High-Pressure-Preferred Orientation | HIPPO

Materials in Extreme Environments and Geoscience

HIPPO is the first third-generation neutron time-of-flight powder diffractometer constructed in the United States. It achieves very high neutron count rates by virtue of a short (9 m) initial flight path on a high-intensity water moderator and 1,360 3He detector tubes covering 4.8 m2 of detector area from 10° to 150° in scattering angles.

HIPPO was designed and manufactured as a joint effort between LANSCE and the University of California with the goal of doing world-class science by making neutron powder diffractometry an accessible tool to the national user community. D-spacing ranges from 0.12-4.80 Å (1.31-52.4 Å-1) to 1.2-47.5 Å (0.13-5.3 Å-1) are available to support studies of crystal orientation distribution (texture), amorphous solids, liquids, magnetic diffraction, small crystalline samples, and samples subjected to non-ambient environments such as temperature, pressure, or govuni-axial stress.

The exceptionally high data rates of HIPPO also make it useful for time-resolved studies. In addition to the standard ancillary equipment (100-specimen sample changer, closed-cycle He refrigerator, furnace), HIPPO has unique high-pressure anvil cells capable of achieving pressures of 30 GPa at ambient and high (2000 K) temperatures with samples up to 100 mm3 in volume. A low-temperature gas cell allows studies in the pressure range up to 5 kbar and temperatures between10K and ambient for instance, to study clathrates. The uni-axial stress-rig CRATES, built by the Technical University Hamburg-Harburg, Germany, allows the study of crystal lattice strains and texture changes in situ during deformation. HIPPO's sample chamber also accomodates user-provided sample environments.