Entwicklung eines Mehrkammer-(Ko)Magnetometers mit 199Hg für eine neue Messung des Neutron EDM

开发 199Hg 多室（共）磁力计，用于中子 EDM 的新测量

• 批准号: 237445972
• 负责人: Dr. Gerd Petzoldt
• 金额: --
• 依托单位: Exzellenzcluster Universe (aufgelöst)
• 依托单位国家: 德国
• 项目类别: Priority Programmes
• 财政年份: 2013
• 资助国家: 德国
• 起止时间: 2012-12-31 至 2017-12-31
• 项目状态: 已结题
• 来源: https://gepris.dfg.de/gepris/projekt/237445972?language=en
• 关键词: Entwicklung; eines; Mehrkammer; Ko; Magnetometers

Precision magnetometry is a crucial part for a next-generation measurement of the neutron EDM with a sensitivity goal of 10-28 ecm. In this proposal, we describe a unique multi-chamber (co-)magnetometer setup which reads out the spin precession frequency of polarized 199Hg in a magnetic field optically. Its main features are a vertical stack of four large-volume magnetometer cells and a laser-based read-out and pumping scheme. The main goals of the project are to provide (i) online magnetic field measurements in-situ during nEDM measurement runs with the required sensitivity of < 10 fT for 250 s integration time per magnetometer cell and (ii) information about vertical gradients of the main magnetic field. It has been demonstrated in previous experiments that a sensitivity of 40 fT for one magnetometer cell is achievable using Hg discharge lamps. Using a laser as lightsource instead will provide significantly higher pumping power and stability, both of which will greatly increase the signal-to-noise ratio and allow us to extract the precession frequency of the Hg with higher precision. Since we have full control over all of the laser's properties, we also have unique possibilities to study systematic effects connected to the read-out light. The combination of data obtained from all four cells gives us access to not only the mean magnetic field but also to possible vertical gradients and distortions of the main magnetic field. Within this project we want to develop a system that meets both goals in three stages. Stage 1 is the optimization of laser performance and Hg cell properties using an existing test setup with one cell. Stage 2 consists of the installation of the magnetometer in a magnetically shielded environment and the expansion to multiple cells, as well as testing against other magnetometry systems and stage 3 is the implementation into the final experimental setup of the neutron EDM experiment and operation.

精度磁力测定法是对中子EDM进行下一代测量的关键部分，其灵敏度目标为10-28 ECM。在此提案中，我们描述了一种独特的多室（共同）磁力计设置，该设置在光学上读出了磁场中极化199hg的自旋进动频率。它的主要特征是由四个大容量磁力计电池组成的垂直堆栈和一个基于激光的读出和抽水方案。该项目的主要目标是在NEDM测量过程中提供（i）在线磁场测量值，其所需的灵敏度为每个磁力计单元的250 s集成时间，以及（ii）有关主磁场垂直梯度的信息。在先前的实验中已经证明，使用HG排放灯可以实现40英尺对一个磁力计细胞的灵敏度。相反，使用激光作为Lightsource将提供更高的泵浦功率和稳定性，这两者都将大大提高信噪比，并使我们能够以更高的精度提取HG的进动频率。由于我们对所有激光器的属性都有完全控制，因此我们也有独特的可能性研究与读出光相连的系统效应。从所有四个细胞中获得的数据的组合不仅使我们进入平均磁场，还可以进入可能的垂直梯度和主磁场的扭曲。在这个项目中，我们希望开发一个在三个阶段符合两个目标的系统。阶段1是使用一个单元格的现有测试设置对激光性能和HG单元性能的优化。第2阶段包括在磁性屏蔽环境中安装磁力计以及对多个单元的扩展以及针对其他磁力测定系统的测试和第3阶段的测试是对中子EDM实验和操作的最终实验设置的实现。