Geiger Photodiode Array Readouts for Scintillating Fiber Arrays

72725S03-I Scintillating and wavelength shifting fibers have increasingly demonstrated advantages over traditional radiation detection/tracking for high energy physics and nuclear physics experiments. As the number of channels increases, traditional instruments (photomultipliers, CCDs, and avalanche photodiode arrays) have been limited either by the size of the detector array or the performance. Geiger avalanche detection of optical signals is a candidate technology that would provide single photon sensitivity, high gain, and excellent gating capability. Although no commercial Geiger Photodiode (GPD) arrays are available on the market, it recently has been demonstrated that GPD arrays can be economically custom fabricated using high-volume-manufacturing Complementary Metal-Oxide Semiconductor (CMOS) technologies. This project will develop a rugged, compact, array of scintillating fiber readouts with superior photon counting performance, improved counting rate capability, and parallel readout, using innovative designs based on high-volume-manufacturing CMOS technologies. Phase I will design and fabricate GPD arrays and test their electro-optical performance and reliability. These arrays will be optically coupled to wavelength shifting fiber arrays, and their sensitivity and timing performance will be evaluated on a cosmic ray setup. Commercial Applications and Other Benefits as described by awardee: GPD arrays, coupled to large arrays of scintillating fibers, should have applications for high-energy physics and nuclear physics experiments. For example, they are currently under consideration for use at the next generation linear collider (NLC). The technology also should find use in large arrays of scintillating fibers in neutron tracking and imaging applications, and in field-deployable nuclear threat assessment units.