Modeling of Intense X-­ray Laser Dynamics in Nanoclusters

PI Name: 
Phay Ho
PI Email: 
pho@anl.gov
Institution: 
Argonne National Laboratory
Allocation Program: 
ALCC
Allocation Hours at ALCF: 
10 Million
Year: 
2016
Research Domain: 
Materials Science

X-­rays are light waves with wavelengths on the size of atoms to biological cells. Because of their atom to cell sized wavelengths, x-­rays have been an invaluable probe for science on the nanoscale. Key to using x-­rays is the understanding of how x-­rays interact with matter. This  project  supports  the  development  of  a  fundamental  understanding  of  the  dynamical  processes induced by intense x-­rays in complex systems. The ultrahigh intensity regime of x-­ray interactions with matter was initiated with the advent of the LCLS x-­ray free-­electron laser (XFEL). The intensities in both the soft and hard x-­ray regime can strip electrons from atoms  from  the  inside  out  and  create  transient  states  of  matter  as  the  x-­ray  pulse  progresses through the target. Using nanoscale clusters, particular attention is paid to the ionization  dynamics  starting  on  the  atomic  level,  the  nanoplasma  formation,  and  the  implications  of  the  rapidly  changing  sample  to  the  ultrafast  x-­ray  scattering  process.  A hybrid  quantum/classical  simulation  methodology  will  be  used  to  investigate  the  interactions  of  intense  XFEL  pulses  with  nanoscale  samples  to  understand  the  ultrafast dynamics and its connection to x-­ray imaging. This work is proposed is an important step forward  in  understanding  high-­brightness,  coherent  x-­ray  laser  pulses  and  their  interactions  with  matter.  The  completion  of  the  proposed  work  will  enhance  capabilities 10,000-fold  and  establish  the  applied  methodology  as  an  effective  large-­scale  computational tool for the new research frontier of ultrafast x-­ray science.