Experiments on Buckling and Vibration of Superconducting Coils

Abstract

The decrease in lateral stiffness with increase in current and subsequent buckling of a flexible superconducting coil in a three coil partial torus is reported. The instability was observed for both clamped and clamped-pinned constraints on circular coils. Tests on the in-plane stability show an increase in stiffness with current in contrast with the out of plane or lateral buckling behavior. Along with the decrease in lateral natural frequencies of the coils, a significant increase in damping was observed. The critical buckling current was found to be in good agreement with theoretical calculations based on the authors’ previous work.