Ion wave breaking acceleration: Study of breaking dynamics and finite trapping

Laser driven ion wave breaking acceleration (IWBA) in a plasma wake field is investigated with the help of particle-in-cell (PIC) simulations and theoretical methods. IWBA operates in relativistic self-transparent plasma for laser intensities in the range of 10(20) - 10(23) W/cm(2). When propagating a laser pulse in a transparent plasma, a co-moving cold ion wave is produced due to ion oscillation. When driven strongly, the oscillation is nonlinear and eventually breaks. Then a fraction of ions is self-injected into the laser driven wake. The wake field is square-wave like and sensitive to the injected ions. After an injection, the wake weakens and then there is no further injection. This leads to a superior ion pulse with peaked energy spectra; in particular in realistic three-dimensional (3D) geometry, the injection occurs localized close to the laser axis producing highly directed bunches.