New Methods for Generating Cylindrical Imploding Shocks

Abstract

The imploding shock generated by the explosion of explosives has been investigated to produce extreme conditions. The conventional method is the simultaneous explosion of an annular explosive shell which is initiated by the application of a giant pulse of current to fine copper wires. Two new methods of shock focusing on a small area are conceived and tested. One is the use of a cylindrical disk plate (the flyer disk method) and another is the explosion of a log-spirally shaped explosive sheet (the log-spiral method). The flyer disk method has channel effects that accelerate the imploding shock faster than the detonation speed of the explosive. The experimental results showed that the imploding shock speed is nearly double as in the conventional method. In the log-spiral method, if the propagation speed of the shock generated by the explosion is nearly constant, then it focuses around the pole of the log-spiral. High speed framing camera photographs show a good result when the appropriate log-spiral form is chosen.