Magnetic and mechanical AC loss of the ITER CS1 model coil conductor undertransverse cyclic loading

The magnetic field in a coil results in a transverse force on the strands p ushing the cable towards one side of the jacket. A special cryogenic press has been built to study in a unique way the mechanical and electrical prope rties of full-size ITER Cable-in-Conduit (CIC) samples under a transverse, mechanical load. The press can transmit a variable (cyclic) force of at lea st 650 kN/m to a cable section of 400 mm at 4.2 K. The jacket around the ca ble is partly opened in order to transmit the transverse force directly ont o the cable. A superconducting dipole coil provides the AC magnetic field r equired to perform magnetisation measurements with pick-up coils. In additi on the interstrand resistance (R-c) between various strands selected from t opologically different positions inside the cable is measured, The force on the cable as well as the displacement are monitored simultaneously in orde r to determine the effective cable Young's modulus and the mechanical heat generation due to friction and deformation as the force is cycled, The mech anical heat generation, the coupling loss time constant n tau and R-c of a full-size ITER conductor have been studied under load for the first time. A n important result is the significant decrease of n tau, after cyclic loadi ng. It is also observed that the mechanical heat generation decreases with cycling. (C) 1998 Elsevier Science B.V, All rights reserved.