Characterisation of the position-sensitive 3He-detector system of the BIFROST instrument at ESS
(2024) FYSM63 20232Department of Physics
Particle and nuclear physics
- Abstract
- This scientific thesis focuses on the characterisation of the 3He-detector system of the BIFROST instrument under construction on the European Spallation Source. To that end, the position-sensitive 3He proportional counters that make up the detector system was subjected to a factory acceptance test performed at Laboratoire Léon Brillouin Saclay, France. The purpose of this is to prove that the overall performance of the 3He-detector system meets the imposed requirements of the planned scientific studies that will utilise the BIFROST instrument. With the experimental results of the factory acceptance test as a foundation, the goals of this thesis work therefore is to first validate the read-out system, and subsequently, to characterise the... (More)
- This scientific thesis focuses on the characterisation of the 3He-detector system of the BIFROST instrument under construction on the European Spallation Source. To that end, the position-sensitive 3He proportional counters that make up the detector system was subjected to a factory acceptance test performed at Laboratoire Léon Brillouin Saclay, France. The purpose of this is to prove that the overall performance of the 3He-detector system meets the imposed requirements of the planned scientific studies that will utilise the BIFROST instrument. With the experimental results of the factory acceptance test as a foundation, the goals of this thesis work therefore is to first validate the read-out system, and subsequently, to characterise the position reconstruction performance of the detector system. The factory acceptance test consisted of separate neutron measurements with the three configurations that make up the BIFROST detector system. In each measurement, the 3He proportional counters were covered with slitted cadmium masks, before being illuminated by an Am/Be neutron source. The analysis of these measurements yielded the position reconstruction resolution and intrinsic spatial resolution of the 3He-detector system. These resolution results will serve as a benchmark during the commissioning phase of the BIFROST instrument, and for monitoring possible deterioration in the performance of the detector and associated read-out electronics due to long-term operation in high neutron fields. (Less)
- Popular Abstract
- How well do you know your neutron detector?
Neutrons, together with protons and electrons, form the building block of the universe: atoms. By itself, neutrons can be used in a multitude of scientific research fields such as materials and life sciences. There are different ways to produce these free neutrons, but the way the upcoming European Spallation Source (ESS) research facility produces large amounts of neutrons (∼1015 neutrons/second/cm2) is by a spallation reaction. The spallation reaction can be understood by considering the opening shot in a game of billiard, where the cue ball breaks the rack of object balls with both speed and strength. Here, the object balls represent the neutrons. To study the samples that we are interested... (More) - How well do you know your neutron detector?
Neutrons, together with protons and electrons, form the building block of the universe: atoms. By itself, neutrons can be used in a multitude of scientific research fields such as materials and life sciences. There are different ways to produce these free neutrons, but the way the upcoming European Spallation Source (ESS) research facility produces large amounts of neutrons (∼1015 neutrons/second/cm2) is by a spallation reaction. The spallation reaction can be understood by considering the opening shot in a game of billiard, where the cue ball breaks the rack of object balls with both speed and strength. Here, the object balls represent the neutrons. To study the samples that we are interested in, we let the free neutrons interact with it, and thereafter investigate how the neutrons have changed. But how do we actually “see” these neutrons? That’s where a neutron detector comes in!
A neutron detector provides information of the neutrons indirectly, that is, by measuring the radiation created when the neutrons interact with the detector. For the BIFROST instrument at ESS, position-sensitive 3He neutron detectors will be used. These detectors both count the number of neutrons that have interacted with the detector (number of events) and also give the position of where the interaction occurred in the detector. But then comes the question, to what extent can we trust the position information provided by the detector? To find out, we subjected the detector system to a factory acceptance test at the Laboratoire Léon Brillouin in Saclay, France using a portable neutron source. By exposing free neutrons to small defined regions of the detector and taking measurements, we are able to find out the resolution of these detectors, that is, how well the detector is able to differentiate between the positions of two separate neutron interactions.
In the larger picture, these resolution results will provide a benchmark for when the BIFROST instrument is installed and operational at ESS, and will serve to monitor the long-term performance of the detectors when subjected to the anticipated strongest neutron source in the world that is the ESS facility. (Less)
Please use this url to cite or link to this publication:
http://lup.lub.lu.se/student-papers/record/9147539
- author
- Ti, Auden LU
- supervisor
- organization
- course
- FYSM63 20232
- year
- 2024
- type
- H1 - Master's Degree (One Year)
- subject
- keywords
- neutron, neutron detection, position resolution, position calibration, ESS, instrument, BIFROST, Detector Group
- language
- English
- id
- 9147539
- date added to LUP
- 2024-04-03 11:37:46
- date last changed
- 2024-04-03 11:37:46
@misc{9147539,
abstract = {{This scientific thesis focuses on the characterisation of the 3He-detector system of the BIFROST instrument under construction on the European Spallation Source. To that end, the position-sensitive 3He proportional counters that make up the detector system was subjected to a factory acceptance test performed at Laboratoire Léon Brillouin Saclay, France. The purpose of this is to prove that the overall performance of the 3He-detector system meets the imposed requirements of the planned scientific studies that will utilise the BIFROST instrument. With the experimental results of the factory acceptance test as a foundation, the goals of this thesis work therefore is to first validate the read-out system, and subsequently, to characterise the position reconstruction performance of the detector system. The factory acceptance test consisted of separate neutron measurements with the three configurations that make up the BIFROST detector system. In each measurement, the 3He proportional counters were covered with slitted cadmium masks, before being illuminated by an Am/Be neutron source. The analysis of these measurements yielded the position reconstruction resolution and intrinsic spatial resolution of the 3He-detector system. These resolution results will serve as a benchmark during the commissioning phase of the BIFROST instrument, and for monitoring possible deterioration in the performance of the detector and associated read-out electronics due to long-term operation in high neutron fields.}},
author = {{Ti, Auden}},
language = {{eng}},
note = {{Student Paper}},
title = {{Characterisation of the position-sensitive 3He-detector system of the BIFROST instrument at ESS}},
year = {{2024}},
}