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Neutron guide-split: A high performance guide bundle concept for elliptical guides

Holm, Sonja L.; Rasmussen, Nina; Hopfner, Louise; Bertelsen, Mads; Voigt, Joerg; Andersen, Ken LU and Lefmann, Kim (2015) In Nuclear Instruments & Methods in Physics Research. Section A: Accelerators, Spectrometers, Detectors, and Associated Equipment 782. p.1-8
Abstract
We present a new guide-split concept for transporting cold and thermal neutrons to multiple instruments from a single beam port at a neutron facility without compromising the useful neutron brilliance notably for any of the instruments. Elliptical guides are capable of transporting an almost completely filled phase space within a large divergence (+/- 2 degrees for cold neutrons). It is therefore possible to place several secondary guides side by side pointing in slightly different directions using the end of a primary guide as a virtual source. The instruments placed at the secondary guides hence exploit different parts of the phase space transported by the primary guide. In addition, the resulting kink between the primary and secondary... (More)
We present a new guide-split concept for transporting cold and thermal neutrons to multiple instruments from a single beam port at a neutron facility without compromising the useful neutron brilliance notably for any of the instruments. Elliptical guides are capable of transporting an almost completely filled phase space within a large divergence (+/- 2 degrees for cold neutrons). It is therefore possible to place several secondary guides side by side pointing in slightly different directions using the end of a primary guide as a virtual source. The instruments placed at the secondary guides hence exploit different parts of the phase space transported by the primary guide. In addition, the resulting kink between the primary and secondary guide eliminates line of sight. Using ray-tracing simulations of three different set-ups (with two, four, and eight secondary guides) we show that it is possible to illuminate at least eight sample positions from one beam port with a brilliance transfer above 90% on each sample on a 150 m long instrument. This has been clone for a phase space volume comprised of an area of 1 x 1 cm(2) and a maximum divergence of +/- 0.5 degrees within a wavelength band of 425-5.75 angstrom. We show, by a full virtual experiment, an example of applying the guide-split concept to an instrument proposed for the European Spallation Source, namely a magnetism diffractometer. (C) 2015 Elsevier B.V. All rights reserved, (Less)
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author
organization
publishing date
type
Contribution to journal
publication status
published
subject
keywords
McStas, Monte Carlo, Ray tracing, Neutron guide, ESS
in
Nuclear Instruments & Methods in Physics Research. Section A: Accelerators, Spectrometers, Detectors, and Associated Equipment
volume
782
pages
1 - 8
publisher
Elsevier
external identifiers
  • wos:000351065600001
  • scopus:84923380371
ISSN
0167-5087
DOI
10.1016/j.nima.2015.01.045
language
English
LU publication?
yes
id
c4605a2d-90f8-40ee-ab49-e32cf9409f36 (old id 5281778)
date added to LUP
2015-04-24 11:59:44
date last changed
2017-01-01 05:20:21
@article{c4605a2d-90f8-40ee-ab49-e32cf9409f36,
  abstract     = {We present a new guide-split concept for transporting cold and thermal neutrons to multiple instruments from a single beam port at a neutron facility without compromising the useful neutron brilliance notably for any of the instruments. Elliptical guides are capable of transporting an almost completely filled phase space within a large divergence (+/- 2 degrees for cold neutrons). It is therefore possible to place several secondary guides side by side pointing in slightly different directions using the end of a primary guide as a virtual source. The instruments placed at the secondary guides hence exploit different parts of the phase space transported by the primary guide. In addition, the resulting kink between the primary and secondary guide eliminates line of sight. Using ray-tracing simulations of three different set-ups (with two, four, and eight secondary guides) we show that it is possible to illuminate at least eight sample positions from one beam port with a brilliance transfer above 90% on each sample on a 150 m long instrument. This has been clone for a phase space volume comprised of an area of 1 x 1 cm(2) and a maximum divergence of +/- 0.5 degrees within a wavelength band of 425-5.75 angstrom. We show, by a full virtual experiment, an example of applying the guide-split concept to an instrument proposed for the European Spallation Source, namely a magnetism diffractometer. (C) 2015 Elsevier B.V. All rights reserved,},
  author       = {Holm, Sonja L. and Rasmussen, Nina and Hopfner, Louise and Bertelsen, Mads and Voigt, Joerg and Andersen, Ken and Lefmann, Kim},
  issn         = {0167-5087},
  keyword      = {McStas,Monte Carlo,Ray tracing,Neutron guide,ESS},
  language     = {eng},
  pages        = {1--8},
  publisher    = {Elsevier},
  series       = {Nuclear Instruments & Methods in Physics Research. Section A: Accelerators, Spectrometers, Detectors, and Associated Equipment},
  title        = {Neutron guide-split: A high performance guide bundle concept for elliptical guides},
  url          = {http://dx.doi.org/10.1016/j.nima.2015.01.045},
  volume       = {782},
  year         = {2015},
}