Tungsten melt layer erosion due to J × B force under conditions relevant to ITER ELMs

The behavior of tungsten under repetitive hydrogen plasma impacts causing surface melting in conditions of an applied J × B force of up to 20 MN/m3 is studied with the plasma accelerator QSPA Kh-50. Tungsten samples of EU trademark have been exposed to up to 100 pulses simulating ITER ELMs of the energy load 0.7 MJ/m2 and the duration 0.25 ms. An electric current J flows across the magnetic field B of 1.4 T, and the resulting J × B force produces a displacement of the melt with formation of an erosion crater and an inclination of the surface profile along the force. Surface morphology and the damage by surface cracks are discussed. Comparisons of experimental results with numerical simulations of the code MEMOS-1.5D are presented.