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 $\varphi \mathrm{}\left(k\right)\mathrm{}$ peaks at $k{\lambda }_{\mathrm{D}}\sim 0.5$, basic plasma experiments find $\varphi \mathrm{}\left(k\right)\mathrm{}$ peaks at $k{\lambda }_{\mathrm{D}}\sim 0.04-0.2$ which, this Letter shows by theory and simulation, heats most strongly at densities $\mathrm{}(0.7-1.2)\mathrm{}{n}_c$ and produces hot electrons $\sim \mathrm{}(5-70)\mathrm{}{T}_e$ (depending on the density) which are another source of preheat that may reduce the compression and yield of laser fusion targets.