High power microwave radiation from a vircator device: its spatial power distribution and enhancement of E-field by using a coaxial cavity

High power microwave (HPM) radiation greater than 100 MW was generated by virtual cathode oscillator (vircator) method by using the intense electron beam available from the indigenously developed pulse power system KALI-1000. The HPM power in the far field was measured by using a horn antenna and diode detector. The near field power distribution was determined by an array of neon lamps. The emission distribution from the output window was determined by using various apertures of anechoic material on the output window. The HPM also induced a glow at a pressure of 50 Torr in a chamber attached to the output window. The HPM was injected into a cavity in which the E-field was enhanced at its gap and causes discharge at the atmospheric pressure