Ultrafast Fluid Dynamics and Cavitation Studies with X-ray Lasers
March 1, 2017
Claudiu Stan, Stanford PULSE Institute, SLAC National Accelerator Facility
Wednesday, March 1, 2017 at 1:00 PM
in Room 2403 at 701 West Grace Street (Laurel St. Entrance)
The extreme intensity of X-ray lasers, combined with their angstrom wavelengths and femtosecond pulse durations, enable scientists to observe the instantaneous structure of matter with atomic scale resolution. Another promising but less explored application of X-ray lasers is to drive rapid processes and transformations in materials. I will present our investigations on the dynamics of X-ray laser ablation in liquid microjets and microdrops. We found that the phenomena induced by X-ray lasers have unique features compared to the case of optical ablation. In particular, the X-ray laser produced highly symmetric liquid explosions, and we were able to model their basic fluid dynamics. In a following study, we used shock waves produced by X-ray lasers to induce and study cavitation in water on a few-nanosecond time scale. At these time scales, cavitation occurred in extremely metastable conditions, characterized by negative pressures that exceed significantly those achieved previously in bulk water. Our cavitation experiment enables the study of water under highly metastable conditions, and provides an avenue to understand the nucleation of cavitation in water. More generally, X-ray laser ablation has the potential to control with (sub)nanosecond precision the nanoscale dynamics of pressure-driven processes such as nucleation, phase transitions, and mechanical failure.