Development of EC H&CD launcher components for fusion device

The critical issues of an EC H&CD launcher are studied for a fusion device like International Thermonuclear Experimental Reactor (ITER). The key components of the launcher in the reactor environment are a steerable mirror and a torus window. Neutron irradiation effects on bearings for the mirror and chemical vapor deposition diamonds for the torus window were investigated. No serious degradation on the rotational capability of the bearings was observed below a total fast neutron fluence (φf, E>1.0 MeV) of 1024 n/m2, which corresponds to the 10 year neutron irradiation on the bearing position in ITER. The loss tangent (tan δ=2×10−5) and the permittivity (ε=5.7) of the diamonds at 170 GHz unchanged below φf of 1021 n/m2. Bending strength of the diamonds up to φf of 1022 n/m2 was unchanged either. The fluence on the diamonds is greater than under the ITER conditions. Analyses of the steerable mirror and of the flexible cooling tube for the mirror under the ITER conditions were carried out. The maximum temperature and the induced stress in the mirror would be 393 °C and 350 MPa, respectively. A maximum stress of 230 MPa on the outer surface of the flexible tube was obtained. It is verified that those stresses are lower than the allowable stress.