Simulation experiment of thermal transient events in ITER by use of magneti zed coaxial plasma gun

A compact-sized MCPG with a single discharge stage is developed so as to simulate transient heat loads such as type I ELMs in ITER. The MCPG produces H₂ plasma with the electron density of 1-4 times 10²¹ m^-3, the ion energy of 15 eV and the pulse width of 0.5 ms. It is found that the absorbed energy density measured by a calorimeter reaches 0.9 MJ/m² which is comparable to transient heat load of type I ELMs expected in ITER. Erosion of tungsten due to the plasma irradiation produced by the MCPG was confirmed only at the edge parts of the specimen.