Measurement of the neutron lifetime using magnetically trapped neutrons: tSPECT

使用磁俘获中子测量中子寿命：tSPECT

• 批准号: 319989837
• 负责人: Professor Dr. Werner Heil
• 金额: --
• 依托单位: Institut für Physik
• 依托单位国家: 德国
• 项目类别: Research Grants
• 财政年份: 2016
• 资助国家: 德国
• 起止时间: 2015-12-31 至 2020-12-31
• 项目状态: 已结题
• 来源: https://gepris.dfg.de/gepris/projekt/319989837?language=en
• 关键词: Measurement; neutron; lifetime; using; magnetically

The lifetime of the free neutron is a basic physical quantity, which is relevant in a variety of different fields of particle and astrophysics. In this project a precise measurement of the neutron lifetime using three-dimensional magnetic storage of ultra-cold neutrons (UCN) will be conducted. The differences in the results of experiments using different methods, beam and material bottle experiments, indicate that there are still some subtle and not understood effects in some of these experiments. Rather than relying on neutron reflection from a material wall, where neutron up-scattering and capture cause significant wall losses, magnetically trapped neutrons do not interact with matter during storage. That is the obvious appeal to the use of magnetic and gravitational confinement, where, at least in principle, the dynamics of the neutron-trap interaction is well understood and under control. The experiment tSPECT is located at the pulsed UCN-source of the TRIGA Mainz research reactor. It will become fully operational end of 2016. In the requested 3 years funding period beam times will be conducted to study and to minimize the systematic effects. A measurement of a competitive neutron lifetime with ~ 1 s accuracy is planned towards the end of the funding period (during the last third). We aim to continue tSPECT in an upgraded version in the framework of PRISMA II, the planned continuation of the excellence cluster PRISMA. An overall accuracy of delta tn = 0.2-0.3 s is envisaged.

自由中子的寿命是一个基本的物理量，它与粒子物理和天体物理的许多不同领域有关。本项目将利用超冷中子的三维磁存储（UCN）进行中子寿命的精确测量。使用不同方法的实验结果的差异，束和材料瓶实验，表明在这些实验中的一些仍然有一些微妙的和不理解的影响。而不是依赖于来自材料壁的中子反射，其中中子向上散射和捕获导致显著的壁损失，磁捕获的中子在存储期间不与物质相互作用。这就是使用磁约束和引力约束的明显吸引力，至少在原则上，中子-陷阱相互作用的动力学是很好理解和控制的。实验tSPECT位于TRIGA美因茨研究反应堆的脉冲UCN源。它将于2016年底全面投入使用。在要求的3年资助期内，将进行光束时间研究，并将系统影响降至最低。计划在供资期结束时（在最后三分之一期间）测量具有竞争力的中子寿命，精度约为1秒。我们的目标是在PRISMA II的框架内继续tSPECT的升级版本，PRISMA II是计划中的PRISMA卓越集群的延续。预计总精度为Δ tn = 0.2-0.3 s。