POWGEN: a third-generation high resolution high-throughput powder diffraction instrument at the Spallation Neutron Source

Abstract

Powgen represents a departure from previous designs for a time-of-flight powder diffractometer at a spallation neutron source and may be considered a third-generation design. The instrument is optimized for both parametric studies of materials under a wide range of conditions (T, P, H, flowing gases, etc) and ab-initio crystal structure determinations of complex solid-state materials with asymmetric unit-cells of the order {approx}1500 {angstrom}{sup 3}. The geometric design of the instrument allows for all detected scattered neutrons to be focused onto a single diffraction profile yielding high count rate while preserving good resolution {Delta}d/d = 0.0015 at a d = 1 {angstrom}.