Field analysis for a configuration of sheath helix in the presence of a metallic rod

چکیده مقاله

The field analysis for a configuration of sheath helix in the presence of a coaxial metallic rod and strongly magnetized plasma under two conditions, i.e. , is presented. The electromagnetic field components in the configuration are obtained. The effects of a coaxial metallic rod in a plasma-loaded sheath helix traveling wave tube by means of a theoretical approach, in which infinite magnetic field has been adopted to represent the plasma response, is investigated. We presume that for the finite beam term, the mode structures remain unmodified and only the eigenfrequencies are modified. Therefore, the growth rate of slow electromagnetic waves and so their dispersion relation is calculated. Effects of frequency and plasma frequency on the growth rate are investigated. The obtained results are graphically presented.