Effect of wall shape on the loss of alpha particles in ITER with TBMs

Tani, Keiji*; Shinohara, Koji; Oikawa, Toshihiro*; Miyamoto, Seiji

The benchmark test proposed at the last ITPA E-P meeting about the heat load on the first wall due to loss alpha particles in ITER with TBMs (Test Blanket Modules) was executed. In relation to the benchmark test, the effect of wall shape on the loss of alpha particles was also investigated. The benchmark test shows that the total power loss is as low as about 0.2%. Related studies show that the heat load is very sensitive to the wall shape and that a poloidal limiter in the axi-symmetry loss region on the first wall is very effective to reduce the local heat load near TBMs.