Level 1 trigger developments for the upgrade of the CMS detector for the High Luminosity LHC [HL-LHC]

欧洲核子研究中心的大型强子对撞机（LHC）在可预见的未来将是世界上能量最高的粒子加速器，也是唯一能够研究基础物理学中一些最优先主题的设施。大型强子对撞机的运行将至少持续到2035年，为了提供有用的统计范围和相关的探测器，对加速器复合体的性能要求不断提高。因此，CMS检测器将需要进行重大和全面的升级，以便在更恶劣的条件下保持性能。联合王国在跟踪系统、端盖热量计和触发系统升级的关键方面发挥着主导作用。共同的要素是高通量数字电子的发展，以及它们对上述三个特定子系统的定制。克里斯的博士学位专注于1级触发系统的开发。触发器是潜在感兴趣的事件的真实的时间选择，并且对于将数据采集率降低到可管理的水平至关重要。严酷的HL-LHC条件将首次要求在该过程的最早阶段使用跟踪信息。Chris将研究实际的轨迹查找，重点关注机器学习技术来去除假轨迹，以及优化跟踪信息的使用以形成顶点和更复杂的对象。他将需要开发这些过程的软件仿真，然后在固件中实现算法，并在实际测试台上验证结果。

The Large Hadron Collider (LHC) at CERN will be the world's highest energy particle accelerator for the foreseeable future, and the only facility capable of investigating some of the highest priority topics in fundamental physics. LHC operation will continue until at least 2035, with ever-increasing performance required from the accelerator complex in order to provide useful statistical reach and from the associated detectors. As such the CMS detector will require significant and comprehensive upgrades in order to maintain performance in the presence of much harsher conditions. The UK is leading key aspects of the upgrades to the tracking system, end-cap calorimeters and the trigger system. The common element is the development of high throughput digital electronics, and their tailoring to the three specific sub-systems mentioned above. Chris's PhD is focused on developments for the Level 1 trigger system. The trigger is the real time selection of events of potential interest and critical in reducing the data-taking rate to a manageable level. The harsh HL-LHC conditions will require, for the first time, the use of tracking information at the earliest stages of the process. Chris will look at both the actual track finding, focusing on machine learning techniques to remove fake tracks, as well as optimising the use of the tracking information to form vertices and more complex objects. He will need to develop software emulation of these processes before then implementing the algorithms in firmware, as well as validating results with actual test stands.