Amplitude enhancement of plasma wakefield by interaction of relativistic Gaussian electron beam with inhomogeneous magnetized plasma

摘要

The nonlinear dynamics of plasma wakefield in the interaction between a relativistic Gaussian electron beam and an inhomogeneous plasma is theoretically studied. The effects of physical parameters, such as the length of the driving electron bunch, the initial plasma density profile, and the static magnetic field strength on the evolution of the plasma wakefield amplitude, are discussed. It is found that the amplitudes of both the longitudinal electric field and the perturbed electron density behind the beam are larger in an inhomogeneous plasma than in a homogeneous plasma. Moreover, in a medium with periodical density variations, the change in the plasma wakefield amplitude is periodical and so the perturbed density behind the beam. It is also found that the plasma wakefield is maximum for a definite length of the drive bunch along the propagation direction. Thus, for a special system of plasmas and drive bunches, it is possible to transfer the maximum energy from a driving electron beam to the particles in the witness bunch and accelerate them to higher energies.