CHARACTERIZATION OF A LASER PLASMA IN A PULSED MAGNETIC-FIELD .1. SPATIALLY RESOLVED EMISSION STUDIES

The effect of a pulsed magnetic field on spatially resolved emission from a laser plasma at atmospheric pressure was investigated. The pulsed magnetic field, produced by capacitive electrical discharge through a specially designed solenoid, was oriented normal to the laser axis. Temporally integrated emission enhancements due to the magnetic field were found to be most significant when the plasma was formed about 1 mm below the magnetic field axis. The degree of confinement of the plasma increased with magnetic field strength-these studies utilized the maximum magnetic field attainable with this system that did not jeopardize the structural integrity of the solenoid (approximately 85 kG). Laterally resolved emission characteristics (observed both along and normal to the magnetic field axis) demonstrated significant radial compression and axial expansion of the laser plasma. These effects are explainable by JxB or fluid magnetic pressure interactions. Further deconvolution of dynamic magnetic field effects on plasma atomization/excitation/ionization characteristics require spatially and temporally resolved emission and absorption studies.