Speaker
Dr
Takeshi Nakamori
(Waseda University)
Description
It is important to obtain wide band X-ray/gamma-ray spectra at the same time in order to probe efficiently the emission processes or the structures of transient object such as gamma-ray bursts. We have developed, for future missions, an X-ray/gamma-ray detector utilizing reach-trough type avalanche photodiode (APD) array (8- and 16-segments) with the area of 1.6x1.8 cm^2. Excellent uniformity over the segments was achieved both in gain and energy resolution, where the deviations are less than 1.5 and 2%, respectively. We optically coupled the APD arrays with segmented CsI(Tl) scintillators fabricated to fit the APD pixel sizes. We irradiated gamma-ray source from the side of the APD. With this configuration X-rays are directly absorbed with the APD while gamma-rays are stopped by the CsI(Tl) where the APD works as a scintillation detector. These two events are discriminated by the differences in signal rise time using shaping amplifier with a time constant of 50 nano and 2 micro-seconds.We demonstrated that the two components were clearly separated and energy coverage was from about 1 keV to 1 MeV. Typical energy resolution for 662 keV and 32 keV was 8% and 9% (detected directly by the APD). These results shows that our detector can be used as a nice 1-dimentional imaging spectrometer. We propose to employ two sets of this detector for X- and Y- axis together with coded aperture masks for imaging the sky.
Preferred medium (Oral/poster)
poster
Author
Dr
Takeshi Nakamori
(Waseda University)
Co-authors
Dr
Jun Kataoka
(Waseda University)
Dr
Nobuyuki Kawai
(Tokyo Institute of Technology)
Dr
Takahiro Eonomoto
(Tokyo Institute of Technology)
Mr
Takahiro Toizumi
(Tokyo Institute of Technology)
Dr
Yoichi Yatsu
(Tokyo Institute of Technology)
Mr
Yoshitaka Ishikawa
(Hamamatsu Photonics, K. K.)
Mr
Yusuke Matsunaga
(Hamamatsu Photonics, K. K.)
