Stochastic nanostructure and fuzz-like structure formation on the material surface under powerful plasma load in the plasma linear multicusp device

Abstract

Abstract The plasma linear multicusp (PLM) device was constructed to test materials by powerful plasma loads. The facility is a linear magnetic trap with an 8-pole multicusp magnetic plasma confinement. In the PLM, the electron temperature of the hot and cold fraction is of 50 and 10 eV, the electron density—2 × 1018 m−3, the stationary plasma confinement is up to 200 min and more, which is an advantage for testing materials of the divertor and first wall of a fusion reactor. Tungsten, molybdenum, graphite, iron were tested in stationary helium discharges in the PLM with the thermal load more than 1 MW/m2. The temperature of the tested plates reached 1000 °C and more. A stochastic nanostructured surface and fuzz-like structure with fibers of less than 50 nm in a diameter were observed on the surfaces irradiated by hot plasma.