Westmijze's 'thin' gap head revisited

An analysis of Westmijze's thin gap head which is useful because it leads to the formulation of an algorithm for the noniterative calculation of regular semi-infinite gap head fields accurate to better than any specified error is described. With regard to the practical realization of heads with the thin gap head field configuration, it is shown that two potentially interesting devices would become possible if superconducting materials with ideal diamagnetic properties could be used in their construction. A variation of the resistance paper technique for measuring the fringing field configuration of heads containing superconducting materials is described. The very-high-permeability material is simulated with very-high-conductivity metal foil or paint, and the unit permeability regions are represented by the resistance paper itself. The superconducting regions of the head structure may be simulated perfectly by cut-outs in the resistance paper. The cut-out regions, having infinite electrical resistance, simulate correctly the perfectly diamagnetic superconductive regions.<>