Characteristics of Magnetized Coaxial Plasma Gun for Simulation Experiment of Thermal Transient Events in ITER

Abstract

A compact-sized magnetized coaxial plasma gun (MCPG) with a single discharge stage is developed in order to simulate transient heat loads such as type I edge-localized modes (ELMs) in ITER. The MCPG produces hydrogen plasmas with an electron density of 1- 4 × 10 <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">21</sup> m <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">-3</sup> , an ion energy of 15 eV and a pulsewidth of 0.5 ms. It is found that the absorbed energy density measured by a calorimeter reaches 0.9 MJ/m <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sup> which is comparable with a transient heat load of type I ELMs expected in ITER. Erosion of tungsten due to the plasma irradiation produced by the MCPG is confirmed only at the edge parts of the specimen in this experiment.