Spatial response of symmetric and asymmetric planar SQUID gradiometers

First and second order symmetric gradiometers, and first order singly and doubly asymmetric gradiometers have been designed and fabricated using a standard niobium thin-film process. Here we present the results of our simulations of the effect of varying the gradiometer geometry, order and symmetry. In particular, we are interested in the spatial response of the gradiometer. We compare the simulations with experimental data.