Electronics for Large Superconducting Tunnel Junction Detector Arrays for Synchrotron Soft X-ray Research

The Department of Energy provides four national synchrotron radiation facilities to support advanced research in all fields by supplying intense brilliant x-ray beams covering a wide range of energies. However, x-ray detector development has not kept pace with developments in x-ray sources and beam line facilities. For example, current detectors do not have adequate energy resolution for use in the soft x-ray regime (0.2 ¿ 2.0 KeV). This is an issue because much important science could be done if adequate detectors were available. In the past 5-10 years, superconducting tunnel junction (STJ) detectors have been developed that are capable of delivering 10-20 eV energy resolution at high count rates in this soft x-ray regime. However, because these detectors are tiny (200 µm x 200 µm), they need to be used in arrays of 100s or 1,000s to be effective. This project will develop low cost, easy to use electronics to support such large arrays cost effectively, so that a 1,000-element STJ detector array could be purchased for the same price as the large HPGe now being used in the hard x-ray regime, while delivering 100s of times more counts with at least 5-times-better energy resolution. In Phase I, the concept will be tested with an ultra-compact, low noise preamplifier and coupled to an existing digital processor. Commercial Applications and other Benefits as described by the awardee If successful, these detectors would allow the nation's synchrotron facilities to significantly enhance the scientific return on investment in x-ray sources by opening up the soft x-ray regime to highly productive fluorescence analysis techniques. In addition, by providing detectors optimized for very-low-voltage scanning electron microscopy, these detectors would benefit the semiconductor industry by providing a superior way to study manufacturing defects.