Normal zone propagation and quench characteristics of Nb/sub 3/Sn wires with jelly-roll and in-situ processed CuNb reinforcements

Abstract

The stability of three types of CuNb reinforced Nb/sub 3/Sn wires has been experimentally studied in order to clarify effects of critical current density, J/sub c/, and Nb fraction in CuNb reinforcements. The stabilities, i.e., minimum quench energy, MQE, and normal zone propagation velocity, "/sub p/, were evaluated for sample wires having low J/sub c/ and low Nb fraction (A) and high J/sub c/ and low Nb fraction (B) with in-situ processed CuNb reinforcement and high J/sub c/ and high Nb fraction with jelly roll processed CuNb reinforcement (C). The MQE decreased with increase in transport current density normalized by J/sub c/, critical generation density, and Nb fraction, on the other hand, /spl nu//sub p/ increased with increasing the transport current density, regardless of Nb fraction. We obtained basic data for the design of magnets having both a high stability and mechanical strength.