2D correcting of magnetic field inhomogeneities

A method of calculating shim currents is presented. The currents are evaluated in order to create a system of orthogonal magnetic fields in the entire region where a sample is to be located. Source functions used in the calculations are the double magnetic layers shaped according to the Walsh functions. Next, by applying the Gram-Schmidt process, the sequence of currents can be established. The general method is applied to a two-dimensional problem. The influence of the magnet poles is taken into account by applying the method of images. The error for an idealized model is evaluated.