Hot Electron Generation by the Two-Plasmon Decay Instability in the Laser-Plasma Interaction at 10.6 μm

Abstract

Hot electron generation in a long-density-scale-length (\ensuremath{\sim}300 \ensuremath{\mu}m) underdense plasma has been studied. For a plasma of maximum electron density of $\frac{1}{4}{n}_{c}$ the hot electron emission is localized in the plane of polarization of the incident C${\mathrm{O}}_{2}$ laser and peaked about 45\ifmmode^\circ\else\textdegree\fi{} with respect to the $\stackrel{\ensuremath{\rightarrow}}{\mathrm{k}}$ vector of the laser beam, in both forward and backward directions. These observations suggest that the hot electrons are generated by the two-plasmon decay instability at quarter-critical density.