Stability and quench behavior for pulsed tests on ENEA 12 T Nb3Sn CICC coil

Abstract

The Central Solenoid (CS) of ITER (International Thermonuclear Experimental Reactor) is designed to operate at 13 T, 0.5-1 T/s, 5.8 K. There is an experimental evidence that reduced performances in variable field, not explained by AC losses, could occur in CIC (cable-in-conduit) conductors. Such ramp rate limitations have to be well understood in order to be avoided in the ITER conductors. In the ENEA Frascati Laboratory a facility has been assembled to test in pulsed regimes (up to 8T, 4 T/s, 12 K) the ENEA Nb3Sn CICC coil. The characteristics of the coil (dimensions, CIC conductor, strand designed for use in variable field). Main objectives of the program are experimental data on ramp rate limitations, pulsed-current distribution in the cable, limiting currents and global AC losses. This paper reports the results of the measurements carried out up now, and those of the simulations performed by means of the thermo-hydraulic analysis code SARUMAN.