Using Convergent Beams for Small-Sample, Time-of-Flight Neutron Diffraction

70146 Currently, large crystals and long measurement times are required for neutron diffraction measurements, used in materials science research. The use of convergent beam diffraction could significantly reduce both crystal size and measurement time for otherwise impractical neutron diffraction measurements such as protein structure, high pressure phase studies, and magnetic structure studies, as well as for strain, composition, and texture mapping of inhomogeneous samples. This project will develop technology for focusing neutron beams with polycapillary optics, providing greatly increased intensity and increased reciprocal phase space, and allowing the use of small pressure- and temperature-controlled samples. The measurements also will provide the basis for convergent beam neutron diffraction for future pulsed neutron sources for small sample biological macromolecular crystallography. Phase I will design and fabricate the polycapillary focusing optics so as to be, suitable for convergent beam crystallography for the Single Crystal Diffraction (SCD) and the General Purpose Powder Diffraction (GPPD) instruments at the Intense Pulsed Neutron Source at Argonne National Laboratory. The optics will be characterized with x-rays and with neutrons on SCD and GPPD for diffraction measurements with selected crystals. Commercial Applications and Other Benefits as described by the awardee: A compact convergent beam diffraction system that provides shorter evaluation times and smaller sample requirements should lead to faster development cycles for new drugs and other materials. Not only would neutron beam lines be a targeted market, but also the new optics would be applicable to x-ray diffraction.