Time-resolved cross-beam energy transfer in strongly damped regime on the Laser Mégajoule facility

• DOI: 10.1063/5.0228994
• Publication Date: 2025-01-22T12:51:57Z
• Authors: A. Debayle; P. Loiseau; L. Lecherbourg; P.-E. Masson-Laborde; C. Ruyer; O. Morice; E. Alozy; L. Le-Deroff; T. Caillaud; S. Debesset; C. Hermerel; C. Rousseaux
• Keywords: Beam energy

We report on an experiment performed at the Laser Mégajoule facility to investigate cross-beam energy transfer (CBET) between two kilojoule-nanosecond laser beams propagating through a neo-pentane gas pipe. CBET is diagnosed using time-resolved transmission measurements and x-ray imagers. The obtained calibrated emission conversion gold foil located behind target. Different shots, with without frequency shift, allow control amount of power transferred beams. In particular, we observe that blue-shifted pulse significantly depleted during several nanoseconds when shift data provide quantitative comparisons for benchmarking modeling in our radiative hydrodynamic code. It appears from recovered only no saturation ion acoustic wave amplitude applied linear kinetic modeling. Yet, measured signal not sufficiently accurate discriminate models assuming perfect plane closure those taking into account speckle structure field smoothing by spectral dispersion.