Infrastructure Request for High Pressure Gas TPC Development Studies for the DUNE Near Detector

宇宙中的反物质是如此微不足道，以至于我们的世界存在的时间足以让智慧生命进化。但我们的知识却不是这样说的：按理说，所有的物质和反物质都应该等量地被湮灭。解开这个谜题的唯一钥匙来自中微子和反物质中微子之间的行为差异，这可以通过基于加速器的中微子实验来研究。有了更强大的加速器和更精密的探测器，我们正在以前所未有的精度检测中微子的相互作用。深地下中微子实验（DUNE）是美国的下一代中微子实验，旨在寻找中微子和反中微子之间的微小不对称性，并寻找源自粒子物理标准模型之外的罕见事件。DUNE将通过测量中微子振荡来做到这一点，中微子振荡是一种现象，中微子在从费米实验室产生到被1200公里外的远端探测器（FD）探测的过程中改变类型。DUNE- uk项目是DUNE在美国之外做出的最大贡献，将对实验的建设做出重大贡献。目前主要致力于DUNE数据采集（DAQ）、FD和波束线的建设。FD模块计划从2027年开始上线，随后是2030年的光束，2032年的近距离探测器（ND）。ND复合体包括一个液态氩TPC，一个高压气体时间投影室（HPgTPC），由一个螺线管和一个量热计封闭，以及一个轴向光束监视器。这个复合物的设计目的是精确地表征中微子束，并以前所未有的细节研究中微子-核相互作用，以便更好地理解导致振荡测量的各自系统误差。目前正在设计的DUNE ND的HPgTPC将成为研究中微子相互作用的终极探测器，因为它具有非常低的探测阈值，完全的角度接受，以及非常大的高压气体体积提供了大的目标质量。近期，概念设计报告已经发布，技术设计报告（TDR）正在编制中。美国的合作者在HPgTPC的磁体和机械设计方面处于领先地位，而英国的机构则参与了气体研究、读出技术开发、电子和DAQ设计以及读出室的波束测试。我们建议在华威大学建立HPgTPC研发平台。它由三种原型设备组成：1。HPgTPC, 2。2 .高性能光学读出系统；激光放射性气体校准系统。虽然我们通过前两款设备巩固了我们在气体研究和读出技术开发领域的领导地位，但拟议的激光校准系统旨在为HPgTPC气体质量控制提供技术解决方案，这被认为是TDR的重中之重。本提案中的平台将为英国加速器-中微子气体TPC研发提供唯一的本地支持。该提案的资本资助将非常及时地推动英国对HPgTPC概念的进一步研发，并将很好地补充英国对DUNE近探测项目的贡献。

Antimatter in the universe is so negligible that our world exists long enough for intelligent life to evolve. But our knowledge says otherwise: By the book, all matter should have obliterated together with antimatter in equal parts. The only key to unlocking this puzzle comes from the behavioural difference between neutrinos and anti(matter-)neutrinos, which can be studied by accelerator-based neutrino experiments. With more powerful accelerators and sophisticated detectors, we are on the way to examining neutrino interactions with unprecedented precision. The Deep Underground Neutrino Experiment (DUNE) is the next-generation neutrino experiment in the US designed to look for the tiny asymmetry between neutrinos and antineutrinos and search rare events that originate from physics beyond the Standard Model of particle physics. DUNE will do this by measuring neutrino oscillations, a phenomenon where neutrinos change type on their way from their production at Fermilab to their detection by the Far Detector (FD) 1200 km away. The DUNE-UK project is the biggest DUNE contribution outside the US and will contribute significantly to the construction of the experiment. It currently focuses on the construction of the DUNE data acquisition (DAQ), FD, and the beamline. The FD modules are planned to be online from 2027, followed by the beams in 2030, and the near detector (ND) in 2032. The ND complex consists of a liquid argon TPC, a High Pressure gas Time Projection Chamber (HPgTPC) enclosed by a solenoid and a calorimeter, and an on-axis beam monitor. This complex is being designed to precisely characterise the neutrino beams and to study neutrino-nucleus interactions with unprecedented details so that the respective systematic errors contributing to the oscillation measurements are much better understood. The HPgTPC of the DUNE ND, currently being designed, will be the ultimate detector to study neutrino interactions due to its very low detection threshold, full angular acceptance, and very large high-pressure gas volume providing a large target mass. Recently, the Conceptual Design Report has been published, and the Technical Design Report (TDR) is currently being prepared. While the US collaborators are leading the R&D in the magnet and mechanical designs of the HPgTPC, UK institutions are involved in gas studies, readout technology development, design of electronics and DAQ, and in a beam test of the readout chambers. We propose to build an HPgTPC R&D Platform at the University of Warwick. It consists of three items of prototype equipment:1. a HPgTPC,2. a high-performance optical readout system, and3. a laser-radioactive gas-calibration system.While we are consolidating our leadership in the field of gas studies and readout technology development with the first two pieces of equipment, the proposed laser calibration system aims to provide a technical solution to the HPgTPC gas quality control that is considered a high priority for the TDR. The Platform in this proposal will provide the only local support for accelerator-neutrino gas TPC R&D in the UK. Capital funding for this proposal would represent a very timely push for further R&D into the HPgTPC concept in the UK and would complement well efforts to extend UK contributions to the DUNE Near Detector project.