Effect of Transition Radiation and Dispersion Spreading at Achievement of a Large Transformer Ratio of Driver-Bunch Energy Into Wakefield in a Dielectric Resonator Accelerator

Abstract

Possibility of increase of transformer ratio TR in the case of the profiled sequence of bunches at their injection in a two-beam electron-positron dielectric-resonator collider is considered. Unlike considered earlier the waveguide case, for which TR is equal to the doubled number of bunches of sequence which provide a contribution to the total wakefield, and which is limited by the effect of the group velocity, in a resonator this limitation is absent. For derivation in the case of resonator of TR, proportional to the number of bunches, as well as in the waveguide, the ratio of bunch charges is selected to be equal 1:3:5: … , lengths of bunches, equal to the half of wavelength, interval between bunches is multiple to the wavelength. The effect of transition radiation and dispersion spreading on the transformer ratio is studied by numerical simulation.

Homogeneous Focusing Field for Short Relativistic Electron Bunches in Plasma

“…As plasma in experiment is inhomogeneous and nonstationary and properties of wakefield changes at increase of its amplitude it is difficult to excite wakefield resonantly by a long sequence of electron bunches (see [1,2]), to focus sequence (see [3][4][5][6][7][8]), to prepare sequence from long beam (see [9][10][11]) and to provide large transformer ratio (see [12][13][14][15][16][17][18]). Providing a large transformer ratio is also being studied in dielectric accelerators (see [19][20][21][22][23][24]). In [2] the mechanism has been found and in [25][26][27][28][29] investigated of resonant plasma wakefield excitation by a nonresonant sequence of short electron bunches.…”

Transformer Ratio Dependence on Bunch Length at Non-Linear Wakefield Excitation in Plasma by Electron Bunch With Gaussian Charge Distribution

“…As plasma in experiment is inhomogeneous and nonstationary and properties of wakefield changes at increase of its amplitude it is difficult to excite wakefield resonantly by a long sequence of electron bunches (see [3,4]), to focus sequence (see [5][6][7][8][9][10]), to prepare sequence from long beam (see [11][12][13]) and to provide large transformer ratio (see [14][15][16][17][18][19][20]). Providing a large transformer ratio is also being studied in dielectric accelerators (see [21][22][23][24][25][26]). In [4] the mechanism has been found and in [27][28][29][30][31] investigated of resonant plasma wakefield excitation by a nonresonant sequence of short electron bunches.…”