Conceptual design of in-vessel divertor coils in DTT

The Divertor Tokamak Test (DTT) facility will be equipped with in-vessel divertor coils able to locally modify the flux surfaces in the divertor region. When the first DTT divertor had not been selected, four in-vessel divertor coils were considered, with 10 turns each, fed by independent 4-quadrant SCR (thyristor) 0.5 kV -5 kA -power supplies. This configuration was able to meet the design criteria in terms of requested performance and oper-ational constraints, but one of the coils is not compatible with the geometry of the first DTT divertor, and another coil, scarcely efficient, can be removed. This paper discusses the design criteria, illustrates the possible revised layout, and illustrates the performance that can be achieved.