Neutronics analysis of the in-vessel components of the ITER plasma-position reflectometry system on the low-field side

Abstract

The ITER Plasma Position Reflectometry (PPR) system will be used to estimate the distance between the position of the magnetic separatrix and the first-wall at four pre-defined locations. For gap 4, the antennas are to be installed in-vessel between two blanket shield modules. The antennas and adjacent waveguides are directly exposed to the plasma through cut-outs in the blanket modules and are therefore subjected to high radiation doses from neutrons and photons, which may cause irradiation-induced changes in the material properties and compromise the integrity of these components. Here, we report on the neutronics analysis of the PPR system of gap 4 performed with the Monte Carlo simulation code MCNP6, with the objective of estimating the thermal loads in the system. The nuclear loads obtained in the neutronics analysis will be used as input in the thermal analysis of the in-vessel components of the ITER PPR system.