Stability in a long length NbTiCICC

A crucial issue for a superconducting coil in order to be safely used in th e magnetic system of a fusion reactor is stability against all foreseen dis turbances. To simulate the fusion machine conditions, including off-normal events, e,g, plasma disruptions, the energy deposition has to be spread ove r a "long length" Cable In Conduit Conductor (CICC) and a background magnet ic field is needed. We have therefore designed and built an experiment cons isting of an instrumented NbTi test module inserted in a pair of co-axial p ulsed copper coils. A 0.6 m diameter superconducting coil provides a backgr ound magnetic field up to 3 T. Calibration of the energy inductively coupled between the pulsed coils and the module has been obtained measuring the system temperature increase just after the pulse by means of thermometers positioned along the conductor. Stability vs. operating current I-op has been examined for different helium temperatures and different background magnetic fields. The finite element code Gandalf for the stability and quenching transients analysis in forced flow cooled superconducting coils has been run to check the matching with the experimental results.