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.

精密磁力测量是下一代中子EDM测量的关键部分，灵敏度目标为10-28 ecm。在这个建议中，我们描述了一个独特的多室（共）磁强计设置读出的自旋旋进频率的极化199汞在磁场中的光学。它的主要特点是垂直堆叠的四个大容量磁力计单元和基于激光的读出和泵浦方案。该项目的主要目标是：（一）在nEDM测量运行期间提供在线磁场测量，每个磁强计单元的积分时间为250秒，所需灵敏度为< 10 fT;（二）提供关于主磁场垂直梯度的信息。在以前的实验中已经证明，使用汞放电灯可以实现一个磁力计单元40 fT的灵敏度。使用激光器作为光源，而不是将提供显着更高的泵浦功率和稳定性，这两个将大大提高信噪比，并允许我们提取的岁差频率的Hg与更高的精度。由于我们可以完全控制激光器的所有特性，因此我们也有独特的可能性来研究与读出光相关的系统效应。从所有四个单元获得的数据的组合使我们不仅可以获得平均磁场，还可以获得主磁场的可能的垂直梯度和扭曲。在这个项目中，我们希望开发一个系统，在三个阶段满足这两个目标。第一阶段是使用现有的单电池测试装置优化激光性能和汞电池特性。第2阶段包括在磁屏蔽环境中安装磁力计，并扩展到多个单元，以及对其他磁力测量系统进行测试，第3阶段是中子EDM实验和操作的最终实验设置的实施。