Stability of cable-in-conduit internally cooled superconductors subject to local disturbance

A likely source of a quench in cable-in-conduit internally cooled superconductors (CCICS) is frictional heating due to strand motion in the cable. Most previous studies on CCICS stability evaluate the amount of energy needed to quench the conductor by assuming that the disturbance energy is uniformly distributed across the cross section. We believe that these studies are too optimistic, and have studied the stability of CCICS assuming that the disturbance energy is abruptly input into a small part of a single strand. To perform this analysis, the transient heat transfer characteristics of supercritical helium (SHE) have been measured. This paper presents the transient heat transfer characteristics of SHE and the results of our stability analysis