Speaker
Description
LaBr3:Ce crystals are used for radiation imaging in medical physics, with PMT or SIPM readout. An R&D was pursued with 1/2 and 1" crystals to realize compact large area detectors (up some cm$^2$ area) with SIPM array readout, aiming at high light yields, good energy resolution/linearity and fast time response for low-energy X-raysdetection. This study was triggered by the FAMU experiment at RIKEN-RAL muon facility, that aims at the precise measure of the proton Zemach radius to solve the so-called ``proton radius puzzle'', triggered by the recent measurements of the proton charge radius at PSI. The goal is the detection of characteristic X-rays around 130 keV. Other applications may be foreseen in medical physics, such as PET and gamma-ray astronomy. A direct and simple readout scheme employing CAEN V1730 fast digitizers was used. Different experimental key factors were studied such as the use of different SIPM arrays for readout from Hamamatsu, Advansid and SENSL, the drift of SIPM gain with temperature, the comparison of performances and intrinsic activity with other available crystals. The temperature gain drift of SIPM was corrected online by the use of custom NIM modules, based on CAEN A7585D power supply chips with temperature feedback. Laboratory tests and beam results will be reported. In laboratory, an energy resolution @ Cs$^{137}$ peak around 3% was obtained. This compares well with the best results obtained with the standard PMT readout.
First author | Bonesini Maurizio |
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maurizio.bonesini@mib.infn.it | |
Collaboration / Activity | FAMU / detector R&D |