The applicability of snowplough theory for the description of the motion of plasmas in electromagnetic shock-tubes is studied. The effects of various means of mass pickup and of various wave forms of driving current are included in the analysis. A comparison of the theoretical predictions with experimental results reveals the importance of materials eroded from the components of the driver. Snowplough theory is also found to predict the observed motion of the decelerating plasma fairly accurately when the initial pressure in the shock tube is low and the mass of the driver gases large. The proposed model for the decelerating plasma is suggestive of one reason, a large mass of driver gases present, why various workers have obtained different values for β in the often-quoted relation [Formula: see text].
Experimental studies on conical electromagnetic shock tubes
