Sensitive X-Ray Fluorescence Detection for Higher Energies

X-ray spectroscopy and micro-spectroscopy experiments at synchrotron sources (such as the Advanced Photon Source at Argonne National Laboratory and the Advanced Light Source at Lawrence Berkeley Laboratory) are limited by the count rate and energy resolution limitations of solid state x-ray fluorescence detectors. This project will further develop highly sensitive and efficient multilayer array analyzer detectors, which will improve upon a previous design. Utilizing diffraction from graded multilayers, the selection of energy photons will be achieved through an array of multilayer analyzers, and the signal will be collected with high-rate non-energy-resolving detectors, resulting in a detector with very high count rate. The multilayer array analyzer detector will cover a large solid angle with superb energy resolution, and will be able to approach higher energies. Phase I demonstrated that multilayers with high efficiency and narrow reflectance can be fabricated. In addition, it was shown that superb background rejection can be achieved with a double multilayer configuration. In Phase II, a full-scale array detector and two modular detector units will be fabricated to cover an energy regime from 3 KeV to 20 KeV. The detectors will be characterized and compared with currently available detector systems. Commercial Application and Other Benefits as described by the awardee: The multilayer detector should provide 50 times more efficiency in fluorescence detection than state-of-the-art solid-state detectors at intense beamlines, with 2-to-3 times better energy resolution. The detectors will be commercialized for use at synchrotron sources around the world. In addition to the synchrotron application, the technology should have application to microanalysis studies that use other types of radiation.