Grid control over high currents in a cesium discharge with a cathode spot

We report on the results of investigation of a plasma switch with complete grid control in a discharge with a cathode spot on the liquid-metal cesium cathode without grid diaphragming. The retention of the working area of the grid relative to the anode area leads to an order-of-magnitude increase in the switching anode current (up to 20 A/cm$^2$ over the anode area) and a substantial (up to 100 V and higher) increase in the switching voltages. The use of the cathode jet makes it possible to reduce the working pressures of cesium vapor (down to 10$^{-3}$ Torr). We discuss the results of analysis of peculiarities of grid discharge quenching in such a switch, which make it possible to determine possible reasons for limitation of the working parameters of the switch and the ways of their further increase.