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Title: A new hybrid-Lagrangian numerical scheme for gyrokinetic simulation of tokamak edge plasma

In order to enable kinetic simulation of non-thermal edge plasmas at a reduced computational cost, a new hybrid-Lagrangian δf scheme has been developed that utilizes the phase space grid in addition to the usual marker particles, taking advantage of the computational strengths from both sides. The new scheme splits the particle distribution function of a kinetic equation into two parts. Marker particles contain the fast space-time varying, δf, part of the distribution function and the coarse-grained phase-space grid contains the slow space-time varying part. The coarse-grained phase-space grid reduces the memory-requirement and the computing cost, while the marker particles provide scalable computing ability for the fine-grained physics. Weights of the marker particles are determined by a direct weight evolution equation instead of the differential form weight evolution equations that the conventional delta-f schemes use. The particle weight can be slowly transferred to the phase space grid, thereby reducing the growth of the particle weights. The non-Lagrangian part of the kinetic equation – e.g., collision operation, ionization, charge exchange, heat-source, radiative cooling, and others – can be operated directly on the phase space grid. Deviation of the particle distribution function on the velocity grid from a Maxwellian distribution function – drivenmore » by ionization, charge exchange and wall loss – is allowed to be arbitrarily large. In conclusion, the numerical scheme is implemented in the gyrokinetic particle code XGC1, which specializes in simulating the tokamak edge plasma that crosses the magnetic separatrix and is in contact with the material wall.« less
ORCiD logo [1] ;  [1] ;  [1] ;  [2] ;  [3]
  1. Princeton Univ., Princeton, NJ (United States). Princeton Plasma Physics Lab.
  2. National Fusion Research Institute (Republic of Korea)
  3. Univ. of Colorado, Boulder, CO (United States)
Publication Date:
Report Number(s):
Journal ID: ISSN 0021-9991; PII: S0021999116300274
Grant/Contract Number:
AC02-09CH11466; SC000801; AC05-00OR22725
Accepted Manuscript
Journal Name:
Journal of Computational Physics
Additional Journal Information:
Journal Volume: 315; Journal Issue: C; Journal ID: ISSN 0021-9991
Research Org:
Princeton Plasma Physics Lab. (PPPL), Princeton, NJ (United States)
Sponsoring Org:
Contributing Orgs:
Princeton Plasma Physics Lab. (PPPL), Princeton, NJ (United States); National Fusion Research Institute, Republic of Korea; University of Colorado Boulder, USA
Country of Publication:
United States
70 PLASMA PHYSICS AND FUSION TECHNOLOGY; Plasma; Tokamak; Gyrokinetic; Lagrangian; delta-f; XGC
OSTI Identifier:
Alternate Identifier(s):
OSTI ID: 1325288