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 未f 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)听pdf
  • Gyrokinetic-ion drift-kinetic-electron simulation of the (m鈥=鈥2, n鈥=鈥1) cylindrical tearing mode, Y. Chen, J. Chowdhury, N. Maksimovic, S. E. Parker and W. Wan, Phys. Plasmas听23, 056101 (2016)pdf
  • Particle-in-cell 未f gyrokinetic simulations of the micro tearing mode, J. Chowdhury, Y. Chen, W. Wan, S. E. Parker, W. Guttenfelder and J. M. Canik, Phys. Plasmas听23, 012513 (2016)听
  • Finite time step and spatial grid effects in 未 f simulation of warm plasmas, B. J. Sturdevant and S. E. Parker, J. Comp. Phys.听305听(2016) 647鈥663听
  • Finite Larmor radius effects on the (m鈥=鈥2, n鈥=鈥1) cylindrical tearing mode, Y. Chen, J. Chowdhury, S. E. Parker and W. Wan, Phys. Plasmas听22, 042111 (2015)听
  • 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. Plasmas听22, 122508 (2015)听
  • Effects of the magnetic equilibrium on gyrokinetic simulations of tokamak micro instabilities, W. Wan, Y. Chen, S. E. Parker and R. J. Groebner, Phys. Plasmas听22, 062502 (2015)听
  • Study of the L-mode tokamak plasma 鈥渟hortfall鈥 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. Plasmas听21, 112503 (2014)听
  • Benchmarking gyrokinetic simulations in a toroidal flux-tube, Y. Chen, S. E. Parker, W. Wan and R. Bravenec Phys. Plasmas20, 092511 (2013)听
  • A verification of the gyrokinetic microstability codes GEM, GYRO, and GS2, R. V. Bravenec, Y. Chen, J. Candy, W. Wan and S. Parker, Phys. Plasmas听20, 104506 (2013)听
  • 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. Fusion听53, 1123029 (2013)听
  • 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鈥375听
  • 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. Plasmas听20, 055902 (2013)听
  • 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. Plasmas听20, 062106 (2013)听
  • Gyrokinetic simulations of reverse shear Alfv茅n 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. Plasmas听20, 012109 (2013)听
  • Linear gyrokinetic analysis of a DIII-D H-mode pedestal near the ideal ballooning threshold, E. Wang, X. Xu, J. Candy, R.鈥塉. Groebner, P.鈥塀. Snyder, Y. Chen, S.鈥塃. Parker, W. Wan, G. Lu , and J.鈥塓. Dong, Nucl. Fusion听52, 103015 (2012)听
  • 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.听109, 185004 (2012)听
  • 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. Plasmas听18,听056116 (2011)听
  • Fluid electrons with kinetic closure for long wavelength energetic particles driven modes, Y. Chen and S. E. Parker, Phys. Plasmas听18,听055703 (2011)听
  • 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. Fusion听51,听063022 (2011)听
  • Linear gyrokinetic simulation of high-n toroidal Alfv茅n eigenmodes in a burning plasma, Y. Chen, S. E. Parker, J. Lang and G.-Y. Fu, Phys. Plasmas听17,听102504 (2010)听
  • Natural fueling of a tokamak fusion reactor, W. Wan, S. E. Parker, Y. Chen and F.W. Perkins, Phys. Plasmas听17,听040701 (2010)听
  • Gyrokinetic delta-f particle simulations of toroidicity-induced Alfv茅n eigenmode, J. Lang, Y. Chen, S. E. Parker, and G.-Y. Fu, Phys. Plasmas听16,听102101 (2009)听
  • Particle-in-Cell simulation with Vlasov ions and drift-kinetic electrons, Y. Chen & S. E. Parker, Phys. Plasmas 16,听052305听(2009)听
  • 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,听 Phys. Plasmas 16,听055906听(2009) ()
  • Low-noise particle algorithms for extended magnetohydrodynamic closure, D.C. Barnes, J. Cheng and S. E. Parker, Phys. Plasmas听15,听055702 (2008)听
  • Nonlinear saturation of 听collisionless trapped electron mode turbulence: zonal flows and zonal 听density, J. Lang, Y. Chen and S. E. Parker,听Phys. Plasmas 15,听055907听(2008) ()
  • Coarse-graining the electron distribution in turbulence simulations of tokamak plasmas, Y. Chen, S. E. Parker, G. Rewoldt, S. Ku, G. Y. Park &听C-S. Chang,听Phys. Plasmas 15,听055905听(2008) ()
  • Verification of gyrokinetic delta-f simulations of electron temperature gradient turbulence, B. Nevins, Y. Chen and S. E. Parker, Physics of Plasmas 14,听084501听(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).听
  • Coarse-graining phase space in delta-f particle-in-cell simulations,听Y. Chen and S. Parker, Physics of Plasmas 14, 082301 (2007).听
  • Electromagnetic gyrokinetic delta-f particle-in-cell turbulence simulation with realistic equilibrium profiles and geometry, Y. Chen and S. Parker,听J. of Comp. Phys.220听839 (2007).听
  • Fine-scale zonal flow suppression of electron temperature gradient turbulence, S. Parker, J. Kohut, Y. Chen, Z. Lin, F. Hinton, W. Lee,听AIP Conference Proceedings871听193-203 (2006).听
  • Arbitrary plasma shape and trapped electron modes in the GEM gyrokinetic electromagnetic turbulence simulation code, Y. Chen, S. Parker, J. Lang,听Journal of Physics: Conference Series4692-96 (2006).听
  • Relevance of the parallel nonlinearity in gyrokinetic simulations of tokamak plasmas, J. Candy, R. Waltz, S. Parker, Y. Chen,听Phys. Plasmas13听074501 (2006).听
  • Gyrokinetic delta-f simulation of the collisionless and semicollisonal tearing mode instability, W. Wan, Y. Chen and S. Parker,听Phys. Plasmas12听012311-1 (2005).听
  • Electromagnetic gyrokinetic simulations, S. Parker, Y. Chen and W. Wan,听Phys. Plasmas11听2594 (2004).听
  • The particle-continuum method: an algorithmic unification of particle-in-cell and continuum methods, S. Vadlamani, S. Parker, Y. Chen and C. Kim,听Comp. Phys. Comm.,听164听209 (2004).听
  • A delta-f particle method for gyrokinetic simulations with kinetic electrons and electromagnetic perturbuations, Y. Chen and S. Parker,听J. Comput. Phys.189听463 (2003).听
  • 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,听Nucl. Fusion43听1121 (2003).听
  • Gyrokinetic simulations with kinetic electrons, Y. Chen and S. Parker, Phys. Plasmas听8听2095 (2001).听
  • A gyrokinetic ion zero electron inertia fluid electron model for turbulence simulations, Y. Chen and S. Parker,听Phys. Plasmas8听441 (2001).听
  • Electromagnetic gyrokinetic ion drift-fluid-electron hybrid simulation, S. Parker, Y. Chen and C. Kim,听Comp. Phys. Comm. Phs.127听59 (2000).听
  • Large-scale gyrokinetic turbulence simulations: Effects of profile variation, S. Parker, C. Kim and Y. Chen,听Phys. Plasmas6听1709 (1999).听