Spectroscopic investigations of the magnetic field evolution and plasma flow in a microsecond POS

Spatially resolved measurements in a planar microsecond POS, using spectroscopy of dopants, in the plasma, are presented. The magnetic field evolution, determined from Zeeman splitting, is mapped in 2D and found to propagate axially at an average velocity of 3.3/spl times/10/sup 7/ cm/s. The axial velocities of various ions are determined and found to be less than the propagation velocity of the magnetic field. The electron density determined from the temporal behavior of various spectral lines is found to drop after the magnetic field reaches 60% of its peak value.