Improving the understanding of Gadolinium for use in Neutron Detectors

This project will primarily be based at: The University of Liverpool

Summary

Neutron detectors that employ Gadolinium (Gd) as the neutron capture agent can be enhanced by improving the understanding of the subsequent gamma cascade of the neutron capture on Gd. This would open up a new area of development where the neutron has the potential to be (partially) tagged, resulting in better background discrimination. This is particularly useful in large area detectors where intrinsic radiation in the scintillator or the photo-sensor itself is a large source of background, enabling new deployment scenarios.

Gd has an extremely large thermal neutron capture cross-section, second only to the capture cross-section of Xenon. The neutron capture on Gd has a Q-value of 8-MeV resulting in an associated gamma-ray cascade.

Gd(n, gamma) interactions have been studied and the integrated spectrum is known, but the individual decay modes have not been measured. The 4-gamma mode is dominant, although these are not measured to be discrete energies and it is not known if the energy of the four gammas is equal to the Q-value of the decay (8 MeV). Given the available energy there is likely to be multiple sub-MeV cascades. The PhD will calculate and measure the gamma spectrum, hence determining what is missing in each detected event and allowing the events to be tagged.

The PhD candidate will: first make the relevant calculations (currently unavailable in the literature); then take the relevant measurements; subsequently the experimental data will be compared against these calculations. 

About GREEN

The GREEN Centre for Doctoral Training (GREEN CDT) is a a consortium of five universities: The University of Manchester, Lancaster University, The University of Leeds, The University of Liverpool and The University of Sheffield, which aims to train the next generation of expert nuclear scientists and engineers.

Students within the GREEN CDT are invited to undertake a four-year PhD programme. Students will attend taught courses (Year 1) in various subject of nuclear technology followed by subject specific training (Year 1) leading to research activities (Year 2-Year 4).