Computer simulation for stability analysis using a one-dimensional model

A simulation program of normal-state propagation was built using a one-dimensional model. The results of the simulations were compared with those of the short-sample tests of the helical coil conductor for the LHD at the National Institute for Fusion Science. This paper deals with the magnetic field profile effect of the recovery currents and the initial temperature profiles of the minimum propagation current. The first purpose of the study is to determine the appropriate length of the short-sample experiment when estimating the properties of conductors in a uniform magnetic field. The second purpose is to examine the behavior of a superconductor when it is heated at several points at the same time instead of at only one point. The results of the simulation shows: (1) when the length of the typical short-sample experiment, which has a helical coil conductor 0.25 m long, is increased by at least four times, the same recovery currents are obtained in a uniform field; and (2) when the total input energy is less than 0.1 J, the minimum propagation current increases as the number of peaks in the initial temperature profile increases. The minimum propagation currents does not depend on the number of peaks when the total input energy is greater than 0.1 J.