Magnetic Shielding in the nEDM Experiment at Los Alamos National Laboratory

The search for the neutron electric dipole moment (nEDM) is an ongoing project at Los Alamos National Laboratory (LANL) with the intention to improve measurement precision using techniques of room-temperature Nuclear Magnetic Resonance (NMR). The current accepted upper limit of the nEDM is |d_n| < 1.1 · 10⁻²⁶ e·cm recently published by the Paul Scherrer Institut group (2020). The nEDM@LANL effort looks to improve the measurement uncertainty to 3 · 10⁻²⁷ e·cm. A non-zero nEDM result of this sensitivity will suggest CP-violating physics beyond the Standard Model that will further our understanding of the matter-antimatter asymmetry of the universe. In order to reach this sensitivity, a magnetically shielded room (MSR) is necessary. The MSR is currently under construction at LANL; it consists of five independent layers: one layer of copper and four layers of MuMetal, an alloy with a high magnetic susceptibility. The MSR is expected to produce a shielding factor of 100,000 at 0.01Hz. In this poster, I will discuss the design principle and report on the construction of the MSR.