Speaker
Description
For the upcoming Lithium Breeding Tritium Innovation (LIBRTI) facility at UKAEA, a D-T neutron generator will be utilised. This source will be surrounded by breeder blanket material to produce tritium, where one of the aims is to determine the tritium breeding ratio (TBR). Monitoring the neutron flux and neutron energies provided by the source is essential for measuring the tritium consumed. To prepare for the operation of the LIBRTI facility in the coming years, a neutron diagnostics system capable of measuring the both the neutron flux and neutron energies emitted by the D-T generator is currently being designed. In this presentation, the proposed design is discussed.
The D-T source is cooled using water, which is then transported outside the target through pipework. By measuring the activation products within the source cooling water, a measurement of neutron flux can be achieved that is not impeded by the presence of the breeder blanket. The proposed method is to measure gamma rays following the beta decay of 16N and beta-delayed neutron emission from 17N using scintillators. By selecting a scintillator with strong pulse shape discrimination (PSD) capabilities for the desired energies, signals from gamma rays and neutrons can be separated, with both signals providing a value of neutron flux. This is the first use of PSD for this application in the fusion sector. Furthermore, traditional neutron monitoring techniques such as the use of fission chambers and activation foils around the source will be utilised and discussed.