Influence of asymmetric injection of laser radiation into capillary waveguides on wake acceleration of electrons possessing various injection energies

Laser wakefield acceleration of electron bunches possessing various initial injection energies in capillary waveguides is studied in the conditions of an asymmetric input of laser radiation into a waveguide (the propagation direction of laser radiation deviates from the capillary axis or the laser spot is not symmetric). The factors determining the critical angle of the laser radiation input into the capillary, within which the wake acceleration of electrons is close to optimal, have been found. It is shown that in acceleration stages where electron energies are high, the requirements to angular concentricity of the capillary axis and laser radiation focusing are substantially weaker due to the relativistic 'weighting' of the electron mass.