Stabilization and correction of aberrated laser beams via plasma channelling.

High-power laser applications, and especially laser wakefield acceleration, continue to draw attention through various research topics, and may bring many industrial applications based on compact accelerators, from ultrafast imaging to cancer therapy. However, one main step towards this is the arch issue of stability. Indeed, the interaction of a complex, aberrated laser beam with plasma involves a lot of physical phenomena and non-linear effects, such as self-focusing and filamentation.

Modular supersonic nozzle for the stable laser-driven electron acceleration.

The sharp density down-ramp injection (shock injection) mechanism produces the quasi-monoenergetic electron beam with a bunch duration of tens of femtoseconds via laser wakefield acceleration. The stability of the accelerated electron beam strongly depends on the stability of the laser beam and the shock structure produced by the supersonic gas nozzle. In this paper, we report the study of a newly designed modular supersonic nozzle with a flexible stilling chamber and a converging-diverging structure.

Coupling Effects in Multistage Laser Wake-field Acceleration of Electrons.

Staging laser wake-field acceleration is considered to be a necessary technique for developing full-optical jitter-free high energy electron accelerators. Splitting of the acceleration length into several technical parts and with independent laser drivers allows not only the generation of stable, reproducible acceleration fields but also overcoming the dephasing length while maintaining an overall high acceleration gradient and a compact footprint. Temporal and spatial coupling of pre-accelerated electron bunches for their injection in the acceleration phase of a successive laser pulse wake field is the key part of the staging laser-driven acceleration.

Using X-ray spectroscopy of relativistic laser plasma interaction to reveal parametric decay instabilities: a modeling tool for astrophysics.

By analyzing profiles of experimental x-ray spectral lines of Si XIV and Al XIII, we found that both Langmuir and ion acoustic waves developed in plasmas produced via irradiation of thin Si foils by relativistic laser pulses (intensities ~10 W/cm). We prove that these waves are due to the parametric decay instability (PDI). This is the first time that the PDI-induced ion acoustic turbulence was discovered by the x-ray spectroscopy in laser-produced plasmas.