Development and Operation of a Magnetic Impurity Scanner for the nEDM Experiment at Los Alamos National Laboratory

The aim of the Neutron Electric Dipole Moment (nEDM) experiment at Los Alamos National Laboratory (LANL) is to measure the nEDM with a sensitivity of 2x10^-27 e*cm. A nonzero nEDM would indicate CP violation while testing the validity of the Standard Model of particle physics. To achieve this sensitivity, the experiment must be carried out in a stable magnetic field with field gradients less than 0.3 nT/m. This project focused on searching for small scale sources of magnetic field inhomogeneities, such as magnetic dipole contaminations. To ensure magnetic cleanliness of the experimental apparatus, a magnetic impurity scanner has been designed and built at LANL to scan components of the magnetic field mapper before it is used to characterize the magnetic field inside the magnetically shielded room where the experiment will be carried out. While scanning components, we reviewed magnetometer data to search for discrepancies and cleaned any parts which showed signs of magnetic dipole contamination. Impurity scanner design, measurement results, and scanner upgrade effectiveness will be presented.