A new hybridLagrangian numerical scheme for gyrokinetic simulation of tokamak edge plasma
In order to enable kinetic simulation of nonthermal edge plasmas at a reduced computational cost, a new hybridLagrangian 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 spacetime varying, δf, part of the distribution function and the coarsegrained phasespace grid contains the slow spacetime varying part. The coarsegrained phasespace grid reduces the memoryrequirement and the computing cost, while the marker particles provide scalable computing ability for the finegrained 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 deltaf schemes use. The particle weight can be slowly transferred to the phase space grid, thereby reducing the growth of the particle weights. The nonLagrangian part of the kinetic equation – e.g., collision operation, ionization, charge exchange, heatsource, 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 »
 Authors:

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 Princeton Univ., Princeton, NJ (United States). Princeton Plasma Physics Lab.
 National Fusion Research Institute (Republic of Korea)
 Univ. of Colorado, Boulder, CO (United States)
 Publication Date:
 Report Number(s):
 PPPL5212
Journal ID: ISSN 00219991; PII: S0021999116300274
 Grant/Contract Number:
 AC0209CH11466; SC000801; AC0500OR22725
 Type:
 Accepted Manuscript
 Journal Name:
 Journal of Computational Physics
 Additional Journal Information:
 Journal Volume: 315; Journal Issue: C; Journal ID: ISSN 00219991
 Publisher:
 Elsevier
 Research Org:
 Princeton Plasma Physics Lab. (PPPL), Princeton, NJ (United States)
 Sponsoring Org:
 USDOE
 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
 Language:
 English
 Subject:
 70 PLASMA PHYSICS AND FUSION TECHNOLOGY; Plasma; Tokamak; Gyrokinetic; Lagrangian; deltaf; XGC
 OSTI Identifier:
 1254687
 Alternate Identifier(s):
 OSTI ID: 1325288
Ku, S., Hager, R., Chang, C. S., Kwon, J. M., and Parker, S. E.. A new hybridLagrangian numerical scheme for gyrokinetic simulation of tokamak edge plasma. United States: N. p.,
Web. doi:10.1016/j.jcp.2016.03.062.
Ku, S., Hager, R., Chang, C. S., Kwon, J. M., & Parker, S. E.. A new hybridLagrangian numerical scheme for gyrokinetic simulation of tokamak edge plasma. United States. doi:10.1016/j.jcp.2016.03.062.
Ku, S., Hager, R., Chang, C. S., Kwon, J. M., and Parker, S. E.. 2016.
"A new hybridLagrangian numerical scheme for gyrokinetic simulation of tokamak edge plasma". United States.
doi:10.1016/j.jcp.2016.03.062. https://www.osti.gov/servlets/purl/1254687.
@article{osti_1254687,
title = {A new hybridLagrangian numerical scheme for gyrokinetic simulation of tokamak edge plasma},
author = {Ku, S. and Hager, R. and Chang, C. S. and Kwon, J. M. and Parker, S. E.},
abstractNote = {In order to enable kinetic simulation of nonthermal edge plasmas at a reduced computational cost, a new hybridLagrangian 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 spacetime varying, δf, part of the distribution function and the coarsegrained phasespace grid contains the slow spacetime varying part. The coarsegrained phasespace grid reduces the memoryrequirement and the computing cost, while the marker particles provide scalable computing ability for the finegrained 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 deltaf schemes use. The particle weight can be slowly transferred to the phase space grid, thereby reducing the growth of the particle weights. The nonLagrangian part of the kinetic equation – e.g., collision operation, ionization, charge exchange, heatsource, 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 – driven 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.},
doi = {10.1016/j.jcp.2016.03.062},
journal = {Journal of Computational Physics},
number = C,
volume = 315,
place = {United States},
year = {2016},
month = {4}
}