Cable guns as a plasma source in a plasma opening switch

The characteristics of a plasma generated by cable plasma guns have been st udied by a laser interferometer, Cable plasma guns are frequently used as a plasma source in plasma opening switches. In our experiments, the plasma s ource consists of eight coaxial cable guns mounted on the outer electrode o f concentric coaxial electrodes. The reproducibility of the gun in subseque nt shots is found to be better than 10%, and the gun-to-gun difference is l ess than 15%. Assuming a symmetry of eight guns, the contour maps of the el ectron plasma density are plotted as function of time, The plasma density b ecomes maximum near the gun nozzle and near the inner coaxial electrode. Th e plasma density is low in the area between the coaxial electrodes during t he early time of the discharge. At a later time, the plasma fills the space between the two guns more uniformly. Still photographs of the plasma lumin osity show a good correspondence with the plasma density plots which were t aken 10 mu s after the discharge initiation. The plasma gun system is desig ned for use in a 400-kA inductive voltage adder with the inductive energy s torage system.