Effect of experimental laser imperfections on laser wakefield acceleration and betatron source

J Ferri (1, 2) , X Davoine (1) , S Fourmaux (3) , J C Kieffer (3) , Sébastien Corde (2) , Kim Ta Phuoc (2) , Agustin Lifschitz (2)

1 DAM/DIF - DAM Île-de-France
2 LOA - Laboratoire d'optique appliquée
3 EMT-INRS - Énergie Matériaux Télécommunications - INRS

Laser pulses in current ultra-short TW systems are far from being ideal Gaussian beams. The influence of the presence of non-Gaussian features of the laser pulse is investigated here from experiments and 3D Particle-in-Cell simulations. Both the experimental intensity distribution and wavefront are used as input in the simulations. It is shown that a quantitative agreement between experimental data and simulations requires to use realistic pulse features. Moreover, some trends found in the experiments, such as the growing of the X-ray signal with the plasma length, can only be retrieved in simulations with realistic pulses. The performances on the electron acceleration and the synchrotron X-ray emission are strongly degraded by these non-Gaussian features, even keeping constant the total laser energy. A drop on the X-ray photon number by one order of magnitude was found. This clearly put forward the limitation of using a Gaussian beam in the simulations.

Domains: Plasma Physics [physics.plasm-ph]

J Ferri, X Davoine, S Fourmaux, J C Kieffer, Sébastien Corde, et al.. Effect of experimental laser imperfections on laser wakefield acceleration and betatron source. Scientific Reports, 2016, 6, pp.27846. ⟨10.1038/srep27846⟩. ⟨hal-01337403⟩