Charge Of The Magnetized Plasma Spiral Theory

In recent years, experiments show that in the plasma loaded high power microwave device may obtain much higher interaction efficiency and output power than the ones absence of plasma. In the theoretic studies, however, in most papers it was assumed that the plasma is immersed in an infinitely strong confining magnetic field. But the confining magnetic field is always finitely strong in reality. In this dissertation, the wave propagation characters in a helix type slow wave structure filled with plasma immersed in finitely strong confining magnetic field is systematically studied. The main contents of this dissertation are as below: 1. By mean of sheath model, the wave dispersion equation in the helix type slow wave structure filled with magnetized plasma is obtained and it is valid for arbitrary azimuthal mode number. At last, through the discussions of this dispersion equation, it is found that many other dispersion equations under special conditions can be derived from this dispersion equation. 2. The dispersion equation is solved numerically for the azimuthally symmetric case. When filled with magnetized plasma, the wave modes change greatly. Hybrid modes are formed when the structure modes are coupled with the modes brought from the magnetized plasma (not only the plasma modes). The relations between the number of the modes involved modes coupling and the plasma densities or the magnetic field intensities are discussed.3. The numerical calculations of field components of the first and the second hybrid modes are given. Because of modes-coupling, the field structure on the same dispersion curve changes greatly with the increase of wave frequency, especially in the first mode which has no zero in the plasma area. 4. By mean of type helix model and Floquet theorem, the dispersion equation and the field components' expressions in the type helix slow wave structure filled with magnetized plasma are obtained.