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

在过去的十年里，一系列实验展示了中微子领域最引人注目的发现之一：中微子有质量，它们会振荡。这是第一个令人信服的证据，证明了标准模型没有描述的现象，并且已经对天体物理学和宇宙学产生了重大影响。这也可能使我们进一步发现轻子部门的CP破坏，就像夸克部门存在CP破坏一样。这将是至关重要的，因为CP破坏是一种被认为是宇宙中物质和反物质不对称的起源的机制，但仅在夸克部分太小，不能解释所有的原因。只有当Muon中微子到电子中微子发生振荡时，才有可能访问中微子扇区的CP破坏。这项研究有两个关键目标：1.利用日本的T2K实验寻找从Muon中微子到电子中微子的振荡；2.领导开发基于T2K探测器技术的用于保障应用的反中微子监测器。T2K是一项长基线中微子实验，其主要目标是在振荡的Muon中微子束中寻找电子中微子的出现。Muon中微子束是在东海(日本东北部)的J-PARC设施中产生的，并在295公里外的神冈煤矿的大型水切伦科夫探测器Super-Kamiokande中探测到。这项研究的重点是在光束有时间振荡之前测量T2K近探测器上的中微子相互作用。这些测量将被用来描述超级神冈德的背景相互作用，以便最大限度地增加我们发现这种振荡的机会。T2K近探测器使用的技术已被发现非常适合在核反应堆监测中应用。反应堆堆芯是强大的中微子源，提供有关反应堆运行的准确信息。已确定使用高性能、实用和具有成本效益的中微子探测器非常适合今后执行国际原子能机构(原子能机构)的保障程序。这项研究将引领开发一种能够执行这项任务的设备，这将是中微子物理学的第一次实际应用。

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.