Jincheol B. Kim

Characteristics of pulse compression in laser pulse amplification by stimulated Raman backscattering

The characteristics of pulse compression during the laser pulse amplification using two counter-propagating laser pulses have been investigated using a one-dimensional fluid model of stimulated Raman backscattering. The front and the rear pulse widths of the amplified laser pulse are examined in terms of the initial pump and seed amplitude, and the ratio of the electron plasma frequency to the laser frequency. The pulse widths have a common scaling behaviour in time over the considered parameter regime. The scaling exponents of the pulse widths during broadening and compression are all the same as 1.0. The pulse compression scaling shows a reciprocal behaviour to the peak energy growth.

Effect of preplasmas on high-energy ion generation by an intense laser pulse irradiated on overdense plasmas

High-energy ion generation from the interaction of an ultrashort intense laser pulse with an overdense plasma slab is studied with fully electromagnetic and relativistic particle-in-cell simulation. With a properly designed underdense preplasma, we observed that the forward ion acceleration from the front surface can be enhanced. The momentum distribution functions of the accelerated ions are investigated with respect to the laser pulse intensity and the preplasma profile.