Comparison of Spin Manipulation with Spatially Oscillating Longitudinal or Transversal Magnetic Fields

Sona-transition units have been used since 1967 to conduct non-adiabatic transitionsbetween Zeeman states. Their energy levels depend on the external magneticfield. This means that spins and the external magnetic field have an oppositerelative orientations after the particle beam passed through the Sona-transition region,which is an area of rapid inversion of the B-field. The Zeeman states willbe changed as well, because they are equivalent to combinations of electron- andnuclear-spin orientations. In experiments an unexpected effect had beenobserved though, that presented itself as oscillations of the measured intensitiesor polarizations when changing the magnetic field strength in the Sona-transitionregion. Only quite recent, this effect could be explained: The spatially oscillatingmagnetic field of the Sona-transition unit acts on passing atoms as coherentphotons. Here the magnets are aligned parallel to the beam line with a primarylongitudinal magnetic field. The photon-like interaction between atoms and theB-field is mainly caused by the higher order radial component of the magneticfield. Therefore, a new setup with magnetic fields orthogonal to the beam linewas developed. This new transversal Sona-transition unit consists of two coilpairs to produce opposing magnetic fields and was tested by varying several parameterslike the distance from the beam axis to the coils or the position alongthe beam line. The corresponding results confirm simulations that are made inparallel for this new magnetic field configuration. Thereby, it was observed thatjust one coil pair and its transversal magnetic field is already enough to inducetransitions within the hyperfine states.