Thomson scattering of plasma turbulence on PSI-2

Highlights: • Time-resolved Thomson scattering developed at linear plasma generator. • Photon counting and conditional averaging allow resolving intermittent plasma events. • Temperature oscillation identified in Argon discharge. • Intermittent events analyzed in Deuterium discharge. - Abstract: The turbulent transport in the edge of fusion reactors can be conveniently simulated by linear plasma devices with long duty cycles. At high input power steady state plasma discharges at PSI-2 exhibit intermittent fluctuations similar to the edge of toroidal plasma devices. As their influence on erosion predictions is obscured by time-averaged measurements a time-resolved Thomson scattering setup is installed and tested at PSI-2. Aided by a fast CMOS camera and conditional averaging a time resolution of 3 µs was achieved for temperature and density profile evolution in Argon and Deuterium discharges. A 40 kHz, m = 1 oscillation with 50 µs coherence time and 1 eV electron temperature amplitude was identified in Argon, while in Deuterium intermittent events were associated with a 4 eV rise in edge temperature and a 10% reduction of bulk density.