3He Spin Transport Magnet Development for the SNS nEDM Experiment

Measurements of the neutron electric dipole moment (nEDM) are one of the most important tests of the parity and time reversal symmetries with implications both to baryogenesis in the early universe and fundamental physics. The SNS nEDM experiment aims to make a measurement to an accuracy of $3\times10^{-28}$ e-cm, 100 times better than previously existing measurements that have set an upper limit on the value of the nEDM. One of the methods to be used to meet the goal accuracy will be to use polarized helium-3 both as a co-magnetometer and as part of the neutron polarization measurement process.


A novel series of magnets are planned to be used to transfer the polarized helium-3 from the atomic beam source into the nEDM measurement cell. As part of the magnet development process a re-configurable mu-metal magnetic shielding enclosure is planned. This enclosure will allow different magnet designs and configurations to be tested in a similar magnetic environment to the magnetic shielding enclosure that will be used in the experiment. I will discuss the design and function of the magnetic test enclosure.