Analysis of the Structure of the Roughness Profile of the mm-Band Gyrotron Resonator and Comparison With Theoretical Models

Determining the ohmic$Q$-factor of gyrotron resonators in the millimeter wavelength range requires accounting for the surface roughness, which is incorporated via the effective conductivity coefficient${k}_{\textit {skin}}$. Although most calculation models for gyrotrons assume this value to be 2, its precise determination for a specific surface remains a relevant task. In this work, a theoretical approach previously developed for a model of the roughness profiles is applied to a real resonator. The surface profile was measured, the obtained data were processed, and the effective conductivity, along with the corresponding${k}_{\textit {skin}}$coefficient, was determined. The results obtained can determine both the main parameters of the roughness profile and the limits of applicability of the theoretical model used.