Advanced

Development of a Detector System for Detection of Thermal Neutrons from Spent Nuclear Fuel

Söderström, Daniel LU (2016) PHYM01 20161
Nuclear physics
Department of Physics
Abstract
The nuclear reaction 10B(n,alpha)7Li* was utilised to develop a neutron detection system. This system has the purpose of being used to detect the thermal neutron radiation emitted by spent nuclear fuel, before it is transported to a final repository. This to investigate the content of the fuel-containing capsules, primarily to ensure non-proliferation of radioactive materials in the nuclear waste management process.

The investigated detector system utilises two scintillators mounted on one photomultiplier tube (PMT). One of them boron loaded to be sensitive to neutrons, and the other sensitive to gamma radiation to detect the de-excitation quanta released by the lithium ion, often left in an excited state after the 10B(n,alpha)7Li*... (More)
The nuclear reaction 10B(n,alpha)7Li* was utilised to develop a neutron detection system. This system has the purpose of being used to detect the thermal neutron radiation emitted by spent nuclear fuel, before it is transported to a final repository. This to investigate the content of the fuel-containing capsules, primarily to ensure non-proliferation of radioactive materials in the nuclear waste management process.

The investigated detector system utilises two scintillators mounted on one photomultiplier tube (PMT). One of them boron loaded to be sensitive to neutrons, and the other sensitive to gamma radiation to detect the de-excitation quanta released by the lithium ion, often left in an excited state after the 10B(n,alpha)7Li* reaction. The detection of these signals together reduces background noise, and those signals of interest are extracted from the others by a pulse shape discrimination scheme.

The possibility to read out the scintillator signals using an avalanche photodiode (APD) was also investigated. Inherent noise difficulties and poorly matched properties of scintillators and APDs made read out with APDs difficult.

Studies of boron carbide (B4C) coated plastic scintillators and diodes were conducted as well. A neutron detection method using boron carbide coated diodes was tested. Proof of concept measurements were made using such coated diodes. The effect on the properties of plastic scintillators when coated with B4C were qualitatively assessed. (Less)
Please use this url to cite or link to this publication:
author
Söderström, Daniel LU
supervisor
organization
course
PHYM01 20161
year
type
H2 - Master's Degree (Two Years)
subject
keywords
neutron detection, neutron, 10B, boron-10, nuclear physics, boron, neutron detector, scintillator, boron carbide, B4C, nuclear fuel, repository, SKB
language
English
id
8882484
date added to LUP
2016-06-28 13:15:51
date last changed
2016-06-28 13:15:51
@misc{8882484,
  abstract     = {The nuclear reaction 10B(n,alpha)7Li* was utilised to develop a neutron detection system. This system has the purpose of being used to detect the thermal neutron radiation emitted by spent nuclear fuel, before it is transported to a final repository. This to investigate the content of the fuel-containing capsules, primarily to ensure non-proliferation of radioactive materials in the nuclear waste management process.

The investigated detector system utilises two scintillators mounted on one photomultiplier tube (PMT). One of them boron loaded to be sensitive to neutrons, and the other sensitive to gamma radiation to detect the de-excitation quanta released by the lithium ion, often left in an excited state after the 10B(n,alpha)7Li* reaction. The detection of these signals together reduces background noise, and those signals of interest are extracted from the others by a pulse shape discrimination scheme.

The possibility to read out the scintillator signals using an avalanche photodiode (APD) was also investigated. Inherent noise difficulties and poorly matched properties of scintillators and APDs made read out with APDs difficult.

Studies of boron carbide (B4C) coated plastic scintillators and diodes were conducted as well. A neutron detection method using boron carbide coated diodes was tested. Proof of concept measurements were made using such coated diodes. The effect on the properties of plastic scintillators when coated with B4C were qualitatively assessed.},
  author       = {Söderström, Daniel},
  keyword      = {neutron detection,neutron,10B,boron-10,nuclear physics,boron,neutron detector,scintillator,boron carbide,B4C,nuclear fuel,repository,SKB},
  language     = {eng},
  note         = {Student Paper},
  title        = {Development of a Detector System for Detection of Thermal Neutrons from Spent Nuclear Fuel},
  year         = {2016},
}