Chavis T. Raynor

Evidence of inverse bremsstrahlung in laser enhanced laser-induced plasma

Plasmas created by a Nd:yttrium aluminum garnet laser show systematic changes in local electron temperature when bathed by a continuous wave laser of increasing irradiance. By monitoring the local electron density, the laser light absorption coefficient, and the signal to noise ratio in neutral emissions, we explain the changes in electron temperature and signal to noise to be a consequence of inverse bremsstrahlung in this new system of laser enhanced laser-induced plasmas.

Critical turbulent energy reductions in plasmas using weak magnetic fields

With an arc-driven shock tube, laser induced fluorescence, and a multipoint density diagnostic technique, we study the turbulence behind an ionizing shock wave in the presence of a magnetic field. The magnetic field is directed either parallel to or antiparallel to the direction of the shock wave’s propagation, and is configured in such a way as to couple with turbulent velocity fluctuations in the plane perpendicular to the direction of flow. We find that the magnetic field can be used to reduce the turbulent energy in a plasma system. Further, when the evolution to turbulence is treated as a second-order phase transformation, the critical turbulent energy decreases with increasing magnetic field.