Y. Nakashima, I. Katanuma, K. Hosoi, H. Ozawa, R. Yonenaga, Y. Higashizono, N. Nishino, M. Yoshikawa, M. Ichimura, T. Imai, T. Kariya, Y. Kiwamoto, R. Minami, Y. Miyata, Y. Yamaguchi, N. Asakura, A. Hatayama, Y. Hirooka, S. Kado, S. Masuzaki, H. Matsuura, N. Ohno, M. Shoji, Y. Ueda
Generation and Characterization of High Heat-Flux Plasma-Flow for Divertor Simulation Studies Using a Large Tandem Mirror Device
Date of publication:
22 IAEA Fusion Energy Conference, FTP/P1-33
This paper describes the detailed results of heat and particle flux generation carried out at an exit of end-mirror of the large tandem mirror device for divertor simulation studies. Along the future research plan of the plasma research center in the University of Tsukuba, new research project on the study of divertor simulation under the environment that closely resemble actual fusion plasmas is started by making use of the advantage of open magnetic field configuration. In a typical hot-ion-mode plasmas (n_e0 ~ 2x10^18 m^-3, T_i0 ~ 5 keV), measurements of heat and particle fluxes from the end-mirror have been carried out by using newly installed diagnostic unit which consists of calorimeter and directional probe at the end-mirror exit. In the case of only ICRF heating, the heat-flux density of 0.8 MW/m2 and the particle-flux density of 10^22 particles/s?m2 were achieved over the range of 6 ~ 9 cm in diameter and heat-flux density increases with the RF power. Superimposing ECH pulse of 300 kW into RF plasmas attained the peak heat flux up to 2 MW/m^2 on axis. In the application of the ECH power, the increase of the heat flux was clearly observed and the temporal heat-flux density during ECH injection is achieved to be 9 MW/m^2. This value comes up to the heat load of the divertor plate of ITER, which gives a clear prospect of generating the required heat-flux density for divertor studies by building up heating systems to the end-mirror cell. The present status of designing the device to be introduced as new divertor system and the near term research plan are also described.