SQUID Gradiometer System for the Neutron Electric Dipole Moment Experiment

A search for a permanent electric dipole moment (EDM) of the neutron is one of the most sensitive probes to search for new physics beyond the Standard Model of particle physics. A new experimental search of neutron EDM has been proposed with a goal of 100-fold improvement in the present experimental limit. In this experiment, polarized helium-3 atoms will occupy the same volume as the neutrons to serve as a co-magnetometer for precise corrections for ambient magnetic field drifts in order to reach the experimental goal precision. One of the two ways that will be built into the EDM apparatus is to directly measure the helium-3 co-magnetometer precession frequency with superconducting gradiometers coupled to SQUIDs. In this talk, we will present a candidate SQUID gradiometer system consistent with experimental requirements and report noise and performance studies of the SQUID system in a test apparatus.