A coaxially loaded helical slow-wave structure for TWTs

In this paper, we present the analysis of a new type of helical slow-wave structure with a coaxial insertion for a possible employment in TWTs in conventional slow-wave regime. By making use of the field theory and equivalent circuit analysis approaches, the dispersion relation and the equivalent circuit parameters, namely, capacitance per unit length, inductance per unit length, and characteristic impedance of the cold interaction structure are deduced.