Neutron EDM Project High Voltage Tests

The nEDM@SNS project will search for the Electric Dipole Moment of the neutron at a level of 3 x 10-28 e-cm, about a factor of 100 more sensitive than the current upper bound, using a unique cryogenic method. The experiment measures the precession frequency of free ultracold neutrons’ spin in the presence of a combined low magnetic and very high electric field. The experiment uses 1200 liters of superfluid helium simultaneously to cool the neutrons, to hold off the necessary high voltage, and as a neutron detector.

Recent tests conducted at Los Alamos National Lab have demonstrated the ability to deliver the required 200 kV high voltage to the 0.7 K cryogenic heart of the apparatus, immersed in superfluid liquid helium.

This new result enables an ongoing testing program to develop the high voltage cryogenic equipment required for the ultimate experiment.