The effect of plasma densities on radial profile of the axial electric field for plasma loaded traveling wave tube

A traveling wave tube (TWT) filled with a magnetized plasma enclosed within a loss-free wall in which the gap between the helix and the outer wall is filled with a dielectric material has been considered. By applying the field theory and using the appropriate boundary condition, the axial electric field, the most important parameter in the interaction with electron beam, in traveling wave tube is analyzed numerically. In this work, trend of change for the radial profile of the axial electric field are also analyzed respectively in different plasma densities by numerical computation.