Fast switch with laser initiation

In a low inductance vacuum spark with laser initiation, the switching time dependence on parameters of the initiating laser pulse as well as on the interelectrode gap voltage in a wide range of the values is studied. It is shown that the switching time depends just weakly on the voltage but depends significantly on intensity of the laser pulse, so that at high values of these parameters, the time, in fact, is determined just by the self characteristics of the discharge circuit, i.e. inductance and capacity. This result means that the possible instabilities within the cathode plasma jet are suppressed by means of enhancement of amount of the ablated cathode matter due to the laser irradiation. That permits us to suggest that laser-induced switch with the switching time just of a few nanoseconds can be employed.