Phd Opportunities

November 2016

WATCHMAN: an anti-neutrino detector for nuclear non-proliferation studies

The WATCHMAN project involves a joint US-UK collaboration of universities and national labs who are working to design and build an anti-neutrino detector deep underground that will monitor anti-neutrinos from nearby nuclear reactors. The ultimate goal of the project is to develop a tool that can be used in nuclear non-proliferation applications. This PhD will involve both computational and experimental work. The former will involve simulations of the sensitivity of the proposed detector and the assessment of the effect of backgrounds (e.g. cosmic-induced or natural radioactivity) to the performance of the detector. The expected time scale for the construction of WATCHMAN and the start of data-taking falls within the duration of this PhD (approximately 2019). Therefore, the experimental work will involve building, calibrating, and running the detector, as well as an analysis of the first reactor anti-neutrino data.

Contact: Prof Lee Thompson (l.thompson@sheffield.ac.uk) and Dr Matthew Malek (m.malek@sheffield.ac.uk)

Detector development for homeland security applications

The group has a long-standing track record of attracting grant income for applications of particle physics instrumentation in various areas. This studentship will be involved in consolidating existing work on developing methods and materials to augment and improve current techniques used in the border and mainland security. The PhD position will be largely experimental but some will involve some data analysis. There is the possibility of industrial placements during the period of study.

Contact: Prof Lee Thompson (l.thompson@sheffield.ac.uk)

Detection of Contraband Explosives Using Neutron Activation

The Sheffield Pulsed Neutron Facility has been set up to assess cargo screening strategies based on neutron activation and induced fission. It is based on an inertial electrostatic confinement generator using deuterium-tritium fusion to produce pulses of 14MeV neutrons. This generator was manufactured by NSD-Fusion, now NSD-Gradel, Luxembourg. To date, the generator has been proven to operate reliably and many of its characteristics have been measured. Some of the possible cargo screening strategies have been demonstrated to work with simple single detector setups. In particular the thermal activation of nitrogen as an indicator of the presence of nitrogenous explosives is detectable with kilogram surrogate samples. We would like to extend this work by engineering an array of detectors capable of simultaneous measurement of gamma rays over a wide range of energies up to 12MeV. Additionally fast and thermal neutrons should be measured to assess neutron transparency and thermalization properties of sample cargoes. These detectors will be read out by a data acquisition system recording the energies and time-stamping hits over a time scale considerably longer than the thermalization time of the system. It is intended that the fusion of these data streams will allow considerably more exact characterization of potential threats than a single measurement would permit. Explosives will be identifiable by CHNO ratios, while fissile nuclear materials will be identifiable by die-away analysis which will distinguish delayed fissions.

Contact: Dr John McMillan (j.e.mcmillan@sheffield.ac.uk)