High gain avalanche photodiode arrays for DIRC applications

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