Activities on realization of high-power and steady-state ECRH system and achievement of high performance plasmas in LHD by Shimozuma, T, Kubo, S, Yoshimura, Y, Igami, H, Takahashi, H, Ikeda, R, Tamura, N, Kobayashi, S, Ito, S, Mizuno, Y, Takita, Y, Mutoh, T, Minami, R, Kariya, T, Imai, T, Idei, H, Shapiro, M, Temkin, R, Felici, F, Goodman, T, Sauter, O