THE MULTIELEMENT MERCURIC IODIDE DETECTOR ARRAY WITH COMPUTER-CONTROLLED MINIATURIZED ELECTRONICS FOR EXAFS

Construction of a 100-element HgI2 detector array, with miniaturized e lectronics, and software developed for synchrotron applications in the 5 keV to 35 keV region has been completed. Recently, extended x-ray a bsorption fine structure (EXAFS) data on dilute (similar to 1mM) metal lo-protein samples were obtained with up to seventy-five elements of t he system installed. The data quality obtained is excellent and shows that the detector is quite competitive as compared to commercially ava ilable systems. The system represents the largest detector array ever developed for high resolution, high count rate x-ray synchrotron appli cations. It also represents the first development and demonstration of high-density miniaturized spectroscopy electronics with this high lev el of performance. Lastly, the integration of the whole system into an automated Computer-controlled environment represents a major advancem ent in the user interface for XAS measurements. These experiments clea rly demonstrate that the HgI2 system, with the miniaturized electronic s and associated computer control functions well. In addition it shows that the new system provides superior ease of use and functionality, and that data quality is as good as or better than with state-of-the-a rt cryogenically cooled Ge systems.