In situ deformation apparatus for time-of-flight neutron diffraction:Texture development of polycrystalline ice Ih

Abstract

This article documents a new in situ deformation apparatus built for neutron diffraction investigations of polycrystalline materials in low-temperature environments and the first experiment in which it was used. We performed texture analysis of fine-grained polycrystalline D2O ice Ih deformed uniaxially between 230 and 240K using time-of-flight neutron diffraction on the high-pressure preferred orientation diffractometer at the Manuel Lujan, Jr. Neutron Scattering Center at Los Alamos National Laboratory. The new deformation apparatus operates at 1atm of ambient pressure and over temperatures in the range of 77K<T<298K, and accommodates up to 667N of uniaxially applied load. It is suitable for diffraction studies of any bulk polycrystalline material, ideally cylindrical in shape, and is adaptable to multiple neutron spectrometers, including those at other polychromatic and monochromatic neutron facilities. The first experiment on a hexagonal ice sample demonstrates development of fiber texture in the direction of the applied load. The equipment has many applications to earth science, glaciology, and ice engineering.