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Title: Ion-kinetic simulations of D- 3He gas-filled inertial confinement fusion target implosions with moderate to large Knudsen number

Experiments designed to investigate the transition to non-collisional behavior in D 3He-gas inertial confinement fusion target implosions display increasingly large discrepancies with respect to simulations by standard hydrodynamics codes as the expected ion mean-free-paths λ c increase with respect to the target radius R (i.e., when the Knudsen number N K = λ c/R grows). To take properly into account large N K's, multi-ion-species Vlasov-Fokker-Planck computations of the inner gas in the capsules have been performed, for two different values of N K, one moderate and one large. The results, including nuclear yield, reactivity-weighted ion temperatures, nuclear emissivities, and surface brightness, have been compared with the experimental data and with the results of hydrodynamical simulations, some of which include an ad hocmodeling of kinetic effects. The experimental results are quite accurately rendered by the kinetic calculations in the smaller-N K case, much better than by the hydrodynamical calculations. The kinetic effects at play in this case are thus correctly understood. However, in the higher-N K case, the agreement is much worse. Furthermore, the remaining discrepancies are shown to arise from kinetic phenomena (e.g., inter-species diffusion) occurring at the gas-pusher interface, which should be investigated in the future work.
 [1] ;  [2] ;  [3] ;  [4] ;  [5] ;  [6] ;  [2] ;  [6]
  1. CEA DIF, Arpajon Cedex (France)
  2. Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States)
  3. Univ. of Rochester, Rochester, NY (United States)
  4. Los Alamos National Lab. (LANL), Los Alamos, NM (United States)
  5. Univ. di Roma "La Sapienza" and CNISM, Roma (Italy)
  6. Massachusetts Inst. of Technology (MIT), Cambridge, MA (United States)
Publication Date:
Report Number(s):
Journal ID: ISSN 1070-664X
Grant/Contract Number:
Accepted Manuscript
Journal Name:
Physics of Plasmas
Additional Journal Information:
Journal Volume: 23; Journal Issue: 1; Journal ID: ISSN 1070-664X
American Institute of Physics (AIP)
Research Org:
Lawrence Livermore National Lab., Livermore, CA (United States)
Sponsoring Org:
Country of Publication:
United States
42 ENGINEERING; 70 PLASMA PHYSICS AND FUSION; hydrological modeling; interface diffusion; plasma temperature; helium-3; collision theories
OSTI Identifier: