Coherent diffractive imaging in helium droplets
by Vilesov Andrey (University of Southern California)
at European XFEL ( E1.173 )
Diverse XFEL experiments with helium droplets (D=200-2000 nm) will be discussed. The talk will start with brief introduction of the properties of the helium droplets and techniques for generation of the He droplet beams. Superfluid 4He nanodroplets are ideal model systems to explore quantum hydrodynamics in self-contained, isolated superfluids. X-ray CDI experiments at LCLS enabled attaining the shapes of rotating droplets. Doping of the droplets with heavy atoms, such as Xe, facilitated visualizing quantum vortices and show diversity of vortex arrangements. X-ray scattering from a droplet serves as useful reference for the phase retrieval. Quantum fluid helium droplets exemplify most homogeneous samples well suited for study of the plasma dynamics. Recent IR-pump – x-ray probe experiments revealed unexpected giant shape deformations upon strong ionization. Possible future experiments involve study of quantum turbulence, quantum phase separation in 3He-4He mixed droplets and chemical aggregation at ultra-low temperatures.