Presentazioni e Articoli Tecnici

High precision ‘designer’ magnetic fields are needed for the latest generation of particle physics experiments, such as the search for the Electric Dipole Moment of the neutron. The shift in focus from the high energy frontier to precision measurements of these small quantities will provide sensitivity to new physics beyond the capabilities of our highest energy particle accelerators, at the expense of demanding experimental controls--for example, uniform magnetic fields with relative gradients less than 100 ppb/cm. To achieve this precision, the process of magnetic field design can be inverted from calculating the fields from fixed currents to calculating the coil windings needed to generate such target fields using boundary value problems involving the magnetic scalar potential. In fact, a coil with windings that follow the contours of the scalar potential on the boundary of each region will produce the exact field used to specify the calculation, up to discretization effects. These contours were found using the AC/DC Module of COMSOL Multiphysics^® simulation software, and extracted using LiveLink™ for MATLAB^®. Points on the equipotential curves were then modified to import back into COMSOL Multiphysics^®
as geometry to solve for the resulting field, which is used to find corrections to the coil windings. This solution was iterated, modifying the windings incrementally until a solution converged. These windings will be used to create the coils needed to produce precision magnetic fields in the next generation of particle physics experiments.