Ramp rate experiments on a Nb/sub 3/Sn CICC wind-and-react magnet

The central solenoid of ITER 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 loss, could occur in CIC conductors. Such ramp rate limitations have to be well understood in order to be avoided in the ITER conductors. The ENEA Nb/sub 3/Sn solenoid is a 1 m OD, 0.6 m ID coil, made of a CIC conductor which is a factor 8 smaller than the ITER full size cable. The total conductor length, 750 m, is ITER relevant. An experimental setup has been assembled, allowing ramp rate and DC tests on the ENEA coil up to 8 T, 2-4 T/s, 12 K. Main objectives of the program are experimental data on ramp rate limitation, pulsed current distribution in the s/c cable, limiting currents and global AC loss. This paper reports the results of the measurements carried out up to now.