Journal of Theoretical and Applied Physics (JTAP) Plasma effect in tape helix traveling-wave tube Volume 8 (2014) Issue 2, May and June 2014 2023 11 17 Plasma effect in tape helix traveling-wave tube 10.1007/s40094-014-0125-9 EN Journal Article 2023 11 17 AbstractA linearized relativistic field theory of a plasma-loaded helix traveling-wave tube is presented for a configuration where a solid electron beam propagate through a sheath helix enclosed within a loss-free wall in which the gap between the helix and the outer wall is filled with a dielectric. Numerical study of the effect of plasma density on the phase velocity and growth rate has been done. Numerical results show that the plasma have different behaviors in different density limits.