Speaker
Takuya Kato
(Waseda University)
Description
We have developed a large-area monolithic Multi-Pixel Photon Counter (MPPC) array consisting of 4×4 channels and flexible printed circuit (FPC) cables. Each channel has a photosensitive area of 3×3mm^2 and 3600 Geiger mode avalanche photodiodes (APDs). For a typical operational gain of 7.5×10^5 at +20 deg, gain fluctuation is only ±5.8% (RSD) over the MPPC device, and dark count rates (as measured at 1~p.e. level) amount to ~400kcps/channel, as averaged over the ten MPPC arrays developed in this paper. We first fabricated a gamma-ray camera consisting of the MPPC array with one to one coupling to a Ce-doped (Lu, Y)2(SiO4)O (Ce:LYSO) crystal array (4×4 array of 3×3×10mm^3 crystals). Energy and time resolutions of 11.5±0.5% (FWHM at 662keV) and 493±22ps were obtained, respectively. When using the charge division resistor network, which compiles signals into four position-encoded analog outputs, energy and time resolution of 10.2±0.4% (FWHM) and 837±94ps were obtained, respectively. Finally, we fabricated submillimeter Ce:LYSO scintillator matrices of 1.0 and 0.5mm^2 each, to further improve the spatial resolution. In both types of Ce:LYSO matrices, each of the crystals was clearly resolved in a position histogram, as an irradiated 137Cs source. The energy resolutions for the 662keV gamma-rays were 11.5±0.9 and 14.3±1.8% (FWHM), and the time resolutions were 872±84 and 996±149ps among all Ce:LYSO pixels for 1.0 and 0.5mm^2 Ce:LYSO matrices, respectively. These results suggest excellent potential for its use as a high spatial and time resolution medical imaging device, particularly in positron emission tomography (PET).
Author
Takuya Kato
(Waseda University)
Co-authors
Aya Kishimoto
(Waseda University)
Hidenori Matsuda
(Waseda University)
Hirokazu Ikeda
(ISAS/JAXA)
Jun Kataoka
(Waseda University)
Kazuhisa Yamamura
(Hamamatsu Photonics K.K.)
Kei Kamada
(Materials Research Laboratory, Furukawa Co., Ltd.)
Kenichi Sato
(Hamamatsu Photonics K.K.)
Nobuyuki Kawabata
(Hamamatsu Photonics K.K.)
Seiichi Yamamoto
(Kobe City College of Technology)
Shigeyuki Nakamura
(Hamamatsu Photonics K.K.)
Takamasa Miura
(Waseda University)
Takeshi Nakamori
(Waseda University)
Yoshitaka Ishikawa
(Hamamatsu Photonics K.K.)
