1989 Volume 38 Issue 3 Pages 117-122
A low noise charge-sensitive preamplifier for scintillation detector system using the photodiode read-out of scintillation light has been developed. The input stage of the preamplifier consists of four selected FFTs (2 sk 505, gm=26 mS) . The characteristics of the preamplifier are obtained as: (1) rise time is less than 10 ns, (2) ENC (equivalent noise charge, FWHM) =1.1×10-16C with connected to the S 1723-06 photodiode (Hamamatu photonics, sensitive area 10 mm×10 mm), (3) open loop gain =2.4×104.
Using this low noise preamplifier, the scintillation spectrometer system has been constructed with a 10×10×10 mm3 CsI (Tl) scintillator and S 1723-06 photodiode, the energy resolutions of which have been 6.1% and 42% (FWHM) for 662 keV and 60 keV gamma-rays respectively. As another application, the α-ray detector has been successfully constructed using the present low noise preamplifier attached to the S3204 photodiode with ZnS (Ag) scintillator, where the equivalent noise charge of the system was as low as 3×10-16C.
