INVESTIGATION OF ELECTRON-PROTON DRIFTS WITH THOMSON SCATTERING

We present a detailed investigation of asymmetric ion features of Thom son scattering spectra observed in the compression phase of a gas-line r pinch discharge. The asymmetries can be explained by drift velocitie s between electrons and ions, and an appropriate form factor taking in to account drift velocities and different atomic species in the plasma can be fitted to the detected spectra. By varying the scattering volu me in the midplane of the discharge the magnitude and direction of the drift are measured. These results and pinhole pictures of the whole p lasma column show that the drifts are produced by Rayleigh-Taylor inst abilities resulting in high radial current density components of the d ischarge current. (C) 1996 Elsevier Science Ltd.