Magnetic field tomography

Neutral atoms may be trapped via the interaction of their magnetic dipole m oment with magnetic field gradients. One of the possible schemes is the clo verleaf trap. It is often desirable to have at hand a fast and precise tech nique for measuring the magnetic field distribution. We use for instantaneo us imaging the equipotential lines of the magnetic field a diagnostic tool which is based on spatially resolved observation of the fluorescence emitte d by a hot beam of sodium atoms crossing a thin slice of resonant laser lig ht within the magnetic field region to be investigated. The inhomogeneous m agnetic field spatially modulates the resonance condition between the Zeema n-shifted hyperfine sublevels and the laser light and therefore the amount of scattered photons. We apply this technique for mapping the field of our cloverleaf trap in three dimensions under various conditions.