Ultracold neutrons at TRIUMF: bridging grant for new member

TRIUMF 超冷中子：为新成员提供过渡补助金

• 批准号: SAPPJ-2017-00045
• 负责人: Franke, Beatrice
• 金额: $ 2.91万
• 依托单位: TRIUMF
• 依托单位国家: 加拿大
• 项目类别: Subatomic Physics Envelope - Project
• 财政年份: 2018
• 资助国家: 加拿大
• 起止时间: 2018-01-01 至 2019-12-31
• 项目状态: 已结题
• 来源: https://www.nserc-crsng.gc.ca/ase-oro/Details-Detailles_eng.asp?id=651075
• 关键词: Ultracold; neutrons; TRIUMF; bridging; grant

The matter-antimatter asymmetry in the universe is one of the biggest questions in fundamental physics, as well as philosophy. The neutron electric dipole moment (nEDM) is related to this asymmetry and can thus help shed light on this unsolved puzzle. Experiments searching for the nEDM have also ruled out several particle physics theories over the last five decades. So far, the most stringent limits on the nEDM have been set by experiments using ultracold neutrons; these are so slow that they are reflected by certain wall materials and can subsequently be stored and observed for hundreds of seconds.***TRIUMF's Ultracold Neutron program aims at providing the world's highest intensity of ultracold neutrons (UCN) to experiments. Furthermore, the Canadian-Japanese collaboration behind the TRIUMF UCN project wants to achieve a world leading ultimate sensitivity of 10−27 ecm to the nEDM. This search constitutes the flagship experiment of UCN physics.******The research program suggested in this proposal extends over two years and is intended as bridging grant for a new collaboration member. The rest of the UCN collaboration is supported by NSERC grant SAPPJ-2016-00024. The co-applicant is the principal applicant of this existing grant and is signing this application for administrative purposes only.***The main goal of this research proposal is the successful integration of the nEDM apparatus into the TRIUMF UCN facility. Two milestones are (i) filling and storing UCN into the existing Phase 1 nEDM apparatus, and (ii) the observation of Larmor precession of the stored UCN. This is very challenging due to the harsh environmental conditions in the direct proximity of the cyclotron accelerator which include (among others) high magnetic background fields, as well as time varying magnetic fields caused by other close-by experiments and infrastructure such as cranes and loading doors. The stability and homogeneity of the magnetic field, however, are crucial ingredients to the feasibility of Larmor precession experiments, and subsequently to the sensitivity of an nEDM measurement.***The applicant has gathered ample expertise in magnetic field observation and manipulation, as well as with nEDM measurements during her PhD studies and additionally is very experienced with UCN experiments by participating in UCN measurement campaigns at the institutes FRM-II in Germany, ILL in France, and PSI in Switzerland through her entire scientific career. This will be essential to the success of the UCN source and EDM experiment at TRIUMF.**

宇宙中的物质距离不对称是基本物理和哲学中最大的问题之一。中子电偶极矩（NEDM）与这种不对称性有关，因此可以帮助阐明这个未解决的难题。在过去的五十年中，搜索NEDM的实验也排除了几种粒子物理理论。到目前为止，NEDM上最严格的限制是通过使用超低中子实验设定的。它们是如此慢，以至于它们被某些壁材料反射，随后可以存储并观察到数百秒钟。此外，《 Triumf UCN项目》背后的加拿大日本合作希望以10-27 ECM对NEDM的最终敏感性达到世界。这项搜索构成了UCN物理学的旗舰实验。 NSERC GRANT SAPPJ-2016-00024支持其余的UCN合作。共同实施是该现有赠款的主要应用，仅出于行政目的签署了此申请。两个里程碑是（i）将UCN填充并存储到现有的1阶段NEDM设备中，以及（ii）观察到Larmor预防存储的UCN。由于环境加速器直接接近的有害环境条件，包括（除其他）高磁性背景场以及其他近距离实验和基础设施（例如起重机和装载门）引起的时间变化，这是非常挑战的。然而，磁场的稳定性和同质性对于Larmor预防实验的可行性以及随后对NEDM测量的敏感性至关重要。在她的整个科学生涯中，该机构在德国，法国生病的FRM-​​II和瑞士的PSI。这对于Triumf的UCN源和EDM实验的成功至关重要。**