Tokamak – Thermal Shield

Thermal shields are installed to limit the heating of the superconducting magnets, in particular due to radiation from the cryostat and the vacuum vessel. 

The thermal shield consists of 18 segments electrically insulated from each other to prevent excessive electromagnetic forces during disruptions. The vacuum vessel (VVTS) and port (PTS) thermal shields consist of two panels reinforced by edge frames and gaseous (80K) He cooling pipes, fitting snugly in the gap between TF coil and vessel. The cryostat thermal shield (CTS) is single-walled with multilayer superinsulation.

The thermal shield is supported by the TF coils, between EF coils 5 and 6, and at the top on alternate TF coil casings.