Low-cost Individual Digital Dosimeters using Solid State Photomultipliers

U.S. forces working in low-level radiation environments have unsatisfactory choices for monitoring radiation exposure. The currently available A/UDR-13 pocket dosimeter is able to meet sensitivity requirements, but is cost prohibitive at ~$400 per unit, and it fails in the high temperature environments faced our military. Careful monitoring and accurate reporting of the exposed dose will reduce threats to the defense of our soldiers and our nation. The solution to these problems is an integrated detector-on-a-chip using a solid-state photomultiplier (SSPM) fabricated with CMOS (complementary metal-oxide-semiconductor) technology. An array of CMOS avalanche photodiode (APD) pixels comprises the SSPM, which is monolithically integrated to the readout and USB data transfer electronics. Coupling this detector-on-a-chip to a scintillation crystal provides an integrated platform for a low-cost, rugged, digital dosimeter. The Phase I work will demonstrate the feasibility of utilizing a SSPM, coupled to a scintillation crystal, to provide a low-cost, rugged, temperature tolerant individual digital dosimeter by measuring the sensitivity and energy resolution of a prototype, at two temperature extremes, and performing an analysis of the production costs.