Analysis on the propagation characteristics of the EM wave in the nonuniform magnetized plasma sheath
A novel FDTD method, Shift-Operator Finite Difference Time-Domain (SO-FDTD) is promoted. Propagator matrix method (PMM) is successfully utilized to study the propagation characteristics of EM waves in the nonuniform magnetized plasma sheath model of blunt cone. The results of the two methods are compared and both of results indicate that the external magnetic field changes propagation characteristics of EM waves in plasma, broadens the transmission bandwidth and improves the transmissivity of EM waves, which can be perfectly applied in re-entry communications.
Simulation of the influence high-frequency (2 MHz) capacitive gas discharge and magnetic field on the plasma sheath near a surface in hypersonic gas flow
The plasma sheath near the surface of a hypersonic aircraft formed under associative ionization behind the shock front shields the transmission and reception of radio signals. Using two-dimensional kinetic particle-in-cell simulations, we consider the change in plasma-sheath parameters near a flat surface in a hypersonic flow under the action of electrical and magnetic fields. The combined action of a high-frequency 2-MHz capacitive discharge, a constant voltage, and a magnetic field on the plasma sheath allows the local electron density to be reduced manyfold.
Microwave source with enhanced radiation power based on orbitron MASERs
We have proposed the design of high power microwave source in a vacuum tube based on the theory of negative mass instability. The proposed source does not operate based on a slow-wave structure but instead makes use of accelerated charged particles. In our structure, an electron emitter injects the charged particles into to the cavity. Emitted particles move around the anode, which leads to electron acceleration and emission of electromagnetic waves with a specific frequency. In this paper, we have enhanced the output power and frequency of microwave source by variation of particles initial energy and the number of anodes incorporating their specific arrangement and applied voltages. Working at room temperature, compactness, wide bandwidth, and tunability of output frequency are among the advantages of the proposed source.