Search academic texts

Information × Registration Number 0219U102273, 0119U102724 , R & D reports Title Generation of intense terahertz electromagnetic fields by electron beams and laser pulses popup.stage_title Head Kniaziev Roman R., Кандидат фізико-математичних наук Registration Date 26-12-2019 Organization National Science Center "Kharkiv Institute of Physics and Technology" popup.description2 An analytical study of a wakefield excitation of the THz frequency range by the relativistic electron bunches in a plasma-dielectric waveguide is carried out. A structure as a cylindrical waveguide, which is partially filled with a dielectric along the axis of which is a vacuum channel partially filled with a homogeneous plasma column was chosen. A dispersion equation that relates the frequency of eigenwaves with a wave number, which determines the phase and group velocities of the waves, is obtained. The analytical expressions for the bunch-excited field components in the region of plasma column, vacuum, and dielectric are constructed. The studies of a resonance electromagnetic fields excitation in plasma of the THz frequency range by resonant and non-resonant sequences of relativistic electron bunches (a repetition bunch frequency does not coincide with the plasma frequency) by numerical simulation have been performed. The results of the resonant asymptotics of a wave excitation in a plasma by a non-resonant sequence of relativistic electron bunches (an excitation of a wakefield with the maximum growth rate when the interaction of the excited wakefield with the electron beam in the acceleration phases is insignificant) are obtained. The numerical simulations of an electron beam acceleration process using two-sided dielectric chip structures and single-comb dielectric structures were performed. Two important cases of an accelerating field excitation by a laser pulse are considered, namely: (1) a laser irradiates the structure from the substrate, (2) a laser irradiates the structure from the periodic structure and electron flux. In order to determine an optimum profile of structures, rectangular, triangular, sinusoidal, and cylindrical profiles were considered that can be relatively easily implemented in the experiment. Product Description popup.authors Vasyliev Andrii V. Levchuk Iryna P. popup.nrat_date 2020-04-02 Close