DTT Thermal Shield: system integration and procurement

DTT is one of the largest superconducting tokamaks with the mission to get scientific and technological proofs of power exhaust in prospect of the first nuclear fusion power plant. Superconducting magnets (poloidal field coils, toroidal field coils, and central solenoid) to reach the superconducting state will be cooled down to 4.3 K by means of supercritical Helium. The function of the thermal shield system is to intercept the radiation heat loads from the machine warm components (Vacuum Vessel, Ports, and Cryostat) to the superconducting magnetic system. The thermal shield consists of a series of actively cooled panels to be installed into the small gaps between the warm and ultra-cold components, also assuring an adequate clearance towards each interface, for any machine operating state. The paper describes the rationale for the thermal shield gravity supports based on a robust mechanical anchoring system to withstand static and mechanical loads, reducing, at the same time, the magnitude of heat flux towards the fastening interface. Further, the positioning and installation sequences are described during the machine assembling operation. In perspective of procurement phase, the main manufacturing requirements are addressed in terms of panel manufacturing, tube welding and surface finishing to optimize the shielding effectiveness of the component.