  We present a spectroscopic method for mapping two-dimensional distributions
of magnetic field strengths (magnetic scalar potential lines) using CCD
recordings of the fluorescence patterns emitted by spin-polarized Cs vapor in a
buffer gas exposed to inhomogeneous magnetic fields. The method relies on the
position-selective destruction of spin polarization by magnetic resonances
induced by multi-component oscillating magnetic fields, such that magnetic
potential lines can directly be detected by the CCD camera. We also present a
generic algebraic model allowing the calculation of the fluorescence patterns
and find excellent agreement with the experimental observations for three
distinct inhomogeneous field topologies. The spatial resolution obtained with
these proof-of-principle experiments is on the order of 1 mm. A substantial
increase of spatial and magnetic field resolution is expected by deploying the
method in a magnetically shielded environment.
