Thermal analyses of the in-vessel frontends of the ITER plasma position reflectometry system

Abstract

Abstract The ITER Plasma Position Reflectometry (PPR) system will be used to measure the plasma edge density profile at four locations, complementing the magnetic diagnostics. The components studied in this paper are the antennas and 90° bends of two of the PPR reflectometers installed inside the vacuum vessel, which are directly exposed to the plasma and thus subjected to significant thermal loads that may compromise the integrity of the system. The temperature distributions in these components was estimated with steady-state and transient thermal analyses performed with ANSYS Mechanical, following the load specification for the PPR in-vessel components and guidelines for thermal analyses issued by the IO. The results indicate that the maximum operation temperatures will be well above the limit of 450 °C for the selected material (stainless steel 316 L(N)-IG) under neutron irradiation. In face of these results, it is suggested that different materials, such as a nickel-based superalloy, are considered for the manufacturing of these components.