Electrostatic focusing of cold and heavy molecules for the ACME electron EDM search
Electrostatic focusing of cold and heavy molecules for the ACME electron EDM search
复制标题
用于 ACME 电子 EDM 搜索的冷分子和重分子静电聚焦
DOI：
10.1088/1367-2630/ac8014
复制
发表时间：
2022
影响因子：
3.3
通讯作者：
DeMille, D.
中科院分区：
文献类型：
--
作者：
Wu, X.;Hu, P.;Han, Z.;Ang, D. G.;Meisenhelder, C.;Gabrielse, G.;Doyle, J. M.;DeMille, D.
电子电偶极矩（EDM）的当前最佳上限，|D e| < 1.1× 10− 29 e cm（90%置信度），由ACME协作组在2018年设定。ACME实验使用一氧化钍（ThO）分子冷束中的自旋进动测量来检测d e。通过更有效地使用来自低温缓冲气体束源的分子，统计不确定性的改善将是可能的。在这里，我们演示了静电聚焦的ThO光束与六极透镜。这导致在下游可检测的分子通量中的16倍增强，在类似于为下一代ACME构建的光束线中。我们还展示了一个升级的旋转冷却方案，增加了3.5倍的基态人口相比，没有冷却，与预期和1.4倍，比以前在ACME大。当与其他表现出的改进相结合，我们的项目在统计灵敏度的下一代ACME电子EDM搜索的一个数量级的改善。
The current best upper limit for electron electric dipole moment (EDM),| d e|< 1.1× 10− 29 e cm (90% confidence), was set by the ACME Collaboration in 2018. The ACME experiment uses a spin-precession measurement in a cold beam of thorium monoxide (ThO) molecules to detect d e. An improvement in statistical uncertainty would be possible with more efficient use of molecules from the cryogenic buffer gas beam source. Here, we demonstrate electrostatic focusing of the ThO beam with a hexapole lens. This results in a factor of 16 enhancement in the molecular flux detectable downstream, in a beamline similar to that built for the next generation of ACME. We also demonstrate an upgraded rotational cooling scheme that increases the ground state population by 3.5 times compared to no cooling, consistent with expectations and a factor of 1.4 larger than previously in ACME. When combined with other demonstrated improvements, we project over an order of magnitude improvement in statistical sensitivity for the next generation ACME electron EDM search.