A search for the last neutrino flavour mixing angle with the T2K experiment and development of novel detector technique for safeguards application

In the last ten years a combination of experiments has demonstrated one of the most striking discoveries in the neutrino sector: neutrinos have mass and they oscillate. This is the first compelling evidence for a phenomena that is not described by the standard model and which has already had great consequences for astrophysics and cosmology. It might also bring us further to the discovery of CP violation in the lepton sector in a similar way that CP violation is present in the quark sector. This will be of utmost importance as CP violation is a mechanism believed to be at the origin of matter and anti-matter asymmetry in the universe but too small in the quark sector alone to explain all of it. Accessing CP violation in the neutrino sector is only possible if oscillation of muon neutrino to electron neutrino takes place. This research has two key objectives: 1. to search for the oscillations of muon neutrino to electron neutrino using the T2K experiment in Japan; and 2. to lead the development of an anti-neutrino monitor for safeguards applications based on T2K detector techniques. T2K is a long baseline neutrino experiment, whose main goal is to look for appearance of electron neutrinos in an oscillated beam of muon neutrinos. The muon neutrino beam is created at the J-PARC facility in Tokai (north-east Japan) and detected 295 km away in the large water Cherenkov detector Super-Kamiokande in the Kamioka mine. This research focuses on measurement of neutrino interactions at the T2K near detector before the beam has had time to oscillate. These measurement will be used to characterise background interactions at Super-Kamiokande in order to maximise our chance of discovering this oscillation. Technology based used at the T2K near detector has been found to be well suited for application in nuclear reactor monitoring. Reactor cores are powerful neutrino sources and give precise information about the reactor operation. The use of high performance, practical and cost-effective neutrino detector has been identified as being well suited for future implementation of the International Atomic Energy Agency (IAEA) safeguard procedures. This research would lead the way in the development of a device capable of performing this task which would be the first practical application of neutrino physics.