Laser-produced plasmas interaction with high pulsed magnetic field

This work presents results of two experiments accomplished at the Institute of Plasma Physics and Laser Microfusion (IPPLM) in Warsaw: (1) investigati ons of the influence of magnetic field on a laser-produced plasma in the pr esence or absence of the background plasma, (2) investigations of dynamics of laser-produced plasma in a strong magnetic field. The aim of experiment 1 (performed in collaboration with the Institute of Laser Physics (ILP) RAS , Novosibirsk, Russia) was laboratory simulation of depolarization and defl ection of plasma streams drifting across magnetic field in geoplasma backgr ound. An Nd:glass laser (5 ns, 2 J) was used to produce the plasma inside H elmholtz coils (B less than or equal to 2 T). The diagnostics for studying the interaction processes were: ion collectors, Langmuir and magnetic probe s and an image converter camera. We present a comparison of the effects inv estigated in that experiment with some phenomena occurring in the geoplasma . In experiment 2 the plasma was produced by means of a Nd:glass laser (1 n s, 10 J) focused on a solid target located in a single-turn coil (B < 20 T) . Plasma expansion was investigated with an automated interferometer along the magnetic held lines and perpendicular to these lines. From the interfer ograms, it has been revealed that the plasma stream has a clear asymmetry f or t > 10 us caused by an unmagnetized ion Rayleigh-Taylor instability.