Normal Zone Propagation in YBCO Winding Pack Models

This paper presents the results of a study, experimental and simulation, of normal zone propagation (NZP) in winding pack models comprised of several lengths of YBCO tapes, each sandwiched by insulating spacers. A heater strip extending over the entire length of, and placed at the midpoint of, each winding pack model was energized over the entire length to trigger a quench in the middle YBCO tape. In each winding pack model, the YBCO tapes were connected electrically in series in such a way that a transport current through the YBCO tapes zigzagged from the YBCO tape at one side of the winding pack model to that at the other side of the winding pack model. The transverse speed of normal zone propagations through the different insulating spacers were measured by experiments and estimated by simulations.