Analysis of thermal and structural responses of a new diagnostic probe to repeated exposure in ASDEX upgrade tokamak

Abstract

Abstract Thermal and structural responses of a new diagnostic probe inside the AUG (ASDEX Upgrade) tokamak has been analysed numerically. This new reciprocating probe has been developed as a multi-diagnostic device for measuring several plasma parameters simultaneously. It is constructed as a universal probe that can be used in different tokamaks by applying corresponding adapters. The probe head design has to go through a number of tests (numerical and experimental) before it can be used in the actual tokamak environment, where it has to withstand repeated exposure to energetic particle fluxes in the scrape-off layer plasma. In this respect, the probe resilience to the heat loads in AUG has been investigated numerically. The performed transient analyses correspond to a typical triple insertion of the probe head into the plasma during a plasma discharge experiment in AUG. Thermal and mechanical responses of the most critical parts of the probe have been analysed. To avoid the potential pollution of the vacuum vessel, thermal resistance and structural integrity of the probe`s protective shroud have been studied in particular. The protective shroud has been constructed specifically for AUG. The simulations have shown that the shroud is able to withstand the expected plasma exposure and provides sufficient protection for the probe diagnostic and structural parts.