  Cardiomagnetometry is a growing field of noninvasive medical diagnostics that
has triggered a need for affordable high-sensitivity magnetometers. Optical
pumping magnetometers are promising candidates satisfying that need since it
was demonstrated that they can map the heart magnetic field. For the
optimization of such devices theoretical limits on the performance as well as
an experimental approach is presented. The promising result is a intrinsic
magnetometric sensitivity of 63 fT / Hz^1/2 a measurement bandwidth of 140 Hz
and a spatial resolution of 28 mm.
