Ab Initio Modeling of the Dynamical Stability of HED Plasmas: From Fusion to Astrophysics

PI Name: 
Frederico Fiuza
PI Email: 
fiuza@slac.stanford.edu
Institution: 
SLAC National Accelerator Laboratory
Allocation Program: 
ALCC
Allocation Hours at ALCF: 
60 Million
Year: 
2016
Research Domain: 
Physics

Fusion energy is regarded as a possible long-­term energy solution for humanity, capable of providing the energy resources to drive economic growth and social development. Fusion reactions  release  so  much  energy,  the  fusion  material  becomes  plasma.  In  the  inertial  confinement fusion (ICF) approach, a small pellet of fuel is hit with a high energy laser. The laser  instigates  a  fusion  reaction  inside  the  pellet.  The  reaction  creates  a  plasma  that  if  sufficiently  hot,  would  cause  ignition,  a  chain  reaction  allowing  the  full  pellet  to  undergo fusion and release vast amounts of energy. Ignition is the key to harnessing fusion energy in  the  ICF  approach.  However,  controlling  the  high  energy  hot  plasma  is  exceedingly  difficult and to date, ICF technology has not been able to achieve ignition.

Dynamical stability of converging plasmas has been recognized for decades as one of the most significant limitations to creating a sustained fusion reaction ignition. Hydrodynamic instabilities lead to non-­uniform compression and mixing of ablator material into the fuel, degrading the fusion yield. The numerical study of such instabilities in plasmas, which are also ubiquitous in astrophysical environments, such as supernovae, is typically conducted using  fluid  simulations.  Very  recently,  experimental  studies  have  started  to  shed  light  on  the  importance  of  kinetic  effects,  not  captured  in  fluid  simulations,  in  modifying  the dynamics of compression and ignition of fusion plasmas. However, the kinetic modeling of such systems has been out of reach due to the outstanding challenges posed by the large difference  in  scales  and  the  complexity  of  the  models  needed  to  capture  all  relevant  processes.  

This project supports first principles multi-­dimensional studies of the dynamical stability of  plasmas  using  kinetic  simulations,  thus  capturing  the  intrinsic  multi-­scale  physics  associated  with  fusion  plasmas.  This  project  will  take  advantage  of  a  suite  of  massively parallel  kinetic  codes  with  the  goal  of  identifying  the  regimes  for  which  kinetic  effects  impact  the  development  of  hydrodynamic  instabilities.  Outcomes  of  the  project  could ultimately lead to strategies to better control the dynamical stability of fusion plasmas and have an important impact in advancing DOE’s clean energy agenda.