Recent progress on design and development of the ITER equatorial EC launcher

Takahashi, Koji; Kobayashi, Noriyuki; Kasugai, Atsushi; Sakamoto, Keishi

The recent progress of the equatorial launcher design and development are presented. The launcher compose of a front shield and a port plug that three optical steering mirrors, waveguide components, internal shields and cooling pipes are installed. Toroidal steering capability of 20MW incident rf beam by the mirrors and a necessary nuclear shielding to protect the launcher components and tokamak coils are required for the launcher. It was verified that the design of the front shield withstood incremental temperature and induced stresses while EM forces on some of the shield modules were revealed large and the support structure might not tolerate enough. Therefore, the application of a slit structure or a separable first wall has sufficiently being considered. It was also found that the structure of the copper alloy plate ( 30mm in thickness) and several stainless steal tubes (inner diameter of 12mm) with flow speed of 4m/sec can remove the expected heat deposition in the mirror and tolerate the EM forces. An ultrasonic motor is a promising candidate for the steering mirror and has been applied for the mock-up of the drive system. The study of the nuclear radiation proof for the motor is under going. A counter ECCD from the equatorial port has recently being investigated. Since having both co- and cnt-steering capability is, however, not practical technically, one of three mirrors is possibly considered for the cnt-injection although the power of the co-injection is lost.