Articles techniques et présentations

State of the art measurements of permanent electric dipoles (EDM) measure accumulated phase in spin-polarized gases over hundreds of seconds and are exquisitely sensitive to magnetic field inhomogeneities. The search for the neutron's EDM at Los Alamos National Laboratory (nEDM@LANL) will measure ultracold neutrons (UCN) and mercury vapor simultaneously, allowing some of these defects to be ignored. Traditional coil winding patterns are optimized for magnetic fields and gradients along a single axis. Because both gaseous species are free to sample a full 30 l volume during the holding time, the fields they sample also need to be made uniform over that volume.

Using an orthogonal basis expansion of the scalar potential, I have developed an iterative method to generate idealized winding patterns for a given closed surface, simulate the resulting magnetic field, and correct the windings to correct for holes in the surface, couplings to high permeability materials, and wide wire spacing. These wire patterns are readily manufactured with either CNC, large-scale plotters, or flex-PCB printing.