Magnetic Field Simulations for the n2EDM Experiment at Paul Scherrer Institute

Precision spin-precession experiments like searches for the neutron electric dipole moment (nEDM) place stringent requirements on the magnetic field. We present a global simulation of a magnetic field map in and around the six-layer magnetic shield room (MSR) of the n2EDM experiment, a large multinational endeavour to measure the nEDM with a statistical sensitivity of $1\times10^{-27}~e\cdot$cm. In addition to the precession field and spin transport coils, our simulation takes into account nearby superconducting coils and a high-performance active magnetic shielding system. We describe techniques used to characterize measurements of these coils, integrating them with backgrounds fields into the environment of the MSR. This simulation will be used to optimize spin transport of UCNs in and out of the Ramsey measurement cell, and to study the effect of external fields on the experimental sensitivity.