Optical magnetometer development for the Los Alamos neutron EDM experiment

The Los Alamos National Laboratory neutron electric-dipole-moment experiment (LANL nEDM) is designed to measure the neutron EDM with a statistical uncertainty of 2e-27 e-cm with ultracold neutrons stored in paired bottles with opposite electric fields. This sensitivity requires controlling and measuring the magnetic fields and magnetic-field gradients to achieve the statistical sensitivity and mitigate systematic effects that couple to motional magnetic fields (vxE). Optically-pumped 87Rb magnetometers based on a pump-probe sequence that routinely achieve <200 fT/√Hz precision and <200 fT stability for 10-100 seconds at 1 µT have been developed and will be deployed near the neutron-storage bottles. This talk will describe extensive studies of the magnetometers and how they are used in the LANL nEDM experiment.