Ultra-Fast X-Ray Thomson Scattering Measurements of Insulator-Metal Transition in Shock-Compressed Matter.

摘要

Spectrally resolved scattering of ultra-short pulse laser-generated K-alpha x rays has been applied to measure the heating and compression of shocked solid-density lithium hydride. Two shocks launched by a nanosecond laser pulse coalesce yielding pressures of 400 gigapascals. The evolution of the intensity of the elastic (Rayleigh) scattering component indicates rapid heating to temperatures of 25,000 K on a 100 ps time scale. At shock coalescence, the scattering spectra show the collective plasmon oscillations indicating the transition to the dense metallic plasma state. The plasmon frequency determines the material compression, which is found to be a factor of three thereby reaching conditions in the laboratory important for studying astrophysics phenomena.