Quench induced helium flow and recovery in the euratom LCT coil

A numerical model was developed to simulate the behaviour of a normal conducting section in a forced flow cooled superconducting cable. Two involved problems are solved simultaneously, (a) the instationary compressible helium flow problem in a heated duct, (b) the power balance of heat generation in the conductor and heat removal by heat transfer to the coolant and by axial heat conduction. For the EURATOM-LCT-coil the behaviour with time of a number of initial perturbations of different length is presented. It is shown clearly that for long zones the growth or decay of a normal zone is dominated by the induced helium flow. Zones with a length of one turn or more disappear within 80 msec. Shorter zones lead to a quench. Variation of the magnetic field along the conductor is shown to enhance the recovery capability.