Magnetostatic simulations for design of superconducting magnetic shields

A magnetostatic approach to numerical simulations of magnetic field attenuation by superconducting shields is demonstrated on simple geometries. Comparisons to published measurements and analytic calculations show that results are accurate for simulation of a shield in the shape of a cylindrical tube. The capabilities of the method are shown by simulations which close the cylinder with end caps having access ports or gaps. With end caps having cylindrical ports, the simulated attenuation transits smoothly between the analytical results for semi-infinite tubes of the two radii. Radial gaps between solid end caps and the cylinder allow little flux leakage for time-varying fields, but significant leakage for static fields.