Resolving ultrafast heating of dense cryogenic hydrogen.
Phys Rev Lett
; 112(10): 105002, 2014 Mar 14.
Article
en En
| MEDLINE
| ID: mdl-24679300
ABSTRACT
We report on the dynamics of ultrafast heating in cryogenic hydrogen initiated by a â²300 fs, 92 eV free electron laser x-ray burst. The rise of the x-ray scattering amplitude from a second x-ray pulse probes the transition from dense cryogenic molecular hydrogen to a nearly uncorrelated plasmalike structure, indicating an electron-ion equilibration time of â¼0.9 ps. The rise time agrees with radiation hydrodynamics simulations based on a conductivity model for partially ionized plasma that is validated by two-temperature density-functional theory.