Superconducting Tunnel Junction Detectors for High-Resolution X-Ray Spectroscopy

X-ray absorption spectroscopy is a widely used experimental technique for studying the composition and chemistry of materials and is one of the driving forces behind the explosive growth of synchrotron light sources and their increase in brightness by many orders of magnitude. However, advances in detector technology have not kept pace with advances in synchrotron brightness, leading to limitations on scientific output and research capabilities. General statement of how this problem is being addressed Superconducting tunnel junction (STJ) X-ray detectors based on Ta thin films offer both high energy resolution and high count rate capability, two key features needed to meet growing demands for advanced detectors for synchrotron science applications. Work completed during Phase I and II We successfully fabricated several prototype STJ detectors and detector arrays during Phase I and Phase II. These prototypes have been characterized at the synchrotron, where we demonstrated world record energy resolution using a prototype multi-pixel STJ detector array. Plans for the Phase IIB project For Phase IIB, STAR Cryoelectronics proposes to extend the scope of the Phase II project to develop next-generation STJ detectors with significantly improved energy resolution and speed, both of which will enhance the competitive advantage of this detector technology and accelerate successful commercialization. Commercial applications and other benefits The new X-ray spectrometer based on STJ detector arrays will meet compelling needs for improved detector instrumentation for X-ray absorption spectroscopy (XAS) at the synchrotron. This powerful spectroscopy technique is used to study the local molecular and electronic structure of specific elements. XAS samples can be highly diluted and generally do not require substantial pre-treatment, and they can range from chemicals and biological samples or tissues to soils and rocks. The significant performance enhancements that will be realized with the STJ Xray spectrometer will lead to greater scientific productivity and return on the Nations substantial capital investment in synchrotron facilities.K86