DIAGNOSTICS OF PLASMA TARGET FOR ION-BEAM - TARGET INTERACTION EXPERIMENTS

The investigation of beam-plasma interaction processes requires the de velopment of plasma parameter diagnostic methods with high temporal an d spatial resolution. The basic plasma parameters to be controlled whe n measuring the ion energy losses in ionized gases are the areal densi ty of free electrons, the degree of ionization and the heavy element i mpurities during the electrical discharge in hydrogen. We present the relevant experimental results obtained by means of time-resolved, two- wavelength Mach-Zehnder interferometry based on He-Ne (lambda = 0.63 m u m) and He-Cd (lambda = 0.44 mu m) lasers. Optical emission line spec troscopy allowed us to follow the behaviour of the impurity concentrat ions with a high temporal resolution. Both methods have been used for diagnostic tests of a hydrogen plasma target.