Crossed beam energy transfer between optically smoothed laser beams in inhomogeneous plasmas - Archive ouverte HAL Access content directly
Journal Articles Philosophical Transactions of the Royal Society A: Mathematical, Physical and Engineering Sciences Year : 2020

Crossed beam energy transfer between optically smoothed laser beams in inhomogeneous plasmas

Abstract

Crossed beam energy transfer, CBET, in high-intensity laser plasma interaction is investigated for the case of optically smoothed laser beams. In the two approaches to laser-driven inertial confinement fusion (ICF) experiments, the direct-drive and the indirect-drive, CBET is of great importance because it governs the coupling of laser energy to the plasma. We use the two-dimensional wave-coupling code Harmony to simulate the transfer between two laser beams with speckle structure that overlap in a plasma with an inhomogeneous flow profile. We compare the CBET dynamics for laser beams with spatial incoherence and with spatio-temporal incoherence; in particular we apply the smoothing techniques using random phase plates (RPP) and smoothing by spectral dispersion (SSD), respectively. It is found that for laser beams (wave length λ0) with intensities (IL) above IL ∼ 2 × 10 15 W cm −2 (λ0/0.35µm) −2 (Te/keV), both the so-called plasma-induced smoothing as well as self-focusing in intense laser speckles induce temporal incoherence; the latter affects the CBET and the angular distribution of the light transmitted behind the zone of beam overlap. For RPP-smoothed incident beams, the resulting band width of the transmitted light can already be of the same order as the effective band width of the SSD available at major laser facilities. We examine the conditions when spatio-temporal smoothing techniques become efficient for CBET.
Fichier principal
Vignette du fichier
CBET-SSD_accepted_v2.pdf (3.83 Mo) Télécharger le fichier
Origin : Files produced by the author(s)
Loading...

Dates and versions

hal-02880936 , version 1 (25-06-2020)
hal-02880936 , version 2 (28-07-2020)

Identifiers

Cite

Stefan Hüller, Gaurav Raj, Mufei Luo, Wojciech Rozmus, Denis Pesme. Crossed beam energy transfer between optically smoothed laser beams in inhomogeneous plasmas. Philosophical Transactions of the Royal Society A: Mathematical, Physical and Engineering Sciences, 2020, ‘Prospects for high gain inertial fusion energy’, ⟨10.1098/rsta.2020.0038⟩. ⟨hal-02880936v2⟩
166 View
109 Download

Altmetric

Share

Gmail Facebook X LinkedIn More