Luis F. Gomez, Ken R. Ferguson, James P. Cryan, Rico Mayro P. Tanyag, Curtis Jones, Sebastian Schorb, Denis Anielski, Ali Belkacem, Charles Bernando, Rebecca Boll, John Bozek, Sebastian Carron, Gang Chen, Tjark Delmas, Lars Englert, Sascha W. Epp, Benjamin Erk, Lutz Foucar, Robert Hartmann, Alexander Hexemer, Martin Huth, Justin Kwok, Stephen R. Leone, Jonathan H. S. Ma, Filipe R. N. C. Maia, Erik Malmerberg, Stefano Marchesini, Daniel M. Neumark, Billy Poon, James Prell, Daniel Rolles, Benedikt Rudek, Artem Rudenko, Martin Seifrid, Katrin R. Siefermann, Felix P. Sturm, Michele Swiggers, Joachim Ullrich, Fabian Weise, Petrus Zwart, Christoph Bostedt, Andrey F. Vilesov, Oliver Gessner

Lawrence Berkeley National Laboratory

The x-ray diffraction patterns of isolated helium nanodroplets, obtained by femtosecond single shot coherent diffractive imaging (CDI) at the LCLS, offer direct access to sizes and shapes of these superfluid systems. Partly significant deviations from spherical shapes are observed and interpreted as centrifugal distortions of rotating droplets. The spheroidal contours are analyzed in terms of the underlying angular velocity and angular momentum distributions. Mechanisms are discussed to explain the creation and propagation of quantum vorticity in the finite superfluid systems upon their emergence from the directed flow and break-up of bulk liquid helium.