Experiments on Magnetoelastic Buckling in a Superconducting Torus

Abstract

A 16 coil superconducting torus is used to study magnetoelastic instabilities in a set of current carrying elastic rings. The torus is a 1/75th model of a proposed magnetic fusion reactor. Up to 130 KA-turns were placed in the 30-cm-dia torus. Three different lateral constraint conditions on the elastic magnets are discussed. Both dynamic and static methods are used to determine the critical buckling currents. The coils are observed to pair up during buckling. A series of snap-type instabilities were observed near the critical buckling current for the lowest mode. A fair to good comparison between experimental and theoretical values of the buckling currents for all three modes is obtained when tension stiffening corrections are included.