Stability analysis of superconducting magnet: an approach to quantification of energy of disturbance caused by conductor motion

One of the most intricate disturbances causing quenches in high current-density superconducting magnets is an abrupt conductor motion. There have been few papers investigating the disturbance energy of the conductor motion and it is generally understood that its quantification is very difficult. In this paper a model to quantify the disturbance energy due to conductor motion is proposed. The model relates the disturbance energy to mechanical properties of a conductor, electromagnetic force and winding structure. The stability of a superconducting composite conductor subject to an abrupt conductor motion is analysed based on the proposed model. It is pointed out that the stability of the conductor is improved by decreasing distance between spacers placed between the conductors. However, it is also pointed out that there is a limit to the improvement of the stability by decreasing the spacer distance, because of limited accuracies of the conductor and spacer dimensions.