Heat erosion of the graphite target under effects of intensive pulse plasma flow

Abstract

In this work the results of an experimental investigation of the interaction of a pulsed plasma flow with a candidate material – graphite plates of the first wall of ITER are presented. To generate a pulsed plasma flow, as well as to simulate and experimental modeling the breakdown of a plasma flow on a wall, an experimental setup pulsed plasma accelerator was used in this work. Graphite plates were irradiated with 25 pulses of plasma flow. On the basis of electron-force microscopy, SEM images of graphite samples were obtained after exposure to a series of pulsed plasma flow in two different discharge voltages of 5 kV and 11 kV. The Raman spectrum of the initial samples are also shown, and optical diagnostics of the surfaces is performed. According to the Raman spectrum, it was found that samples of graphite in both cases have a defective structure. The experiment also found that copper films are formed on the surface of graphite plates, this is mainly due to the deposition of copper molecules, ejected from the surface of the electrodes during ignition of the arc discharge in the interelectrode space. The results are well studied, analyzed and compared with the results taken in the ITER.