Conceptual study of DTT ICRH antenna designs optimizing remote handling strategy

Abstract

The Ion Cyclotron Resonance Heating (ICRH) antenna for the Divertor Tokamak Test (DTT) facility is expected to be not only cantilevered, radially movable and fully cooled, but also remote handled: the additional challenge of the Remote Handling (RH) from the inner of the chamber has been posed. The remote assembly and disassembly will be performed through the HYper Redundant MANipulator (HYRMAN) and clearly require the design of the linking interfaces between the remote handled parts and the components placed behind. But the development of in-vessel Radio Frequency (RF) contacts proved in the past to be very challenging, raising concerns on their long-term reliability. Therefore, the toroidal size of the current straps has been reduced to make them, and the relative RF contacts, directly pass through the Vacuum Vessel equatorial port. Thus, only the leftover geometry of the ICRH antenna frontal part should be remote handled and alternative RH strategies have been analyzed and compared. The selecting criteria have been based on the requirements to be fulfilled like the payload limit of the HYRMAN and the RF performance, and on the subcomponents functions to be guaranteed like the side straps shielding. Furthermore, the choice process has also considered technical reasons such as the number of RH operations and interfaces to robotic arms, the minimum number of cooling circuits and the flexion risk. In compliance with the chosen criteria, the most satisfying solution has been selected to be considered for the design of the gripper to be attached to the HYRMAN.