Code Description

Yang Chen, Scott Parker


GEM is a comprehensive electromagnetic gyrokinetic delta-f particle code that includes the full dynamics of gyrokinetic ions and drift-kinetic electrons. Magnetic perturbations perpendicular to the equilibrium field are fully modeled. The simulation is useful for studying well-magnetized plasma physics and is especially powerful because it is accurate at very-low fluctuation levels. Electron-ion collisions are included as well as the full-capability to model general axisymmetric toroidal equilibria.

Publications on GEM


  • An Implicit δf Particle-in-Cell Method with Sub-Cycling and Orbit Averaging for Lorentz Ions, B. J. Sturdevant, S. E. Parker, Y. Chen and B. B. Hause, J. Comp. Phys. (to appear, 2016)pdf
  • Gyrokinetic-ion drift-kinetic-electron simulation of the (m = 2, n = 1) cylindrical tearing mode, Y. Chen, J. Chowdhury, N. Maksimovic, S. E. Parker and W. Wan, Phys. Plasmas23, 056101 (2016)pdf
  • Particle-in-cell δf gyrokinetic simulations of the micro tearing mode, J. Chowdhury, Y. Chen, W. Wan, S. E. Parker, W. Guttenfelder and J. M. Canik, Phys. Plasmas23, 012513 (2016)
  • Finite time step and spatial grid effects in δ f simulation of warm plasmas, B. J. Sturdevant and S. E. Parker, J. Comp. Phys.305(2016) 647–663
  • Finite Larmor radius effects on the (m = 2, n = 1) cylindrical tearing mode, Y. Chen, J. Chowdhury, S. E. Parker and W. Wan, Phys. Plasmas22, 042111 (2015)
  • Spatially resolved measurements of two-dimensional turbulent structures in DIII-D plasmas, S. E. Zemedkun, S. Che, Y. Chen, C. W. Domier, N. C. Luhmann, Jr., T. Munsat, S. E. Parker, B. Tobias, W. Wan, and L. Yu, Phys. Plasmas22, 122508 (2015)
  • Effects of the magnetic equilibrium on gyrokinetic simulations of tokamak micro instabilities, W. Wan, Y. Chen, S. E. Parker and R. J. Groebner, Phys. Plasmas22, 062502 (2015)
  • Study of the L-mode tokamak plasma “shortfall” with local and global nonlinear gyrokinetic df particle-in-cell simulation, J. Chowdhury, Weigang Wan,Yang Chen, Scott E. Parker, Richard J. Groebner,C. Holland, and N. T. Howard, Phys. Plasmas21, 112503 (2014)
  • Benchmarking gyrokinetic simulations in a toroidal flux-tube, Y. Chen, S. E. Parker, W. Wan and R. Bravenec Phys. Plasmas20, 092511 (2013)
  • A verification of the gyrokinetic microstability codes GEM, GYRO, and GS2, R. V. Bravenec, Y. Chen, J. Candy, W. Wan and S. Parker, Phys. Plasmas20, 104506 (2013)
  • Measurements and simulations of low-wavenumber pedestal turbulence in the National Spherical Torus Experiment, D.R. Smith, S.E. Parker, W. Wan, Y. Chen, A. Diallo, B.D. Dudson, R.J. Fonck, W. Guttenfelder, G.R. McKee and S.M. Kaye, Nucl. Fusion53, 1123029 (2013)
  • A second-order semi-implicit df method for hybrid simulation, Jianhua Cheng, Scott E. Parker, Yang Chen, Dmitri A. Uzdensky, Journal of Computational Physics 245 (2013) 364–375
  • Global gyrokinetic simulations of the H-mode tokamak edge pedestal, W. Wan, S. E. Parker, Y. Chen, R. J. Groebner, Z. Yan, A. Y. Pankin, and S. E. Kruger, Phys. Plasmas20, 055902 (2013)
  • Comparison of Kinetic and Extended MHD Computational Models for the Linear Ion Temperature Gradient Instability in Slab Geometry, D. D. Schnack, J. Cheng, D. Barnes and S. Parker, Phys. Plasmas20, 062106 (2013)
  • Gyrokinetic simulations of reverse shear Alfvén eigenmodes in DIII-D plasmas, Y. Chen, T. Munsat, S. E. Parker, W. W. Heidbrink, M. A. Van Zeeland, B. J. Tobias, and C. W. Domier, Phys. Plasmas20, 012109 (2013)
  • Linear gyrokinetic analysis of a DIII-D H-mode pedestal near the ideal ballooning threshold, E. Wang, X. Xu, J. Candy, R. J. Groebner, P. B. Snyder, Y. Chen, S. E. Parker, W. Wan, G. Lu , and J. Q. Dong, Nucl. Fusion52, 103015 (2012)
  • Global Gyrokinetic Simulation of Tokamak Edge Pedestal Instabilities, W. Wan, S. E. Parker, Y. Chen, Z. Yan, R. J. Groebner, and P. B. Snyder, Phys. Rev. Lett.109, 185004 (2012)
  • The pinch of cold ions from recycling in the tokamak edge pedestal, W. Wan, S. E. Parker, Y. Chen, G.-Y. Park, C.-S. Chang, and D. Stotler, Phys. Plasmas18,056116 (2011)
  • Fluid electrons with kinetic closure for long wavelength energetic particles driven modes, Y. Chen and S. E. Parker, Phys. Plasmas18,055703 (2011)
