Abel C.PIN-JUNG CHIUet. al.2025-08-062025-08-062025-02-20https://scholars.lib.ntu.edu.tw/handle/123456789/731052We 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 273cm, 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 1μT vertical field with a relative root mean square deviation σ(Bz)/Bz=3×10-5 over the volume of interest, a cylinder of radius 40cm and height 30cm. This level of uniformity overcomes the n2EDM requirements, allowing a measurement of the neutron Electric Dipole Moment with a sensitivity better than 1×10-27ecm.journal article10.1140/epjc/s10052-025-13902-x