Investigation of stability in cable-in-conduit conductors with heat pulse durations of 0.1 to 1 ms

The stability of NbTi/Cu cable-in-conduit conductors was experimentally investigated at the very fast heat pulse duration of around 1 ms being near actual time duration of strand motion and plasma disruption. Three kinds of the test samples were prepared with different copper volume fractions in the strand. As heater, a single pulse inductive method was used so as to accurately calculate an input energy. Experiments were carried out at zero flux rate, pressures of 3 to 9 atm and 4.2 K. The measured stability margin of all conductors were lower than the available enthalpy difference of the helium. The limiting current were observed even in the heat pulse durations of around 1 ms. It was found that the limiting current density over cable space was expected to be more than 50 A/mm/sup 2/ at 8 T and 6.5 atm