In response to the need for compact, rugged gammaray sensors with high counting efficiency and good photopeak resolution, this project will develop sensor technology for both aboveground surface contamination mapping as well as for underground (well logging) applications. This work derives from the recent development of high resolution gamma detectors in the Yale University physics department based on xenon near its thermodynamical critical point. The Phase I objective is to design, construct, test and evaluate for gamma ray performance (photopeak resolution, absolute efficiency, count rate) a detector operating at room temperature at xenon densities from 0.t to 1.4 grams/ml. In addition, the potential improvements in performance, particularly dead-time (count rate), with the addition of 1 to 5g: helium will be measured.Anticipated Results /Potential Commercial Applications as described by the awardee:The sensor technology of a compact, high resolution, room temperature, portable gamma-ray detector will find application in environmental measurements, industrial process monitoring, and nuclear medicine.
