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Systematic performance study of common neutron guide geometries

Kleno, Kaspar Hewitt; Lieutenant, Klaus; Andersen, Ken LU and Lefmann, Kim (2012) In Nuclear Instruments & Methods in Physics Research. Section A: Accelerators, Spectrometers, Detectors, and Associated Equipment 696. p.75-84
Abstract
In this report, we present the results from a systematic benchmarking of four different long neutron guide geometries: elliptic, parabolic, ballistic (piecewise linearly focusing/defocusing), and straight, for various wavelength, divergence restriction, and guide length settings. In this work, we mapped relevant parts of the neutron phase space to show where advanced guide geometries have significant transport advantages over simple guide geometries. The primary findings are that the elliptic and parabolic geometries perform almost equally well, and they are considerably superior to the other geometries, except for low-divergence, cold neutrons. In addition, it was observed that transporting thermal neutrons more than 100 m using elliptic... (More)
In this report, we present the results from a systematic benchmarking of four different long neutron guide geometries: elliptic, parabolic, ballistic (piecewise linearly focusing/defocusing), and straight, for various wavelength, divergence restriction, and guide length settings. In this work, we mapped relevant parts of the neutron phase space to show where advanced guide geometries have significant transport advantages over simple guide geometries. The primary findings are that the elliptic and parabolic geometries perform almost equally well, and they are considerably superior to the other geometries, except for low-divergence, cold neutrons. In addition, it was observed that transporting thermal neutrons more than 100 m using elliptic guides was possible with only a 10% loss in the phase space density for divergences up to +/- 0.5 degrees, which enables the construction of very long thermal neutron instruments. Our work will allow instrument designers to use tabulated, standard geometries as a starting point for optimising the guide required for the particular instrument. (C) 2012 Elsevier B.V. All rights reserved. (Less)
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author
organization
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Contribution to journal
publication status
published
subject
keywords
Neutron guides, Ray tracing, Monte Carlo, Neutron scattering, European, Spallation Source, Elliptic guides
in
Nuclear Instruments & Methods in Physics Research. Section A: Accelerators, Spectrometers, Detectors, and Associated Equipment
volume
696
pages
75 - 84
publisher
Elsevier
external identifiers
  • wos:000311570900007
  • scopus:84866511766
ISSN
0167-5087
DOI
10.1016/j.nima.2012.08.027
language
English
LU publication?
yes
id
c5315039-55c5-4383-8cc0-ec30375dbd94 (old id 3372550)
date added to LUP
2013-01-31 12:07:41
date last changed
2017-07-23 03:58:31
@article{c5315039-55c5-4383-8cc0-ec30375dbd94,
  abstract     = {In this report, we present the results from a systematic benchmarking of four different long neutron guide geometries: elliptic, parabolic, ballistic (piecewise linearly focusing/defocusing), and straight, for various wavelength, divergence restriction, and guide length settings. In this work, we mapped relevant parts of the neutron phase space to show where advanced guide geometries have significant transport advantages over simple guide geometries. The primary findings are that the elliptic and parabolic geometries perform almost equally well, and they are considerably superior to the other geometries, except for low-divergence, cold neutrons. In addition, it was observed that transporting thermal neutrons more than 100 m using elliptic guides was possible with only a 10% loss in the phase space density for divergences up to +/- 0.5 degrees, which enables the construction of very long thermal neutron instruments. Our work will allow instrument designers to use tabulated, standard geometries as a starting point for optimising the guide required for the particular instrument. (C) 2012 Elsevier B.V. All rights reserved.},
  author       = {Kleno, Kaspar Hewitt and Lieutenant, Klaus and Andersen, Ken and Lefmann, Kim},
  issn         = {0167-5087},
  keyword      = {Neutron guides,Ray tracing,Monte Carlo,Neutron scattering,European,Spallation Source,Elliptic guides},
  language     = {eng},
  pages        = {75--84},
  publisher    = {Elsevier},
  series       = {Nuclear Instruments & Methods in Physics Research. Section A: Accelerators, Spectrometers, Detectors, and Associated Equipment},
  title        = {Systematic performance study of common neutron guide geometries},
  url          = {http://dx.doi.org/10.1016/j.nima.2012.08.027},
  volume       = {696},
  year         = {2012},
}