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Intentional Destructive Electromagnetic Impacts
Published in Vladimir Gurevich, Cyber and Electromagnetic Threats in Modern Relay Protection, 2017
Vircators can produce very powerful individual energy impulses, which are structurally simple, not large in terms of their size, durable, and capable of working in a relatively wide band of microwave range frequencies. The fundamental idea behind a vircator is to accelerate a powerful flow of electrons by a grid anode. This powerful flow of electrons initially leaves the cathode (metal cylinder-shaped rod, several centimeters in diameter [Figure 3.5]) as affected by high-voltage impulse (hundreds of kilovolts), which provides the emission of electrons’ explosive behavior. Significant number of electrons goes through the grid anode creating a charge cloud behind the anode. Under specific conditions, this charge cloud will be oscillating in the area of anode (Figure 3.6).
Klystrons and related devices
Published in R A Cairns, A D R Phelps, P Osborne, Generation and Application of High Power Microwaves, 2020
In the vircator, the current, and then the voltage depression, are so high that the electrons are not only stopped—creating a “virtual cathode”—but some also come back toward the real cathode giving rise to a strong microwave oscillation. The vircator is an oscillator with just one resonant cavity.
Experimental investigation and design of sectoral waveguide TM01 to TE11 mode converter
Published in Journal of Microwave Power and Electromagnetic Energy, 2019
Vikram Kumar, Smrity Dwivedi, P. K. Jain
In microwave systems, we often require the conversion of the RF output mode of a device into the desired mode, to feed the next device. A mode converter should be compact in structure and possess high conversion efficiency. Sectoral waveguide (SWG) mode converter is an all-metal structure that can be used in high-power microwave (HPM) systems as such converters can handle heat transfer and sustain at high temperatures. These mode converters are used with the HPM sources for various applications including strategic high-power radiators, space beam rockets, and solar-power transmission through space, as well as to enhance capabilities of advanced radar and communication systems and for rebuilding the ozone layer (Benford et al. 2007). Some HPM sources e. g., a magnetic-insulated transmission-line oscillator (MILO), a relativistic backward oscillator (RBWO), a relativistic-klystron oscillator (RKO) and virtual cathode oscillator (VIRCATOR) radiate RF energy in azimuthally symmetrical modes such as TEM or TM01.