Application of Quasi-Steady-State Plasma Streams for Material Studies

The paper presents experimental studies of material response to high power plasma irradiation simulating ITER divertor heat loads. The experiments were performed with QSPA repetitive plasma pulses with the duration of 0.25 ms and the energy density up to 2.5 MJ/m2. Surface morphology of the targets exposed to QSPA plasma screams is analyzed for impacting plasma loads both below and above the melting threshold. Relative contribution of the Lorentz force and plasma pressure gradient to the melt layer erosion is discussed. Development of cracking on the tungsten surface and swelling of the surface are found to be in strong dependence on initial temperature of the target