Abstract
We report on the dynamics of ultrafast heating in cryogenic hydrogen initiated by a , 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 . 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.
- Received 29 October 2013
DOI:https://doi.org/10.1103/PhysRevLett.112.105002
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