Microstructured Semiconductor Neutron Detector Arrays for Neutron Scattering Measurements

There is a need for high-resolution, high-efficiency, and high-rate neutron imaging detectors at neutron scattering facilities. The Oak Ridge National Laboratory Spallation Neutron Source neutron scattering instruments the VULCAN Engineering Diffractometer, the TOPAZ Crystal Diffractometer, and the Liquid and Magnetic Reflectometer; these instruments need thermal-neutron detecting arrays capable of 100-micron spatial resolutions that are not presently commercially available. Furthermore, the devices must be insensitive to gamma rays while retaining high thermal-neutron intrinsic detection efficiency, preferably above 30%. The objective of this project is to design and build for the first time a high- efficiency neutron detector array consisting of 2880-pixels, with each pixel being approximately 100- microns wide and 4-cm tall, all based on the microstructured semiconductor neutron detector technology. In addition, the detector array has the potential to be curved to the exact focal point of the work space to reduce parallax effects. The main objectives of the phase I work completed was to add new capabilities to, expand some existing capabilities on, and increase the technology readiness level of a prototype triple-stacked microstructured semiconductor neutron detector 1-dimensional array based on a proof-of-principle array previously developed by Kansas State University. For phase I, a 100-micron resolution prototype 64-pixel microstructured semiconductor neutron detector array was built and tested, which utilized stacked detectors and commercial charge-amplification ASICs. The main objectives for the phase II work will be to develop and fabricate a larger, high-efficiency 2880-pixel flexible array composed of twenty modular inter-linking 144-pixel stacked detector arrays. The full detector array has the potential to be curved to the exact focal point of the workspace to reduce parallax effects. Overall, the new detector array will have 2880-pixels that have 100-micron spatial resolution. The new technology will deliver compact, high spatial-resolution, high-efficiency, thermal- neutron detectors capable of real-time neutron measurements; such devices currently do not exist. Commercial Applications and OtherBenefits: Development of the novel solid-state neutron detector array design will benefit a wide spectrum of applications beyond those of neutron scattering instruments. The scientific and commercial impact from the proposed research is expected to be significant, where the technology can meet the imaging demands of new generations of neutron scattering instruments. The neutron-imaging device has direct applications in many other areas of science and engineering, such as in high-resolution neutron radiography/tomography, in neutron diffraction studies for stress/strain measurements in materials with internal defects, and for surface diffraction studies of coatings.