Thomson scattering on transient microwave induced plasmas

In this study we investigate a pulsed microwave discharge at low pressure using time resolved Thomson scattering (TS). The plasma is surface wave induced, launched by a surfatron device. That provides a spatially extended plasma coloumn with well-known properties. A frequency doubled Nd:YAG laser is focused in the plasma detection volume. The scattered photons on free electrons were detected, using a sophisticated spectrometer setup to reject the laser wavelength. Due to the high temporal and spatial resolution of this laser scattering techniques we were able to measure the immediate response of the electron density and temperature on power pulsing for various pulse lengths and frequencies. Conclusions about the recombining nature of the decay process could be drawn.