Sensitive X-Ray Fluorescence Detection for Higher Energies

X-ray fluorescence detection at intense synchrotron sources, used at DOE facilities for materials science research, is limited by the count rate of the solid state detectors. This project will develop a multilayer-analyzer array detector with high count rate, superb energy resolution, and fast time response. Utilizing diffraction from graded multilayers, the selection of energy photons will be achieved through an array of multilayer analyzers, and signals will be collected with high rate non-energy-resolving detectors, resulting in a detector with very high count rate. The multilayer-analyzer array detector will cover a large solid angle with superb energy resolution, and will be able to approach higher energies (>20KeV). Phase I will design the multilayers, with large acceptance angle and narrow bandwidth, which will be characterized using an x-ray beam. A prototype detector with three multilayers will be fabricated and evaluated at synchrotron beamlines against the performance of the solid-state detectors. In Phase II multilayer array detectors that cover a large solid angle will be developed. Commercial Applications and Other Benefits as described by the awardee: The multilayer detector should be 40 times more efficient, and have 2-3 times better energy resolution, than the state-of-the-art solid-state detectors used for fluorescence detection at intense beamlines. In addition to the synchrotron beamline application, the detector should enhance the detection of fluorescence in very dilute systems, say for the study of metal centers in biology under physiological conditions.