Boundary effects in classical dynamics of point charge

Self-action of the classical charge executing the spiral motion along the parallel magnetic and electric fields in the vicinity of the mirror is considered. The radiative correction to Lagrange function determines the cyclotron frequency shift (CFS). The latter shows a quasi-periodic dependence on the external parameters (those being the field strengths and the distance from the mirror). The numerical values of these parameters at which the oscillations of CFS take place, correspond to the conditions of experiment 1 manifested in the vacuum current oscillations under the smooth variation of voltage. The purely classical explanation of that effect is suggested. On the basis of the scalar charge model we also inspect the dependence of the self-energy of the particle on the penetration depth appearing as a parameter (𝛿) in the Robin boundary condition imposed on the self-field of the charge. In the case of circular rotation over the Robin wall the real part of the mass shift shows a resonant behavior. From graphical displays of the exact integral representation of the mass shift, one could observe the resonances despite the dispersion ∼𝛿 of the retardation time between the waves incident on and reflected from the boundary.