The motional Stark effect: Overview and future development (invited)

As an atomic beam propagates across a magnetic field, an electric field is generated, E = V X B. This results in a spectral splitting and polarization of the emitted radiation, known as the Stark effect. The direction of pola rization of the emitted radiation provides a measure of the local magnetic field direction or pitch angle. In addition to the electric field generated by the neutral beam, intrinsic electric fields present in the plasma affec t the direction of polarization. This has been exploited to measure both th e plasma electric field and the magnetic field. Future development of the m otional Stark effect utilizing laser induced fluorescence to access much lo wer magnetic fields will be discussed. (C) 1999 American Institute of Physi cs. [S0034-6748(99)50901-5].