Доповідач
Опис
Generation of wakefield by a single relativistic electron bunch in a plasma-dielectric accelerating structure has been studied both analytically and numerically. The structure represents a dielectric-loaded cylindrical metal waveguide, which has partially plasma-filled channel (hollow plasma channel) to transport charged particles. Assuming the linear regime of excitation, analytical expressions have been derived for the longitudinal and radial wakefields generated by a finite-size electron bunch. Axial profiles of wakefield component amplitudes have been studied, and their mode and spectrum analyses have been performed. An analysis of a dispersion of the dielectric waveguide with hollow plasma channel demonstrated the presence of two surface eigenwaves, which are absent in corresponding dielectric-loaded waveguide without plasma filling. Numerical studies showed the possibility of acceleration of both electron and positron test bunches with their simultaneous radial focusing. Fourier analysis of a transverse wakefield demonstrated that a main contribution to its amplitude belongs to a backward plasma surface eigenwave. Furthermore, the electron bunch-driven wakefield excitation has been PIC-simulated numerically for the quasi-linear regime. The comparative analysis of the data resulting from analytical studies and the ones obtained by numerical simulation has demonstrated qualitative agreement between the results.
