Electromagnetic and mechanical characterisation of ITER CS-MC conductors affected by transverse cyclic loading, part 3: Mechanical properties

The magnetic field and current of a coil wound with a cable-in-conduit cond uctor causes a transverse force pushing the cable to one side of the condui t. This load causes elastic and plastic deformation with friction as well a s heating due to friction. A special cryogenic press has been built to stud y the mechanical and electrical properties of full-size ITER conductors und er transverse mechanical loading. The cryogenic press can transmit at 4.2 K cyclic forces of 650 kN/m to conductor sections of 400 mm length represent ative of the peak load on a 50 kA conductor at 13 T, In order to transmit t he force directly onto the cable, the conduit is opened partly to allow the cable deformation. The force acting on the cable as well as the displaceme nt are monitored simultaneously in order to determine the mechanical heat g eneration due to friction, The mechanical loss under load is investigated f or the Nb3Sn, 45 kA, 10 and 13 T, Central Solenoid Model Coil Conductors (C SMC). The mechanical heat generation is determined from the hysteresis in t he measured curves of displacement versus applied force. The first results of the effect of some 40 loading cycles are presented and the two conductor s are compared. A significant decrease of the cable mechanical heat generat ion after loading cycles is observed.