Growth of nanostructured highly porous surface on refractory metals under plasma treatment in the PLM device

Refractory metals are irradiated with powerful plasma in the PLM plasma device which is a linear magnetic trap with a 8-pole multicusp magnetic confinement. A feature of this device is the many hours stationary confinement, which is an advantage for testing materials of the divertor and wall of a thermonuclear fusion reactor and for the development of novel plasma technologies for metal processing. Helium plasma parameters were measured in the PLM by using the reciprocated Langmuir probe. Tungsten, titanium and molybdenum test plates were tested in stationary helium discharges in the PLM during 200 minutes. The thermal load on the surface of the test plates was more than 1 MW / m2. The temperature of the plates reached 1000 °C. Scanning electron microscopy analysis revealed a stochastic nanostructured surface with dimensions of structural elements less than 100 nm. Such materials are of interest for using in nuclear, chemical and biomedical technologies.