  • L-mode validation studies of gyrokinteic turbulence simulations via multiscale and multifield turbulence measurements on the DIII-D tokamak, T.L. Rhodes, C. Holland, S.P. Smith, A.E. White, K.H. Burrell, J. Candy, J.C. DeBoo, E.J. Doyle, J.C. Hillesheim, J.E. Kinsey, G.R. McKee, D. Mikkelsen, W.A. Peebles, C.C. Petty, R. Prater, S. Parker, Y. Chen, L. Schmitz, G.M. Staebler, R.E. Waltz, G. Wang, Z. Yan and L. Zeng, Nucl. Fusion51,063022 (2011)
  • Linear gyrokinetic simulation of high-n toroidal Alfvén eigenmodes in a burning plasma, Y. Chen, S. E. Parker, J. Lang and G.-Y. Fu, Phys. Plasmas17,102504 (2010)
  • Natural fueling of a tokamak fusion reactor, W. Wan, S. E. Parker, Y. Chen and F.W. Perkins, Phys. Plasmas17,040701 (2010)
  • Gyrokinetic delta-f particle simulations of toroidicity-induced Alfvén eigenmode, J. Lang, Y. Chen, S. E. Parker, and G.-Y. Fu, Phys. Plasmas16,102101 (2009)
  • Particle-in-Cell simulation with Vlasov ions and drift-kinetic electrons, Y. Chen & S. E. Parker, Phys. Plasmas 16,052305(2009)
  • Role of zonal flows in TEM turbulence through nonlinear gyrokinetic particle and continuum simulation, D.R. Ernst, J. Lang, W. Nevins, M. Hoffman, Y. Chen, W. Dorland and S. Parker, Phys. Plasmas 16,055906(2009) ()
  • Low-noise particle algorithms for extended magnetohydrodynamic closure, D.C. Barnes, J. Cheng and S. E. Parker, Phys. Plasmas15,055702 (2008)
  • Nonlinear saturation of collisionless trapped electron mode turbulence: zonal flows and zonal density, J. Lang, Y. Chen and S. E. Parker,Phys. Plasmas 15,055907(2008) ()
  • Coarse-graining the electron distribution in turbulence simulations of tokamak plasmas, Y. Chen, S. E. Parker, G. Rewoldt, S. Ku, G. Y. Park &C-S. Chang,Phys. Plasmas 15,055905(2008) ()
  • Verification of gyrokinetic delta-f simulations of electron temperature gradient turbulence, B. Nevins, Y. Chen and S. E. Parker, Physics of Plasmas 14,084501(2007) ()
  • Gyrokinetic delta-f particle simulation of trapped electron mode driven turbulence, J. Lang, Y. Chen and S. Parker, Physics of Plasmas 14, 082315 (2007).
  • Coarse-graining phase space in delta-f particle-in-cell simulations,Y. Chen and S. Parker, Physics of Plasmas 14, 082301 (2007).
  • Electromagnetic gyrokinetic delta-f particle-in-cell turbulence simulation with realistic equilibrium profiles and geometry, Y. Chen and S. Parker,J. of Comp. Phys.220839 (2007).
  • Fine-scale zonal flow suppression of electron temperature gradient turbulence, S. Parker, J. Kohut, Y. Chen, Z. Lin, F. Hinton, W. Lee,AIP Conference Proceedings871193-203 (2006).
  • Arbitrary plasma shape and trapped electron modes in the GEM gyrokinetic electromagnetic turbulence simulation code, Y. Chen, S. Parker, J. Lang,Journal of Physics: Conference Series4692-96 (2006).
  • Relevance of the parallel nonlinearity in gyrokinetic simulations of tokamak plasmas, J. Candy, R. Waltz, S. Parker, Y. Chen,Phys. Plasmas13074501 (2006).
  • Gyrokinetic delta-f simulation of the collisionless and semicollisonal tearing mode instability, W. Wan, Y. Chen and S. Parker,Phys. Plasmas12012311-1 (2005).
  • Electromagnetic gyrokinetic simulations, S. Parker, Y. Chen and W. Wan,Phys. Plasmas112594 (2004).
  • The particle-continuum method: an algorithmic unification of particle-in-cell and continuum methods, S. Vadlamani, S. Parker, Y. Chen and C. Kim,Comp. Phys. Comm.,164209 (2004).
  • A delta-f particle method for gyrokinetic simulations with kinetic electrons and electromagnetic perturbuations, Y. Chen and S. Parker,J. Comput. Phys.189463 (2003).
  • Simulations of turbulent transport with kinetic electrons and electromagnetic effects, Y. Chen, S. Parker, B. Cohen, A. Dimits, W. Nevins, D. Shumaker, V. Decyk and J. Leboeuf,Nucl. Fusion431121 (2003).
  • Gyrokinetic simulations with kinetic electrons, Y. Chen and S. Parker, Phys. Plasmas82095 (2001).
  • A gyrokinetic ion zero electron inertia fluid electron model for turbulence simulations, Y. Chen and S. Parker,Phys. Plasmas8441 (2001).
  • Electromagnetic gyrokinetic ion drift-fluid-electron hybrid simulation, S. Parker, Y. Chen and C. Kim,Comp. Phys. Comm. Phs.12759 (2000).
  • Large-scale gyrokinetic turbulence simulations: Effects of profile variation, S. Parker, C. Kim and Y. Chen,Phys. Plasmas61709 (1999).