Arc Phenomena and Gasdynamic Effects due to Interaction of Shock Waves with Magnetic Fields

The arc phenomena occurring on interaction of shock-heated plasma with a magnetic field were studied in order to achieve an approximately uniform current distribution in a certain volume using a number of small electrodes. This is necessary for producing plane gasdynamical effects such as reflected shocks and one-dimensional flow behind them in order to compare experimental results with theory. The current amplitude depends on the surface area and the number of electrodes. It is governed by the complex boundary conditions in the plasma-to-electrode transition, which consists of narrow current channels leading to arc spots. Streak photographs show that the flow is slowed down, and reflected fronts are observed which can be interpreted as shock fronts taking relaxation effects into account.