Status of the Halo Current Sensor Project for JET-EP
Halo Currents (HCs), flowing through plasma and vacuum vessel during plasma disruptive events, induce severe mechanical stresses in the plasma facing components and in the vessel, and are a major concern for present and future fusion experiments like ITER. The new system of Halo Current Sensors (HCS) designed for JET-EP should help to evaluate HC density distribution, localization and rotation as well as toroidal and poloidal current asymmetries. The HCS system will include 4 identical mechanical structures each including: 8 Rogowski coils and 2 toroidal pick up coils. The Rogowski coils will measure directly the current flowing through some of the tiles of the upper dump plate. The toroidal field pick-up coils will estimate the total poloidal HC. The coil assemblies are installed at the top of the vessel close to secondary X point in 4 octants equally spaced along the toroidal coordinate. In this paper the design and the manufacturing of the HCS system are presented in detail.