Refractive optical measurements on the Llampudken generator

Abstract

Experiments with two different configurations of dense z-pinches have been carried out on the Llampudken generator with the objective of investigating the time evolution of the discharges. These configurations were studied with refractive optical measurements using the second harmonic of a Nd:YAG laser (10 ns FVVM lambda=532 run). The Llampudken generator delivered a pulse current of 450 kA with a 260 ns rise time. Refractive optical measurements with schlieren diagnostics were made using an optical system which provided two frames per discharge. The original beam was split into two separate beams with perpendicular polarizations using a polarizer beam splitter and an extra path length was introduced into one of the beams delaying it with respect to the other. The path through the discharge chamber was equal for both beams therefore providing identical views of the plasma at two different times. The images were recorded on 35mm cameras using suitably orientated polarizers to select the corresponding beam. As a complementary diagnostic technique, MCP cameras with exposure time of 2 ns were used to obtain VUV images of the loads. Preliminary results of these experiments will be presented and discussed.