Radially and axially resolved Thomson scattering in a gas-liner pinch

We performed spatially and temporally resolved Thomson scattering in a plasma generated in a gas-liner z -pinch, where the amount of axially distributed impurity ions seeded in a hydrogen plasma can be controlled. The parameters of the plasma electron density, temperature, concentration of impurity ions as well as the bulk velocity of the plasma are measured along both the radius and the z -axis. The temporal behaviour is studied from shot to shot. Depending on the impurity concentration on the axis and the kind of impurities, the homogeneity and stability of the plasma column along the z -axis are investigated. For small impurity concentrations the impurity ions are located in the homogeneous central part of the plasma offering excellent conditions to test theories on Stark broadening of spectral lines. Modulations of the density and temperature along the axis start to rise when the concentration of the impurity ions exceed a certain limit depending on their charge number. The modulations are related to Rayleigh-Taylor instabilities growing during the late phase of the compression.