Fundamental measurements with cold neutrons: Nab and BL3 experiments

该项目包括美国橡树岭国家实验室的Nab实验和美国国家标准与技术研究所的BL3实验。Nab将对某些中子衰变参数进行最精确的测量，BL3实验将对中子束进行最精确的中子寿命测量。这两个实验将共同阐明当今领先的粒子物理理论，并帮助我们找到一个真正描述我们生活的世界的理论。Nab目前处于调试阶段，将从2022年到2025年收集物理数据。加拿大Nab小组负责测试实验中使用的新型大面积Si探测器，我们在曼尼托巴大学为此目的建造了一个可操纵的30 keV质子加速器。该小组已经测试了一组带有30个keV质子的Nab Si探测器，将建立一个新的探测器底座，并测试另一系列探测器，以研究各种探测器的系统效应，从而使Nab实验能够达到其误差预算目标。此外，该组成员将参与物理数据采集数据分析。加拿大BL3小组负责测试BL3实验使用的Si探测器，它与Nab实验使用的Si探测器非常相似。一种被称为质子后向散射的系统效应，即质子从Si探测器表面散射出去，将作为质子能量和后向散射角的函数进行研究。这项研究将为确保BL3达到其系统误差目标提供关键信息。本项目每年暑期招收博士后1人、研究生2人、本科生1人（共3个暑期）。这些人员将：在曼尼托巴大学建立Nab Si探测器表征座并使用30 keV质子束进行测试。开发硬件并在马尼托巴大学的30 keV质子束线探测器测试室中实现背散射探测器。通过在ORNL执行数据轮班和物理数据分析，与更大的Nab协作接口。在国内和国际会议上介绍他们在30 keV质子束、Nab Si探测器测试和质子在Si表面后向散射方面的工作，并在适当的参考科学期刊上发表结果。通过这些活动，HQP将获得计算机辅助设计和建模、简单加工、真空硬件、电子信号处理和数据采集技术、先进计算和数据分析实践以及演示和写作方法等方面的宝贵技能和经验。此外，博士后和研究生将在与本科生共同完成项目的过程中获得宝贵的指导经验。这些技能将使他们为各种职业做好准备，特别是在加拿大的STEM领域。

This project encompasses the Nab experiment, at Oak Ridge National Lab and the BL3 experiment at the National Institute of Standards and Technoloy, both in the USA. Nab will make the most precise measurements of certain neutron decay parameters and the BL3 experiment will make the most precision neutron lifetime measured with a beam of neutrons. Together both experiments will shed light on the leading particle physics theories of today and help us home in on a theory that truly describes the world we live in. Nab is currently in its commissioning phase and will collect physics data from 2022-2025. The Canadian Nab group is responsible for testing the novel large area Si detectors used in the experiment where we have built a steerable 30 keV proton accelerator at the University of Manitoba for this purpose. The group has tested a set of Nab Si detectors with 30 keV protons will build a new detector mount and test another series of detectors to investigate various detector systematic effects so the Nab experiment can reach it error budget goals. In addition, the members of this group will participate in physics data taking data analysis. The Canadian BL3 group is responsible for testing the Si detectors used by the BL3 experiment, which are very similar to the Si detectors used by the Nab experiment. A systematic effect known as proton backscattering, where protons scatter off the surface of the Si detector surface will be studied as a function of proton energy and backscattering angle. This study will provide crucial information to ensure the BL3 meets its systematic error goals. The HQP in this project include one postdoc, two graduate students, and 1 undergraduate student each summer (for 3 summers). These personnel will: Build the Nab Si detector Characterization Mount and test with the 30 keV proton beam at the University of Manitoba. Develop the hardware and implement a backscatter detector into the 30 keV proton beam line detector test chamber at the University of Manitoba. Interface with the larger Nab collaboration, by performing data taking shifts and physics data analysis at ORNL. Present their work related to the 30 keV proton beam, the Nab Si detector tests, and the proton backscattering off Si surfaces at national and international conference and publish the results in the appropriate referred scientific journals. Through these activities the HQP will gain valuable skills and experience in computer aided design and modeling, simple machining, vacuum hardware, electronics signal processing and data acquisition techniques, advanced computing and data analysis practices, and presentation and writing methods. In addition, the postdoc and graduate students will get valuable mentoring experience while they work together with the undergraduate students to complete the projects. These skills will prepare them for a variety of careers, especially those in Canada's STEM fields.