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Study of neutron shielding collimators for curved beamlines at the European Spallation Source

Santoro, V. LU ; Dijulio, D. D. LU ; Ansell, S. LU ; Cherkashyna, N. LU ; Muhrer, G. and Bentley, P. M. LU (2018) 4th International Workshop on Accelerator Radiation Induced Activation, ARIA 2017 In Journal of Physics: Conference Series 1046.
Abstract

The European Spallation Source is being constructed in Lund, Sweden and is planned to be the world's brightest pulsed spallation neutron source for cold and thermal neutron beams (≤ 1 eV). The facility uses a 2 GeV proton beam to produce neutrons from a tungsten target. The neutrons are then moderated in a moderator assembly consisting of both liquid hydrogen and water compartments. Surrounding the moderator are 22 beamports, which view the moderator's outside surfaces. The beamports are connected to long neutron guides that transport the moderated neutrons to the sample position via reflections. As well as the desired moderated neutrons, fast neutrons coming directly from the target can find their way down the beamlines. These can... (More)

The European Spallation Source is being constructed in Lund, Sweden and is planned to be the world's brightest pulsed spallation neutron source for cold and thermal neutron beams (≤ 1 eV). The facility uses a 2 GeV proton beam to produce neutrons from a tungsten target. The neutrons are then moderated in a moderator assembly consisting of both liquid hydrogen and water compartments. Surrounding the moderator are 22 beamports, which view the moderator's outside surfaces. The beamports are connected to long neutron guides that transport the moderated neutrons to the sample position via reflections. As well as the desired moderated neutrons, fast neutrons coming directly from the target can find their way down the beamlines. These can create unwanted sources of background for the instruments. To mitigate such a kind of background, several instruments will use curved guides to lose direct line-of-sight (LoS) to the moderator and the target. In addition instruments can also use shielding collimators to reduce the amount of fast neutrons further traveling down the guide due to albedo reflections or streaming. Several different materials have been proposed for this purpose. We present the results of a study of different options for collimators and identify the optimal choices that balance cost, background and activation levels.

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Please use this url to cite or link to this publication:
author
organization
publishing date
type
Chapter in Book/Report/Conference proceeding
publication status
published
host publication
Journal of Physics: Conference Series
series title
Journal of Physics: Conference Series
volume
1046
conference name
4th International Workshop on Accelerator Radiation Induced Activation, ARIA 2017
conference location
Lund, Sweden
conference dates
2017-05-22 - 2017-05-24
external identifiers
  • scopus:85049556058
ISSN
1742-6588
DOI
10.1088/1742-6596/1046/1/012010
language
English
LU publication?
yes
id
03edb5b2-a63c-4e12-a8f8-72fd86df4bb1
date added to LUP
2018-07-25 10:19:38
date last changed
2019-02-20 11:22:58
@inproceedings{03edb5b2-a63c-4e12-a8f8-72fd86df4bb1,
  abstract     = {<p>The European Spallation Source is being constructed in Lund, Sweden and is planned to be the world's brightest pulsed spallation neutron source for cold and thermal neutron beams (≤ 1 eV). The facility uses a 2 GeV proton beam to produce neutrons from a tungsten target. The neutrons are then moderated in a moderator assembly consisting of both liquid hydrogen and water compartments. Surrounding the moderator are 22 beamports, which view the moderator's outside surfaces. The beamports are connected to long neutron guides that transport the moderated neutrons to the sample position via reflections. As well as the desired moderated neutrons, fast neutrons coming directly from the target can find their way down the beamlines. These can create unwanted sources of background for the instruments. To mitigate such a kind of background, several instruments will use curved guides to lose direct line-of-sight (LoS) to the moderator and the target. In addition instruments can also use shielding collimators to reduce the amount of fast neutrons further traveling down the guide due to albedo reflections or streaming. Several different materials have been proposed for this purpose. We present the results of a study of different options for collimators and identify the optimal choices that balance cost, background and activation levels.</p>},
  author       = {Santoro, V. and Dijulio, D. D. and Ansell, S. and Cherkashyna, N. and Muhrer, G. and Bentley, P. M.},
  booktitle    = {Journal of Physics: Conference Series},
  issn         = {1742-6588},
  language     = {eng},
  location     = {Lund, Sweden},
  month        = {06},
  title        = {Study of neutron shielding collimators for curved beamlines at the European Spallation Source},
  url          = {http://dx.doi.org/10.1088/1742-6596/1046/1/012010},
  volume       = {1046},
  year         = {2018},
}