AAAR 33rd Annual Conference
October 20 - October 24, 2014
Rosen Shingle Creek
Orlando, Florida, USA
Abstract View
High Intensity X-ray Scattering of Nanosized Ice Particles Formed in a Supersonic Nozzle
ANDREW AMAYA, Viraj Modak, Harshad Pathak, Michael Bogan, Hartawan Laksmono, Claudiu Stan, Duane Loh, Raymond Sierra, Anders Nilsson, Jonas Sellburg, Trevor McQueen, Sebastien Boutet, Garth Williams, Marc Messerschmidt, Barbara Wyslouzil, The Ohio State University
Abstract Number: 493 Working Group: Aerosol Physics
Abstract Supersonic nozzles with cooling rates of about 10$^5 K/s are able to probe both vapor-liquid and liquid-solid phase transitions at extreme nucleation rates of up to 3 x 10$^(17) cm$^(-3)s$^(-1) for vapor-liquid and up to 6.6 x 10$^(22) cm$^(-3)s$^(-1) for liquid-solid. The ice formed by the liquid-solid phase transition in this process is thought to be cubic. To examine the structure of the nanometer sized ice crystals, x-ray diffraction experiments are needed with a range of scattering vectors, q, between 1.0 A$^(-1) and 3.5 A$^(-1). These experiments should be possible using either the Free Electron Laser at the LCLS (CXI beamline) or the conventional synchrotron radiation at the APS (BESSRC 12-ID). The advantage of using CXI is that the high intensity of the beam can potentially provide high resolution imaging of single isolated particles, and using the LCLS to probe aerosol produced in a supersonic nozzle has never been attempted before. Using the Free Electron Laser at the LCLS in the supersonic nozzle generated a 2-D x-ray scattering pattern with concentric rings located at q values of 1.74 A$^(-1), 2.82 A$^(-1), and 3.28 A$^(-1). The relative intensities of the peaks suggest that the nanometer sized ice crystals created in a supersonic nozzle have a crystal structure that is close to pure cubic ice.