High-Speed Visible Imaging of the Central-Cell Plasmas in the GAMMA 10 Tandem Mirror

抄録

Details of two-dimensional imaging performed in the central-cell of the GAMMA 10 tandem mirror by using high-speed camera are described. At the GAMMA 10 central-cell midplane, a high-speed camera (MEMRECAM fx-K4, NAC Inc.) was mounted and the shape and the motion of plasmas were precisely investigated. In the standard ion cyclotron range of frequency (ICRF) heated plasmas, gas puffing of hydrogen with short pulse (3-5 ms) close to the central-cell midplane was carried out to illuminate the periphery plasma and the time evolution of visible light emitted from the gas was captured. The Hα line-emission was localized close to the port of gas puffer. In the pellet injection experiments, 2-D images of the ablation light induced by hydrogen ice-pellet injection were successfully captured at the GAMMA 10 central-cell. Analysis of 2-D images clarified that the electron cyclotron heating applied in the central-cell (c-ECH) has a significant influence on the edge plasma turbulence and the ablation of hydrogen ice-pellet.