Abstract
We present a coil system designed to generate a highly uniform magnetic field for the n2EDM experiment at the Paul Scherrer Institute. It consists of a main B0 coil and a set of auxiliary coils mounted on a cubic structure with a side length of 273 cm , inside a large magnetically shielded room (MSR). We have assembled this system and characterized its performances with a mapping robot. The apparatus is able to generate a 1 μT vertical field with a relative root mean square deviation σ(Bz)/Bz = 3 × 10-5 over the volume of interest, a cylinder of radius 40 cm and height 30 cm . This level of uniformity overcomes the n2EDM requirements, allowing a measurement of the neutron Electric Dipole Moment with a sensitivity better than 1 × 10-27e cm .