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Design, Construction and Characterization of a Portable Fast-Neutron Detector

Mauritzsson, Nicholai LU (2017) FYSM60 20171
Department of Physics
Nuclear physics
Abstract
At European Spallation Source ERIC, 2 GeV proton bunches will be accelerated towards a tungsten target where spallation will occur, producing a wide neutron energy spectrum. Despite the shielding and moderators in place to stop and/or reduce their energy, a significant portion of the most energetic neutrons, called prompt neutrons, might still reach the sample position of a neutron-scattering instrument. It has been previously shown that these prompt neutrons contribute to a degradation of the signal-to-noise ratio of the detectors. Clearly, a tool for identifying sources of fast-neutron background would be very valuable. The design goals of the envisioned Portable Fast-Neutron Diagnostic Detector include portability, durability, fast... (More)
At European Spallation Source ERIC, 2 GeV proton bunches will be accelerated towards a tungsten target where spallation will occur, producing a wide neutron energy spectrum. Despite the shielding and moderators in place to stop and/or reduce their energy, a significant portion of the most energetic neutrons, called prompt neutrons, might still reach the sample position of a neutron-scattering instrument. It has been previously shown that these prompt neutrons contribute to a degradation of the signal-to-noise ratio of the detectors. Clearly, a tool for identifying sources of fast-neutron background would be very valuable. The design goals of the envisioned Portable Fast-Neutron Diagnostic Detector include portability, durability, fast response and the ability for performing self-triggering time-of-flight measurements complete with tracking to localize fast-neutron sources. Within the context of this thesis, the detector system was conceptualized, designed and a prototype assembled. Testing was carried out with a plutonium/beryllium source and a industry-standard liquid scintillator detector to define a tagged fast-neutron beam (2.8-6.3 MeV). It was shown that the neutron response is energy dependent and improves at lower energies. Fast-neutron tracking capabilities of the detector were demonstrated. (Less)
Popular Abstract (Swedish)
Spallations anläggningar är ämnade för produktion och forskning med fria neutroner. Ett problem uppstår för dessa anläggningar efter att högenergetiska neutroner skapas via en så kallad spallation. Högenergetiska neutroner är problematiska att hålla udner kontroll. På grund av deras höga energi kan dessa neutronerna ``rymma'' och orsaka kärnreaktioner som bidrar till en försvagad signal-upplösningen hos forsknings-instrumenten på dessa anläggningarna. Detta projekt behandlar utvecklingen av ett diagnos instrument som kan titta på just dessa högenergetiska neutroner. Instrumentet kan sedan användas av spallations anläggningarna för att kartlägga sina snabba neutroner som rymt.
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author
Mauritzsson, Nicholai LU
supervisor
organization
course
FYSM60 20171
year
type
H2 - Master's Degree (Two Years)
subject
keywords
fast-neutrons, detector, plastic scintillator, NE110, neutron tracking, scintillation, spallation, european spallation source, sonnig
language
English
id
8910537
date added to LUP
2017-06-09 12:49:30
date last changed
2017-06-09 12:49:30
@misc{8910537,
  abstract     = {At European Spallation Source ERIC, 2 GeV proton bunches will be accelerated towards a tungsten target where spallation will occur, producing a wide neutron energy spectrum. Despite the shielding and moderators in place to stop and/or reduce their energy, a significant portion of the most energetic neutrons, called prompt neutrons, might still reach the sample position of a neutron-scattering instrument. It has been previously shown that these prompt neutrons contribute to a degradation of the signal-to-noise ratio of the detectors. Clearly, a tool for identifying sources of fast-neutron background would be very valuable. The design goals of the envisioned Portable Fast-Neutron Diagnostic Detector include portability, durability, fast response and the ability for performing self-triggering time-of-flight measurements complete with tracking to localize fast-neutron sources. Within the context of this thesis, the detector system was conceptualized, designed and a prototype assembled. Testing was carried out with a plutonium/beryllium source and a industry-standard liquid scintillator detector to define a tagged fast-neutron beam (2.8-6.3 MeV). It was shown that the neutron response is energy dependent and improves at lower energies. Fast-neutron tracking capabilities of the detector were demonstrated.},
  author       = {Mauritzsson, Nicholai},
  keyword      = {fast-neutrons,detector,plastic scintillator,NE110,neutron tracking,scintillation,spallation,european spallation source,sonnig},
  language     = {eng},
  note         = {Student Paper},
  title        = {Design, Construction and Characterization of a Portable Fast-Neutron Detector},
  year         = {2017},
}