Ultrafast, Bright, and High-efficiency Scintillators for Dynamic Studies

Statement of the Problem Being Addressed: Hard X-ray high-speed imaging (HSI) technique is a unique research tool for studying transient phenomena in hard and soft condensed matter, in systems far from equilibrium, including materials under extreme conditions (stress, heat, etc.), failure of materials on impact, and the self-propagating exothermic reactions in metallic multilayers. The Advanced Photon Source (APS) at Argonne National Laboratory is currently being upgraded, with one emphasis being hard X-rays for real-time measurements of materials. While a variety of high-performance direct detectors are available in the 8 to 12 keV energy range, currently there are no suitable detectors that provide the high X-ray absorption, fast timing, and micrometer-scale resolution needed for hard X-ray HSI. This problem will be further exacerbated as more hard X-ray beamlines become operational. f) Statement of How this Problem is Being Addressed: Through the use of two technologies developed recently at RMD, we propose to demonstrate a novel hard X-ray HSI detector that simultaneously overcomes sensitivity, timing, and spatial resolution limitations of current detectors. g) What is to be done in Phase I: We propose to develop an ultrafast, bright, high-efficiency scintillation detector for time-resolved hard X-ray HSI applications. Specifically, we propose to develop novel transparent optical ceramic scintillators which are superior in all performance metrics (such as absorption efficiency, light output, decay time) compared with other scintillators currently being used in hard X-ray imaging. Furthermore, a novel laser pixelation technique developed recently at RMD will be adapted and improved to realize an unprecedented micrometer-scale resolution in the scintillator. Both the pixelation and scintillator fabrication technique proposed here have been proven to be robust, cost-effective and high-throughput methods that could easily be scaled up. The proposed project will concentrate on larger-area detectors for imaging and radiography applications on nanosecond time scales, and will allow a push toward higher detective quantum efficiencies (DQEs) over a wider band of X-ray energies than can presently be obtained with available phosphors. h) Commercial Applications and Other Benefits: Example research areas that stand to benefit from the proposed development include measurements of strain and texture during thermo-mechanical deformation, studies of composite materials, studies of layered systems, such as those with applied protective coatings, and dynamic studies of materials under extreme stress. Due to its extraordinary properties, we expect the proposed scintillator array technology to see widespread use in important synchrotron applications and have high commercial appeal. i) Keywords: Ultrafast scintillator, bright scintillator, high-speed imaging, synchrotron detector, hard X-ray imaging, transparent optical ceramic, laser pixelation. j) Summary for Members of Congress: The development of the proposed structured scintillator array will allow utilization of the full potential of current state-of-the-art synchrotron sources with applications in medical imaging, scanning equipment for border patrol and homeland security, and small animal research (essential to the rapid and cost-effective development of new drugs).