Magnetometry at the fTesla-scale for neutron EDM experiments using a co-habiting Xenon magnetometer based on free spin precession

新的中子EDM实验，如保罗·谢勒研究所（PSI）的国际中子EDM合作，旨在达到10-28 ecm的测量灵敏度，与目前中子电偶极矩（nEDM）的上限dn < 3 x 10-26 ecm相比，有两个数量级的改进。为了实现这一雄心勃勃的目标，需要在200 s的典型Ramsey循环期间达到1 fT灵敏度水平的磁力测量。在这个建议中，我们专注于发展的氙磁强计，它应该能够监测和纠正几何相位引起的假nEDM效果。这些假效应设定了dn的当前系统极限，假的10 μ m-26 μ cm，由众所周知的vxE场与磁场梯度的相互作用引起，并产生与模拟nEDM的电场线性的频移。这种频移可以使用分离振荡场的拉姆齐方法来测量。自旋极化氙通过光泵产生，核自旋的自由进动（共存原子氙磁力计）在nEDM光谱仪的超冷中子（UCN）存储体积内进行监测。

Novel neutron EDM experiments, like the international neutron EDM collaboration at the Paul Scherrer Institute (PSI) aim to reach a measurement sensitivity of ≈ 10-28 ecm, a two orders of magnitude improvement compared to the present upper limit of dn < 3 x 10-26 e∙cm for the neutron electric dipole moment (nEDM). In order to reach this ambitious goal, magnetometry reaching the 1 fT sensitivity level during a typical Ramsey cycle of 200s is demanded. In this proposal we concentrate on the development of a Xenon magnetometer which should be able to monitor and correct geometric phase induced false nEDM effects. These false effects, which set the present systematic limit of dn, false ≈ 10-26ecm, result from the interaction of the well known vxE-field with magnetic field gradients and produce a frequency shift linear to the electric field mimicking an nEDM. This frequency shift can be measured using the Ramsey method of separated oscillatory fields. Spin-polarized Xenon is produced by optical pumping and the free precession of nuclear spins (co-habiting atomic Xenon magnetometer) is monitored within the ultracold neutron (UCN) storage volume of the nEDM spectrometer.