Experimental Dipole to Test for Current Redistribution in a REBCO Tape-Stack Cable

Recent theoretical studies have suggested the feasibility of using a non-insulated, non-transposed REBCO tape-stack cable in a high-field dipole winding. Variation in magnetic field across the tape-stack induces a redistribution of current as the cable current is increased. As each tape approaches its critical current, the dynamic rise in tape resistance drives currents to redistribute preventing premature quench. A lumped network circuit model coupled with magnetic field simulation has been used to predict the dynamics. A small-scale model dipole has been designed to experimentally study current redistribution in a model dipole containing a racetrack tape-stack REBCO winding. The model dipole will operate at liquid nitrogen temperature with a central field of ∼0.25 T. The predicted dynamics for current redistribution are similar to what is expected in the REBCO insert winding for a high-field hybrid dipole.