Design of a high resolution time-of-flight crystal analyser spectrometer and hydrogen diffusion in intermetallic compounds

Campbell, SI

Abstract

The main part of this thesis concerns the design and simulation of a polarization
analysis backscattering cold neutron spectrometer, OSIRIS, at the ISIS pulsed
neutron source. The OSIRIS instrument consists of two parts, a high-resolution
powder diffractometer and a micro-eV resolution inelastic spectrometer. The
incident cold neutron beam has the option of being polarised by means of a series
of interchangeable polarising benders. The inelastic spectrometer consists of an
analyser array constructed from pyrolytic graphite crystals situated in nearbackscattering
geometry. Monte Carlo simulations have been performed in order
to optimise and investigate various components of the spectrometer, including
the guide, polarisers and analyser.
A microguide testing device, MITED, has been constructed, commissioned and,
using it, measurements have been made on neutron guide sections. This
instrument has also been used to test the reflectivity of supermirror coated guide
sections.
Originally, it was the aim of this thesis to carry out all the scientific
commissioning experiments required for OSIRIS. This has become unfeasible
due to manpower problems within the ISIS facility, which have delayed the
construction of the OSIRIS spectrometer and have moved it out of the time range
of this thesis.
Therefore an extra section of work has been included, on a family of intermetallic
metal hydride systems that it will be of interest to investigate using the OSIRIS
instrument.
A general study of the diffusion of hydrogen in C15 Laves phase intermetallic
compounds has been performed. This has employed the techniques of quasielastic
neutron scattering, inelastic vibrational spectroscopy, diffraction and
muon spectroscopy.

Citation

Campbell, S. Design of a high resolution time-of-flight crystal analyser spectrometer and hydrogen diffusion in intermetallic compounds. (Thesis). University of Salford

• Thesis Type: Thesis
• Deposit Date: May 17, 2010
• Publicly Available Date: May 17, 2010
• Award Date: Sep 1, 1998