This Small Business Innovation Research (SBIR) Phase II project aims to produce a new, high-resolution x-ray detector for fluorescence measurements of lighter elements. For x-rays generally near 30 keV and below, there exist several tradeoffs between today's choices of lithium drifted silicon (Si/Li)) detectors and high purity germanium (HPGe) detectors. Si/Li) detectors offer simple spectral decomposition but have limited active volumes. Conversely, HPGe detectors can offer larger sizes, but pulse height analysis is complicated by short x-ray penetration and overlapping escape peaks. The technical goal is to develop a detector from high purity silicon, with a contact structure that allows for increasing detection volumes without high capacitance -antithetical to high-count rates. The work will entail device design and computational modeling, developing new electrical contact fabrications on high purity silicon, manufacturing numerous test detectors and evaluation under various conditions, including temperature.
The impact of this technology could be how the detectors will be utilized and the basic science learned through the fabrication process. These detectors are used in many applications for the identification of completely diverse samples. Just a few examples include materials science, surface science, environmental analysis, industrial process and quality control, forensic sciences and archaeology, and geological and extraterrestrial exploration. In virtually any of these applications, a new detector providing greater counting efficiency yields more productive and definitive results.
