A novel approach to form second virtual cathode by installing a floating zone plate inside the drift tube

Abstract In this study, a new mechanism is proposed to develop a second virtual cathode (VC2). An axial vircator was simulated by adding a floating zone plate (ZP) inside the drift tube, which is designed at the dominant frequency of 3.42 GHz. The obtained results indicated that the floating ZP contributes to form a VC2 by using the drifting electrons as wall charges. The charge of a newborn VC2 interacts with electromagnetic (EM) waves generated from conventional VC1 to amplify its magnitude and the output power increases from 150 MW to 652 MW. Theoretical analysis indicates that the optimum synergy effects of these two VCs (VC1 and VC2) occur when the distance between them is the wavelength of EM waves, which agree well with simulation data. These results may demonstrate an important breakthrough in vircator research, introducing a new approach to use the drifting electrons to form a VC2 for power amplification.