A Compact Crystal Positioning System for Neutron Diffraction

79518S When completed, the Spallation Neutron Source¿s (SNS) multiple beamlines will provide unprecedented opportunities to conduct studies in materials characterization, medical isotope production, and the transmutation of nuclear waste. However, the large goniometers traditionally used to position samples relative to particle beams will be incompatible with many of the new SNS instruments. Therefore, to take full advantage of the greatly reduced data collection times made possible by the SNS¿s high neutron flux, new automated sample changers must be developed and deployed. This project will develop a radically new approach to sample loading and orientation. A compact, high-precision manipulator, adjustable in six degrees-of-freedom, will be mounted within the bore of a temperature control cryostat. A kinematic ¿socket¿ incorporated into a complementary sample holder will couple with this manipulator, allowing crystal samples to be remotely loaded and unloaded using industrial robotics. Phase I will establish feasibility by creating a prototype positioning system and gauging its ability to securely register incoming crystals and to accurately and rapidly align them within a cryostat. Techniques for determining the exact location of a crystal relative to the neutron beam, when hidden from direct view, will be determined. Commercial Applications and Other Benefits as described by the awardee: The Compact Sample Positioning System should provide a powerful enabling technology for the SNS and other neutron science facilities. A small, high-precision positioning device also should have broad commercial relevance beyond neutron science. Potential applications include the remote adjustment of critical optical components used in X-ray crystallography, semiconductor photomask etching, and electron beam lithography.