Key Ideas and Main Milestones of Research and Development of Microwave Generators With Virtual Cathode in RFNC-VNIIEF

This article presents a historical review of key ideas and main milestones of the research and development of microwave generators with a virtual cathode in the Russian Federal Nuclear Center—All-Russia Research Institute of Experimental Physics (RFNC-VNIIEF). This article considers a 160-MW efficient pinch vircator, a multielement antenna array producing ~2 GW, which consists of 14 pinch vircators, a 520-MW $C$ -band vircator, and a 4.8-GW $X$ -band hybrid vircator “vircator + traveling-wave tube (TWT)” (both are based on the ironless linear inductive accelerator (LIU), a 100-MW $S$ -band reflex triode with the artificial internal transverse electromagnetic (TEM)-feedback, and a long-pulse ( $3~\mu \text{s}$ ) 220-MW $S$ -band vircator with a plasma anode. All these devices have unique parameters.