The Linear Theory Of Plasma Loaded Disk-loaded Waveguide Slow-wave System

Seeking for some new slow-wave structures with broader bandwidth and higher power capacity is the constant goal. Worldwide scholars have made a great effort in this field since 50's of twenty century. In recent years, especially, it has been developing rapidly due to excellent prospects of military and commercial application. Disk-loaded waveguide is a kind of slow-wave structure with long history. It is developed by putting disk in cylindered wave-guide periodically. Disk-loaded waveguide is classified into two types. One is with central hollow and the other is with edge hollow. Disk-loaded waveguide with central hollow is applied widely in linear accelerator. In recent years, disk-loaded waveguide is also applied in the high power wave tube domain because of it has simple structure, big size, good refrigerant performance and good stability. It is researched and discovered that filling plasma into microwave instrument may increase it's output power and interaction efficiency and improve transmission quantity of electronic beam.First, based on disk-loaded waveguide theory expression equation of every field after filled in plasma is analysed strictly. Dispersive equation and coupling impedance equation are derived using borderline condition and function quadrature. The geometric parameter's effect on dispersive equation and couple impedance is dicussed in detail. The result is plasma filled in disk-loaded waveguide may improve property of wave conduct.Second, the beam and wave interactive linear theory of filled plasma in disk-loaded waveguide is studed. Concerning solid electronic beam, field equations of slow wave in every field are got. Then using borderline condition and strictly field match method , "heat" dispersive equation considering special electric charge effect is derived. Concerning high power line wave tube, considering the theory of relativity effect of electronic beam we calculate "heat" dispersive equation and get the relativity between filling plasma in disk-loaded waveguide geometric parameters, electric beam parameters and small-signal gain.