AN ISPA-CAMERA FOR GAMMA-RAYS IN NUCLEAR-MEDICINE

With the recently developed ISPA (Imaging Silicon Pixel Array)-tube we achieved high position-sensitive detection efficiency of Co-57-122 ke V photons, via a matrix of YAlO3-crystals (YAP), 5 mm long, 0.6 x 0.6 mm(2) cross-section. The ISPA-tube is only 4 cm long with 3.5 cm diame ter and consists of a photocathode viewed at 3 cm distance by a silico n pixel chip, directly detecting the photoelectrons. The chip-anode co nsists of 1024 rectangular pixels with 75 mu m x 500 mu m edges. Each pixel is bump-bonded to its individual front-end electronics which pro vides read-out times between 6 and 12 mu s. Apart from its already dem onstrated application in HEP for particle tracking with scintillating fibres, the ISPA-tube provides also an excellent tool in medicine, bio logy and chemistry.