CCLRC Facilities Development Project FDPG/020
Towards enhanced instrument performance using compact focusing devices
Dr D A Keen et al (2004-2006)
Project Objectives:
1. To design and manufacture mountings for compact neutron focusing devices that will provide precise, remotely operated device alignment in the neutron beam.
2. To test a small number of compact focusing devices to assess their impact on neutron flux, resolution and background and to compare these results with anticipated performance based on Monte Carlo modelling.
3. To install an optimised compact focusing device effectively on SXD.
4. To initiate projects for the installation of optimised compact focusing devices on other ISIS instruments, as required.
Project Summary:
Many areas of neutron scattering science are moving towards experiments that rely on high quality results from samples traditionally believed to be too small for neutron scattering. Examples of this are single crystal diffraction from increasingly complex structures, powder diffraction in extreme environments and surface scattering from low scattering thin films. Although much work has been done to reduce backgrounds and increase detector solid angle on recently commissioned instruments (e.g. SXD, GEM and PEARL at ISIS) and new facilities (e.g. TS-II at ISIS and SNS in the United States) will provide increased flux, there has been little attention paid to the potential gains from neutron focusing. Theoretically, compact focusing devices mounted on existing instruments at ISIS can deliver more than an order of magnitude gain in neutron flux on a small sample in the longer wavelength regime. This clearly attractive potential has not, to date, been realised in practice. This proposal requests funds to develop focusing devices at ISIS, to validate their operating parameters experimentally and to initiate a programme for installing them on a number of existing instruments. This will not only benefit these instruments, but will also provide vital parameters for those planning future instruments on TS-II and elsewhere.
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