Ultrafast Thermal Melting in Nonequilihrium Warm Dense Copper

The ultrafast dynamics of the loss of crystalline periodicity is investigated in femtosecond laser heated warm dense copper, by the original use of x-ray absorption near-edge specific structures just above the L3 edge. The characteristic time is observed near 1 ps, for specific energy density ranging from 1 to 5 MJ/kg, using ps-resolution x-ray absorption spectroscopy. The overall experimental data are well reproduced with two-temperature hydrodynamic simulations, supporting a thermal phase transition.

Automated summary

The ultrafast dynamics of the loss of crystalline periodicity in femtosecond laser heated warm dense copper was studied using x-ray absorption near-edge structures above the L3 edge. A characteristic time of approximately 1 ps was observed for energy densities ranging from 1 to 5 MJ/kg, with the experimental data well reproduced by two-temperature hydrodynamic simulations, indicating a thermal phase transition.