codes are used to build the detector response functions for emissions from decays of spallation products. Based on the comparison between experimental and simulation results, the activation background level of HXD in the orbit is estimated

Keywords

X-ray astronomy; X-ray detection; artificial satellites; astronomical telescopes; position sensitive particle detectors; proton effects; solid scintillation detectors; ASTRO-E hard X-ray detector activation; Bi₄Ge₃O₁₂; Gd₂SiO₅:Ce; activation background level; compound-eye configuration; detector response functions; geomagnetically trapped protons; induced radioactivity; low Earth orbit; monoenergetic protons; radiation transport computer codes; spallation products; well-type phoswich counters; Assembly; Collimators; Low earth orbit satellites; Plastics; Proton accelerators; Radiation detectors; Rubber; Satellite broadcasting; X-ray detection; X-ray detectors;

fLanguage

English

Journal_Title

Nuclear Science, IEEE Transactions on

Publisher

ieee

ISSN

0018-9499

Type

jour

DOI

10.1109/23.775546

Filename

775546