R&D of a new 1-dimensional /spl gamma/-ray position sensor using scintillators coupled to a Si strip detector

As the detection part of an improved Fourier synthesis imager, we developed a new one-dimensional gamma-ray position sensor consisting of inorganic scintillators whose lights are read out by a silicon strip detector (SSD). The employed SSD has no metal anode, with its Al-cathode divided into 32 channels of 400 mum pitch. Electrodes of all channels are Al-bonded to a low noise analog ASIC, so that signals can be read out from all channels simultaneously. We fabricated a "stacked CsI scintillator", consisting of 20 CsI(Tl) scintillator plates each having a dimension of 10 mm times 10 mm times 0.3 mm, and 0.07 mm-thick light reflective sheets inserted between adjacent CsI plates. Coupling the scintillator and the SSD, gamma-ray with energies gsim 500 keV were successfully detected, with a position resolution of ~0.37 mm