Dynamic Response Of Plasma Detachment Caused By Molecular Activated Recombination To Transient Particle Flux In Gamma 10/Pdx

The dynamic response to a particle flux in a divertor simulation plasma has been studied using electron cyclotron heating (ECH) in GAMMA 10/PDX. Hydrogen gas was supplied to the divertor simulation experimental module (D-module), and ECH was applied to the main plasma. The electron temperature (T-e) decreased, and a rollover of electron density (n(e)) was observed upon an additional supply of hydrogen gas with and without ECH, which indicates that the plasma was detached. Moreover, the intensity of H-alpha (I-H alpha) increased even though n(e) decreased with an increasing gas supply, indicating that the plasma detached due to molecular activated recombination (MAR). In the case of additional gas supply, n(e) increased, but T-e was not affected by ECH. The ionization front moved to the upstream side, and the particle flux flowing into the D-module increased with ECH. The ratio of I-H alpha to the intensity of H beta (I-H beta) near the corner of the V-shaped target increased with ECH, indicating that the MAR was enhanced near the corner. The intensity of the Fulcher-alpha Q1-branch increased near the corner of the V-shaped target with ECH, indicating that the density of hydrogen molecules was reduced by hydrogen recycling. (C) 2019 The Japan Society of Plasma Science and Nuclear Fusion Research