Article ID | Journal | Published Year | Pages | File Type |
---|---|---|---|---|
10715808 | Nuclear Instruments and Methods in Physics Research Section A: Accelerators, Spectrometers, Detectors and Associated Equipment | 2011 | 6 Pages |
Abstract
The triple monochromator for the TOF neutron spectrometer Pelican at ANSTO has been fully optimised in terms of overall performance, including the determination of the thickness of the pyrolytic graphite crystals. A total of 24 composite crystals were designed and fabricated. The calculated optimum thickness of 1.3Â mm and the length of 15Â cm of the monochromator crystals, that are not available commercially, were obtained by cleaving and soldering with indium. An extensive characterisation of the crystals using X-ray and neutron diffraction was conducted before and after the cleaving and bonding processes. The results proved that no damage was introduced during fabrication and showed that the design goals were fully met. The measured peak reflectivity and rocking curve widths were indeed in an excellent agreement with theory. In addition to the superior efficiency of the triple monochromator achieved by this novel approach, the amount of the crystal material required could be reduced by 1/3.
Related Topics
Physical Sciences and Engineering
Physics and Astronomy
Instrumentation
Authors
A.K. Freund, D.H. Yu,