Speaker
Mr
Katsuhiro Hayashi
(Hiroshima University)
Description
Hard X-ray Imager (HXI) and Soft Gamma-ray Detector (SGD) onboard the 6th Japanese X-ray satellite, ASTRO-H, which is scheduled to be launched in 2014, utilize the double-sided silicon strip detector (DSSD) and the pixel array type silicon sensor (Si-pad), respectively. DSSD with a strip pitch of 250 um in a 3.4 cm x 3.4 cm area has imaging capability in 5-30 keV with an energy resolution of 1–2 keV (FWHM) in both the P and N sides. Si-pad consists of 16 x 16 pixels with the pixel size of 3.2 mm x 3.2 mm is utilized to determine the photon direction by the Compton kinematics in 10-600 keV. Since the ASTRO-H will be operated in the low earth orbit, these detectors are damaged by the irradiation of cosmic-ray protons mainly in the South Atlantic Anomaly. The total radiation level in the orbit is about 1 krad per one year, and the leakage current increases gradually by the produced damage in the sensor. In order to evaluate the damage of the sensor by the irradiation, we have carried out 60Co gamma-ray radiation tests with a total dose of 1, 3, 5 and 10 krad, and a 150 MeV proton beam bombardment with the total dose of 10 years irradiation level. In the both experiments, the leakage current level became larger by a factor of 2-3, resulted in the effect on the noise level is small if we continue the mission for 10 years, and it is found that the radiation effects are not significant under the operation temperature of -15C for the ASTRO-H. In this presentation, we report the summary of the basic performance of the detectors, and the radiation effects on the sensors by the irradiation tests.
Author
Mr
Katsuhiro Hayashi
(Hiroshima University)
Co-authors
Mr
Hajimu Yasuda
(Hiroshima University)
Prof.
Hiromitsu Takahashi
(Hiroshima University)
Prof.
Hiroyasu Tajima
(Nagoya University)
Prof.
Hisashi Kitamura
(NIRS)
Mr
InChun Park
(Hiroshima University)
Prof.
Kazuhiro Nakazawa
(The Universitiy of Tokyo)
Mr
Kyohei Dotsu
(Hiroshima University)
Prof.
Masanori Ohno
(Hiroshima University)
Mr
Masayuki Matsuoka
(Hiroshima University)
Prof.
Motohide Kokubun
(ISAS/JAXA)
Prof.
Shin Watanabe
(ISAS/JAXA)
Mr
Sho Nishino
(Hiroshima University)
Prof.
Tadayuki Takahashi
(ISAS/JAXA)
Prof.
Takaaki Tanaka
(KIPAC/Stanford University)
Prof.
Takashi Ohsugi
(Hiroshima University)
Prof.
Tsunefumi Mizuno
(Hiroshima University)
Prof.
Yasushi Fukazawa
(Hiroshima University)
Prof.
Yukio Uchihori
(NIRS)
