Optimization of moderators and beam extraction at the ESS
(2018) In Journal of Applied Crystallography 51(2). p.264-281- Abstract
A global approach coupling the moderator to the beam extraction system has been applied for the design optimization of the thermal and cold moderators of the European Spallation Source (ESS), which will be the brightest neutron source in the world for condensed-matter studies. The design is based on the recently developed high-brightness low-dimensional moderator concepts. Para-hydrogen is used for the cold neutron source, while thermal neutrons are provided by moderation in water. The overall moderation configuration was chosen in order to satisfy a range of requirements on bispectral extraction, beamport configuration and instrument performance. All instruments are served by a single moderator assembly above the target, arranged in a... (More)
A global approach coupling the moderator to the beam extraction system has been applied for the design optimization of the thermal and cold moderators of the European Spallation Source (ESS), which will be the brightest neutron source in the world for condensed-matter studies. The design is based on the recently developed high-brightness low-dimensional moderator concepts. Para-hydrogen is used for the cold neutron source, while thermal neutrons are provided by moderation in water. The overall moderation configuration was chosen in order to satisfy a range of requirements on bispectral extraction, beamport configuration and instrument performance. All instruments are served by a single moderator assembly above the target, arranged in a 'butterfly' geometry with a height of 3 cm. This was determined to be the optimal height for trade-off between high brightness and efficient guide illumination, by analysis of the performance of 23 instruments, based on the reference suite of the ESS Technical Design Report. The concept of 'brilliance transfer' is introduced to quantify the performance of the neutron optical system from the source to the sample. The target monolith incorporates a grid of 42 neutron beamports with an average separation of 6°, allowing a free choice between cold and thermal neutron sources at all instrument positions. With the large number of beamports and the space below the target available for future moderators, ample opportunities are available for future upgrades.
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- author
- Andersen, Ken Holst LU ; Bertelsen, Mads ; Zanini, Luca LU ; Klinkby, Esben Bryndt ; Schönfeldt, Troels ; Bentley, Phillip Martin LU and Saroun, Jan
- organization
- publishing date
- 2018-04-01
- type
- Contribution to journal
- publication status
- published
- subject
- keywords
- brilliance transfer, butterfly moderators, low-dimensional moderators, neutron instruments, pancake moderators, para-hydrogen moderators, water moderators
- in
- Journal of Applied Crystallography
- volume
- 51
- issue
- 2
- pages
- 18 pages
- publisher
- International Union of Crystallography
- external identifiers
-
- scopus:85045064847
- pmid:29657564
- ISSN
- 0021-8898
- DOI
- 10.1107/S1600576718002406
- language
- English
- LU publication?
- yes
- id
- ab0cb2ab-36d9-41f3-9324-1b712dbaf4e4
- date added to LUP
- 2018-04-19 15:58:17
- date last changed
- 2024-06-11 14:12:46
@article{ab0cb2ab-36d9-41f3-9324-1b712dbaf4e4,
abstract = {{<p>A global approach coupling the moderator to the beam extraction system has been applied for the design optimization of the thermal and cold moderators of the European Spallation Source (ESS), which will be the brightest neutron source in the world for condensed-matter studies. The design is based on the recently developed high-brightness low-dimensional moderator concepts. Para-hydrogen is used for the cold neutron source, while thermal neutrons are provided by moderation in water. The overall moderation configuration was chosen in order to satisfy a range of requirements on bispectral extraction, beamport configuration and instrument performance. All instruments are served by a single moderator assembly above the target, arranged in a 'butterfly' geometry with a height of 3 cm. This was determined to be the optimal height for trade-off between high brightness and efficient guide illumination, by analysis of the performance of 23 instruments, based on the reference suite of the ESS Technical Design Report. The concept of 'brilliance transfer' is introduced to quantify the performance of the neutron optical system from the source to the sample. The target monolith incorporates a grid of 42 neutron beamports with an average separation of 6°, allowing a free choice between cold and thermal neutron sources at all instrument positions. With the large number of beamports and the space below the target available for future moderators, ample opportunities are available for future upgrades.</p>}},
author = {{Andersen, Ken Holst and Bertelsen, Mads and Zanini, Luca and Klinkby, Esben Bryndt and Schönfeldt, Troels and Bentley, Phillip Martin and Saroun, Jan}},
issn = {{0021-8898}},
keywords = {{brilliance transfer; butterfly moderators; low-dimensional moderators; neutron instruments; pancake moderators; para-hydrogen moderators; water moderators}},
language = {{eng}},
month = {{04}},
number = {{2}},
pages = {{264--281}},
publisher = {{International Union of Crystallography}},
series = {{Journal of Applied Crystallography}},
title = {{Optimization of moderators and beam extraction at the ESS}},
url = {{http://dx.doi.org/10.1107/S1600576718002406}},
doi = {{10.1107/S1600576718002406}},
volume = {{51}},
year = {{2018}},
}