Magnetic Field Design for Spin Transport in 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 $4\times10^{-28}$ e-cm, 100 times better than previously existing measurements that have only set an upper limit on the value of the nEDM. This experiment requires a uniform magnetic field around the measurement volume, and the transport of the polarized He-3 into the measurement volume. I will talk about the magnetic field design for the magnetic shielding room that will house the experiment, and the design of the additional magnets that are used for the transport of polarized He-3 into the measurement volume while maintaining the uniformity of the magnetic fields in the interior of the magnetic shielding room.