Control and propulsion of an atmospheric pressure plasma ring

A new approach for the electromagnetic control and propulsion of a current carrying electric arc plasma ring is described. The essence of the approach is to form and manipulate the arc plasma outside rather than inside an electromagnetic field (B-field) producing coil so that pulsed plasma thrusts can be produced in a choice of different directions. The interaction of the electric arc, formed in atmospheric pressure air, with such B-field has been investigated. It has been shown that a stable azimuthal plasma ring can rapidly be produced by the simple process of separating two annular contacts. Pulsed plasma propulsion is obtained when the arc plasma, and B-field sustaining current is automatically reduced to zero, whereby the constraining electromagnetic forces are removed and, as a consequence, the resulting plasma ring radially expands outwards. Several different measurement techniques have been deployed for investigating the behavior of the plasma ring. These include electrical probing, B-field probing, and high-speed plus video photography. Experimental results are shown to be in good agreement with theoretical estimates based upon a Sedov's self-similar model.