Nuclear non-proliferation via hardware and software work on the WATCHMAN detector

水切伦科夫反中微子监测器(Watchman)是美国和英国的合作项目，旨在利用自然界最“幽灵”的粒子(中微子)来降低核威胁的极端实用目的。Watchman将使用新兴的Gd加载技术来增强已有数十年历史的水切伦科夫中微子探测器技术。在所有元素中，Gd具有最高的中子俘获截面。当反中微子通过逆β衰变在探测器中相互作用时，产生的正电子和捕获剩余中子的符合提供了一个明确的信号。这种新的Gd标记技术将被用于其他物理测量的实验中。在Watchman中，首要目标是减少核威胁--实现对核反应堆动力和核不扩散的远程监测。虽然核武器试验的辐射可以屏蔽，但反中微子是无法屏蔽的。因此，守望者类型可以成为21世纪防扩散的重要工具。谢菲尔德守望者小组正在与博尔比地下实验室和原子武器机构合作，在博尔比实验室设计和建造守望者原型。建设阶段于2018年10月开始，我们团队几乎参与了实验的所有领域，包括电子、校准、光电倍增管、模拟和数据分析。博士生也有机会参与Watchman未来阶段的研发，例如新的快速光电传感器和新的探测器目标。这项研发将旨在增强Watchman的防扩散能力，同时也使探测器有可能研究粒子和天体粒子物理主题，如超新星中微子、CNO太阳中微子、地球中微子和无中微子双β衰变。

The WATer CHerenkov Monitor for Anti-Neutrinos (WATCHMAN) is a US/UK collaboration that aims to use nature's most 'ghostly' particle (the neutrino) for the extremely practical purpose of nuclear threat reduction. WATCHMAN will enhance the decades-old technology of water Cherenkov neutrino detectors with the emerging technique of gadolinium loading. Gadolinium has the highest cross-section for neutron capture of all the elements. When an anti-neutrino interacts in the detector via inverse beta decay, the coincidence of the produced positron and the capture of the leftover neutron provides an unambiguous signal.This new gadolinium-tagging technique will be employed in other experiments for physics measurements. In WATCHMAN, the primary goal is nuclear threat reduction -- achieving a long-distance monitoring of nuclear reactor power and non-proliferation. Although the radiation from a nuclear weapons test can be shielded, the anti-neutrinos cannot be masked. Thus, a WATCHMAN-type can be an important tool for non-proliferation in the twenty-first century.The Sheffield WATCHMAN group is working with the Boulby Underground Laboratory and the Atomic Weapons Establishment to design and construct a WATCHMAN prototype at the Boulby Lab. The construction phase began in October 2018, and our group is involved in nearly all areas of the experiment, including electronics, calibration, photomultiplier tubes, simulations, and data analysis. There is also the opportunity for a PhD student to get involved with R&D for future phases of WATCHMAN, such as new fast photosensors and novel detector targets. This R&D will aim to enhance the non-proliferation power of WATCHMAN whilst also opening up the detector to the possibility of studying particle and astroparticle physics topics, such as supernova neutrinos, CNO solar neutrinos, geoneutrinos, and neutrinoless double beta decay.