QUENCH ANALYSIS OF LARGE SUPERCONDUCTING MAGNETS .1. MODEL DESCRIPTION

In large superconducting magnets built using force-flow cooled conductors, such as those being designed for next generation fusion machines, the quench propagation is a three-dimensional phenomenon. In this paper we develop a method for the analysis of quenches in 3-D which is extremely versatile and comprehensive. The method is based on the parallel solution of a set of 1-D problems represented by the helium flow, heat conduction and quench propagation along the conductor length. Transverse heat exchange among conductors is then explicitly inserted in the model, thus achieving the desired 3-D capability. In the model developed for the 1-D analysis we have foreseen the possibility of taking into account the thermal gradients in the cable cross-section, and the changes of magnetic field and operating current which are typical of a quench transient.