X-RAY ASORPTION SPECTROSCOPY FOR TRACE ANALYSIS OF CHEMICAL PHASE AND COMPOSITION

X-RAY ABSORPTION SPECTROSCOPY (XAS) BASED AT SYNCHROTRON FACILITIES IS AN ESTABLISHED RESEARCH TOOL IN A VARIETY OF FIELDS INCLUDING BIOCHEMISTRY, CATALYSIS, AND MATERIALS SCIENCE. FOR TRACE ANALYSIS, XAS OFFERS IMPORTANT PHASE INFORMATION AS WELL AS ELEMENTAL COMPOSITION. COMMERCIALIZATION WILL DEPEND ON INCREASED PERFORMANCE OF THE X-RAY DETECTION SYSTEM. THIS PHASE I PROJECT WILL LEVERAGE UNIVERSITY EXPERTISE AND DOE LABORATORY FACILITIES BY TRANSFERRING IMPROVED TECHNIQUES TO THE PRIVATE SECTOR SMALL BUSINESS. AN IMPROVED DETECTOR SYSTEM IS PLANNED, BASED ON AN ARRAY OF SILICON AVALANCHE PHOTODIODES HAVING THE FOLLOWING ADVANTAGES: (1) OPERATION AT OR NEAR ROOM TEMPERATURE, (2) INTERNAL SIGNAL GAIN AND LOWER NOISE, (3) GOOD EFFICIENCY UP TO 15 KEV, AND (4) GOOD ENERGY DISCRIMINATION. THIS DETECTOR WILL IMPROVE ON CONVENTIONAL GERMANIUM (GE) AND SILICON (LITHIUM) SI(LI) DETECTORS PRIMARILY BY ELIMINATION OF THE BULKY COOLING APPARATUS, THEREBY REDUCING THE COST AND INCREASING THE OVERALL FLEXIBILITY. APPLICATION TO ANALYSIS OF THE CHEMICAL PHASE OF TRACE METAL COMPOUNDS IN SOILS WILL FORM AN EARLY DEMONSTRATION OF THE POWER OF THIS TECHNIQUE. THE INFORMATION GAINED FROM THIS PROJECT WILL ALSO CONTRIBUTE TO EVALUATION OF THE POTENTIAL FOR APPLICATION OF THE TECHNOLOGY TO RELATED AREAS OF X-RAY RESEARCH.