Temperature Dependence of A valanche Photodiodes for Scintillating Fiber Readout

摘要

We have evaluated the performance of avalanche photodiodes (APDs) as photosensors for scintillating-fiber charged particle tracking detectors, putting special emphasis on their temperature dependence. For this purpose, we built a prototype of a scintillating fiber hodoscope with 3HF scintillating fibers 0.5 mm in diameter. The fiber array structure was so designed that each APD could receive photons from two fibers along a particle trajectory penetrating the array. By cooling the APDs to -40 deg C, we could achieve the signal-to-noise ratio larger than 25. The detection efficiency reached more than 98 percent with reducing the noise count rate to 0.5 percent.