Flux-limited nonequilibrium electron energy transport in warm dense gold

Phys Rev Lett. 2012 Apr 20;108(16):165001. doi: 10.1103/PhysRevLett.108.165001. Epub 2012 Apr 16.

Abstract

An abrupt change in energy transport has been observed in femtosecond laser heated gold when the absorbed laser flux exceeds ~7×10(12) W/cm(2). Below this value, the absorbed flux is carried by ballistic motion of nonthermal electrons produced in interband excitation. Above this value energy transport appears to include ballistic transport by nonthermal electrons and heat diffusion by thermalized hot electrons. The ballistic component is limited to a flux of ~7×10(12) W/cm(2). This offers a unique benchmark for comparison with theory on nonequilibrium electron transport.