Xenon 3D Detector for Gamma Ray Astronomy

This Small Business Innovation Research (SBIR) project will seek to achieve a quantum leap in sensitivity of gamma ray astronomy in the 100 keV to 10 MeV region through development of a novel high pressure xenon (HPXe) detector element for imaging the region of interest. This development will incorporate (1) a cost-effective means of containing HPXe safely up to pressures of 3240 psig, (2) innovative means of measuring the spatial coordinates of gamma ray interactions within the HPXe detecting element for high quality spatial and angular measurements, and (3) novel methods of realizing the optimal spectroscopic properties of HPXe at a density of 0.55 g/cm3 to achieve an energy resolution approaching 0.45% at 1 MeV. A large array of such detecting elements could provide the ideal detector for a next generation HPXe Compton gamma ray telescope, having an angular resolution of a few tenths of a degree and providing a hundred-fold increase in sensitivity over that predicted for the upcoming Integral (SPI) satellite gamma observatory. A scaled down version of such a telescope could also be used for regional neutron activation analysis of the Martian surface, remote detection applications, or an excellent alternative to HPGe detectors currently used in laboratory settings. The anticipated outcome of this project is a new basic detector element, which can be used for a variety of space physics, field detection, and laboratory applications. The physical characteristics of such a detector combined with an order of magnitude improvement in energy resolution make it well suited for gamma detection in the 100 keV to 5 MeV band aboard satellite or balloon-borne instruments. Another very exciting application of this technology is a spectrometer for detection of radiation emitted as a result of neutron activation of the Martian surface. Such research could provide important data regarding planetary soil composition. In addition to astrophysics applications, a high energy resolution detector element based on high pressure xenon cylindrical detectors has significant commercial potential as a replacement for HPGe because the requirement of cryogenic cooling is eliminated, resulting in greater convenience and broader applicability. HPGe is currently employed in many laboratory settings, and the proposed technology could offer a cheaper and much more convenient alternative.