Breaking of relativistic electron beam driven wake waves in a cold plasma

Excitation of relativistic electron beam driven Wakefield in a cold, over-dense plasma, is studied using 1D-numerical fluid simulation techniques. For the beam density less or equal to the half of the plasma density, simulation results are found to be in good agreement with the analytical work by Rosenzweig et al. for several plasma periods. For the beam density larger than the half of the plasma density, analytical calculations are presented and compared with simulation results here. At later times, the Wakefield profile shows an irregular behavior and finally breaks via the gradual process of phase mixing. The excited Wakefield profile follows longitudinal Akhiezer-Polovin (AP) mode exactly. The breaking of wake wave is understood in terms of AP wave breaking phenomena and results are compared with the existing theoretical calculations. (author)