Radiation environment in ITER tokamak equatorial port 11

The work is devoted to modeling of the radiation environment in the equatorial diagnostic port 11 of the ITER tokamak including Port Plug, Interspace, and Port Cell areas by the Monte Carlo method. The axial symmetry of the torus allows to make the nuclear analysis in the toroidal 40 degrees sector of the ITER model. Periodic boundary conditions were specified on the sides of the simulated ITER sector, which reflects the symmetry of the calculation model. The DT-plasma in the main mode of tokamak operation is used as a neutron source with a fusion power of 500 MW and an intensity of 2 & sdot;1019 n/s. An additional surface source of neutrons is introduced to estimate the loads on the diagnostic equipment in the ITER Port Cell. The results of computer simulation of radiation fields and absorbed dose in the equatorial port 11 of ITER are presented. The radiation effect of thermonuclear DT-plasma on the elements of ITER diagnostic systems is considered. The results show that neutron and gamma irradiation emanating from the fusion plasma do not cause significant damage to the H-alpha diagnostic components.