Thermal contact conductance between the bundle and the conduit in cable-in-conduit conductors

Temperature rise in a quenching cable-in-conduit conductor is strongly affected by thermal contact conductance between the bundle and conduit. To evaluate this temperature rise, conductance is measured by using two experimental techniques. In the first experiments, we apply a current to a short conductor cooled to liquid nitrogen temperature and observe the temperature rise of the bundle and conduit. The conductance is calculated from the temperature difference. In the second experiments, contact conductance is directly measured under compressive pressure at room temperature by using a small copper block with heaters. The results show that the contact conductance is affected by surface pressure and is almost independent of the conductivity of ambient gas. Therefore, to evaluate temperature rise in a quenching conductor, it is necessary to measure conductance under a surface pressure equivalent to an electromagnetic force.