Low Cost Digital Electronics for Isotope Analysis with Microcalorimeters

78226S For its nuclear non-proliferation and nuclear attribution efforts, the DOE requires highly sensitive instruments to accurately analyze the isotope ratios of uranium, plutonium and other radioactive elements in collected samples. Because existing gamma ray spectrometers do not have adequate energy resolution to resolve the emission lines central to these analyses, superconducting transition edge microcalorimeters are being developed to achieve the required energy resolution. Further, because the mass of each microcalorimeter is small, they must be fabricated in large arrays. In turn, this will require compact, low cost readout electronics with good energy resolution and higher count rate capability; otherwise, the overall instrument would not be practical. In this project, the high precision digital readout electronics and digital filter algorithms, which had previously been developed for germanium detectors, will be adapted to microcalorimeters. Energy resolutions comparable to the existing electronics should be achievable, but with much higher throughput. The goal will be the development of compact electronics that can be built at a price of $100 per channel with automated software for setup, calibration, and monitoring for 100-1000 channels. In Phase I, the hardware and processing algorithms of exisiting digital electronics for germanium detectors will be modified for microcalorimeter detectors, based on results from initial off-line analysis of captured signal pulses. The performance of the modified system will be tested on a microcalorimeter at Lawrence Livermore National Laboratory. A preliminary design and cost estimate of a multi-channel prototype board will be created for construction in Phase II. Commercial Applications and Other Benefits as described by the awardee: The proposed approach to enhancing the detection and deterence of nuclear proliferation and resultant increases in national security carries a high public benefit, in and of itself. Providing electronics for the required verification instruments should also carry some modest commercial success, with projected sales of a few million dollars. These instruments, however, have much wider areas of application in various scientific experiments employing arrays of microcalorimeters for X-ray or gamma-ray spectroscopy. In particular, there is a significant effort at NIST and elsewhere to develop similar instruments for quality control in semiconductor processing.