A liquid conductor model of instabilities in a pinched discharge

In order to study the instubilities of a pinched gas discharge, a liquid scale model of the discharge column is constructed. The model consists of a freely fulling vertical, cylindrical stream of mercury. The stream is carrying a direct current, and its stability to electromagnetic disturbances is studied. Different types of instability are found in cases with and without a longitudinal magnetic field. A 3000 frames per second high speed camera is used, and the films taken show the growth of sausage'' and lateral instabilities. A possible analogy with gas discharge pinch intstabilities is discussed. (auth)