Dark Matter Direct Detection in the DarkSide-20k Experiment

暗物质的性质是当今宇宙的基本问题之一，处于物理学研究的前沿。直接探测实验旨在观察暗物质粒子与原子核的相互作用。Darkside-20K是一项国际合作计划，旨在开发用于低本底搜索的下一代液体氩(LAR)探测器。50吨重的Darkside-20K探测器正在意大利Gran Sasso的LNGS实验室建设中，计划于2023年开始第一次运行。Darkside-20K将比目前搜索质量在TeV级的暗物质粒子的灵敏度增加两个数量级。这个学生项目是致力于开发主动否决权探测器光传感器、电子学、数据采集系统和模拟。随着寻找暗物质的实验变得更加灵敏，背景需要以前所未有的水平被理解。为此，正在开发世界领先的光电传感器技术和读数，以便能够识别信号和背景事件，同时还能最大限度地减少它们自身的放射性足迹，这是将暗物质搜索的背景事件降至最低的关键要求。该项目将描述和校准光电传感器硬件，帮助建造和调试否决权探测器，并开发分析数据的分析工具。其目标是开发一种具有灵活性的暗物质搜索分析，以搜索包括超出WIMP暗物质假说的奇异暗物质候选的信号。

The nature of dark matter is one of the fundamental questions about the universe today, at the forefront of physics research. Direct detection experiments seek to observe interactions of dark matter particles with atomic nuclei. DarkSide-20k is an international collaboration engaged in a staged program to develop the next generation of liquid argon (LAr) detectors for low-background searches. The 50 tonne DarkSide-20k detector is under construction in the LNGS laboratory, in Gran Sasso, Italy, first operations planned begin in 2023. DarkSide-20k will have two orders of magnitude increase in the sensitivity over current searches for dark matter particles with masses at the TeV scale.This studentship project is to work on development of the active veto detector photosensors, electronics, data acquisition system and simulation. As experiments become more sensitive in search of dark matter, backgrounds need to be understood at levels never before achieved. To do so, world-leading photosensor technology and readout are being developed that will allow the identification of signal and background events whilst also minimising their own radioactive footprint, a key requirement to minimise background events to the dark matter search.This project will characterise and calibrate the photosensor hardware, contribute to building and commissioning the veto detector and develop analysis tools to analyse data. The goal is to develop a dark matter search analysis with flexibility to search for signals including exotic dark matter candidates beyond the WIMP dark matter hypothesis.