Title :
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
fDate :
6/1/1999 12:00:00 AM
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;
Journal_Title :
Nuclear Science, IEEE Transactions on
