Hot Electrons due to Laser Absorption by Ion Acoustic Turbulence

Laser absorption on short-wavelength ion turbulence driven by electron-ion streaming instabilities is considered. Contrary to linear theory, which predicts that the turbulent spectra φ(k) peaks at kλD~0.5, basic plasma experiments find φ(k) peaks at kλD~0.04-0.2 which, this Letter shows by theory and simulation, heats most strongly at densities (0.7-1.2)nc and produces hot electrons ~(5-70)Tₑ (depending on the density) which are another source of preheat that may reduce the compression and yield of laser fusion targets.