Type I ELM control by pellet injection in ITER

Sugihara, Masayoshi; Polevoi, A.*; Fujieda, Hirobumi*; Shimada, Michiya; Yoshino, Ryuji

Pellet injection is one of the strong candidates for Type I ELM amplitude control. In ITER, this scheme has been selected as a first candidate method to suppress the amplitude. In order to provide the physics specification for this scheme in ITER, following issues are investigated; (1) required penetration depth of the pellet to trigger the ELM, (2) compatibility with particle transport and density control, (3) dependence of injection direction (high field or low field side). Operation spaces for each injection direction are evaluated based on these investigations and the necessary physics specifications are derived.