High gain avalanche photodiode arrays for DIRC applications

The detection of light emitted in Cherenkov radiators requires fast detecto r arrays with high sensitivity to short wavelength photons. Photomultiplier tubes, the traditional imaging detectors for short wavelength optical radi ation, have limited spatial resolution and require expensive anti-magnetic shielding. We report on the performance of a new, Geiger mode operated, silicon micro- avalanche photodiode (mu APD) array, designed for Cherenkov light imaging a pplications. We address issues of optical interfacing, speed, and pulse spe ctra achievable with these mu APDs. The new mu APD array provides a high sensitivity detector for applications requiring two dimensional light mapping with single photon sensitivity. The se features make it a promising candidate for the detection of Cherenkov li ght in modern high energy physics experiments.