Collapsing Solid Potassium Liner Driven by Axial Magnetic Field

抄録

An experiment was undertaken on the θ-pinch collapse of a solid potassium liner in a temperature range of 1057°C. The liner was 47mm long and 34mm thick with an outside diameter of 66mm. The radial motion of the collapsing liner was analyzed by visco-plastic model. In the above range of temperature, assuming the potassium to behave as a Bingham fluid, the kinematic elongational viscosity and the yield stress of solid potas-sium were found to be roughly 24m²/s and bar, respectively, based on the experi-mental data obtained from the collapsed liner. The perturbed motion due to the Rayleigh-Taylor instability was also analyzed with account taken of the effect of viscosity. The kinematic shear viscosity obtained from the elongational viscosity is known to be of the order of 1m²/s. The evidence would indicate that this shear viscosity is so large as to exert an inhibitive effect on the perturbations of higher mode (m ?? 10) under the present experimental conditions.