Generalised Anderson coils for magnetic resonance imaging

Abstract

A method for generating highly linear field gradients over a large region of space is described. The coil assembly consists of two sets of n equispaced current lines laid on parallel planes whose values can be individually controlled. Field expressions are developed in Chebyshev polynomials and individual current control permits the required field profile to be achieved. Comparison between gradients obtained using conventional Anderson coils and the present ones shows a great improvement in gradient linearity, particularly when a large fraction of the coil assembly is considered.