Discontinuous Galerkin algorithms for fully kinetic plasmas

Juno, James; Hakim, Ammar; TenBarge, Jason; Shi, Eric; Dorland, W.

doi:10.1016/j.jcp.2017.10.009

Cited by 111 publications

(88 citation statements)

References 65 publications

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“…The five‐ and 10‐moment equation systems have been implemented in the finite‐volume version of the Gkeyll code, which uses a high‐resolution wave propagation method for the hyperbolic part of the equations and a point implicit method for the source terms (Hakim et al, ; Hakim, ), and has previously been used to study magnetic reconnection (Ng et al, , ; Wang et al, ). The kinetic simulations use the discontinuous Galerkin finite‐element Vlasov‐Maxwell solver of Gkeyll 2.0 (Juno et al, ). Because the Vlasov code uses a discontinuous Galerkin method, we require a basis function expansion in each cell, and we choose piecewise quadratic basis functions from the Serendipity Element family.…”

Section: Lower‐hybrid Drift Instabilitymentioning

confidence: 99%

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Drift Instabilities in Thin Current Sheets Using a Two‐Fluid Model With Pressure Tensor Effects

Hakim

Juno

et al. 2019

JGR Space Physics

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The integration of kinetic effects in fluid models is important for global simulations of the Earth's magnetosphere. We use a two‐fluid 10‐moment model, which includes the pressure tensor and has been used to study reconnection, to study the drift kink and lower hybrid drift instabilities. Using a nonlocal linear eigenmode analysis, we find that for the kink mode, the 10‐moment model shows good agreement with kinetic calculations with the same closure model used in reconnection simulations, while the electromagnetic and electrostatic lower hybrid instabilities require modeling the effects of the ion resonance using a Landau fluid closure. Comparisons with kinetic simulations and the implications of the results for global magnetospheric simulations are discussed.

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Section: Lower‐hybrid Drift Instabilitymentioning

confidence: 99%

“…Because the Vlasov code uses a discontinuous Galerkin method, we require a basis function expansion in each cell, and we choose piecewise quadratic basis functions from the Serendipity Element family. Details on the particulars of the basis expansion can be found in Arnold andAwanou (2011) andJuno et al (2018).…”

Section: Simulations Of the Lhdimentioning

confidence: 99%

Drift Instabilities in Thin Current Sheets Using a Two‐Fluid Model With Pressure Tensor Effects

Hakim

Juno

et al. 2019

JGR Space Physics

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“…The simulation framework we will use for this study is Gkeyll, which includes solvers for continuum Vlasov‐Maxwell (Juno et al., ), gyrokinetics (Shi et al., ), and five and ten‐moment two‐fluid equations (Hakim, ; Hakim et al., ; Wang et al., ). In this work, we focus on the five‐ and ten‐moment two‐fluid models.…”

Section: The Five‐ and Ten‐moment Modelsmentioning

confidence: 99%

“…Prior Gkeyll reconnection studies (Ng et al., ; Wang et al., ) have demonstrated that k 0 α d α ∼1 is required to achieve agreement with PIC simulations, where subscript α refers to species. However, a value of 1/10 provides slightly better performance for turbulence simulations without significantly degrading the reconnection performance (Juno et al., ). Since we expect these event simulations to be turbulent, we choose closure parameters for both ten‐moment model simulations to be k 0 α d α =1/10.…”

Section: Initial Conditionsmentioning

confidence: 99%

An Extended MHD Study of the 16 October 2015 MMS Diffusion Region Crossing

TenBarge

Juno

et al. 2019

JGR Space Physics

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The Magnetospheric Multiscale (MMS) mission has given us unprecedented access to high cadence particle and field data of magnetic reconnection at Earth's magnetopause. MMS first passed very near an X‐line on 16 October 2015, the Burch event, and has since observed multiple X‐line crossings. Subsequent 3‐D particle‐in‐cell (PIC) modeling efforts of and comparison with the Burch event have revealed a host of novel physical insights concerning magnetic reconnection, turbulence‐induced particle mixing, and secondary instabilities. In this study, we employ the Gkeyll simulation framework to study the Burch event with different classes of extended, multifluid magnetohydrodynamics (MHD), including models that incorporate important kinetic effects, such as the electron pressure tensor, with physics‐based closure relations designed to capture linear Landau damping. Such fluid modeling approaches are able to capture different levels of kinetic physics in global simulations and are generally less costly than fully kinetic PIC. We focus on the additional physics one can capture with increasing levels of fluid closure refinement via comparison with MMS data and existing PIC simulations. In particular, we find that the ten‐moment model well captures the agyrotropic structure of the pressure tensor in the vicinity of the X‐line and the magnitude of anisotropic electron heating observed in MMS and PIC simulations. However, the ten‐moment model is found to have difficulty resolving the lower hybrid drift instability, which plays a fundamental role in heating and mixing electrons in the current layer.

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“…A second class of kinetic algorithms is based on the propagation of the particle distribution function f in the sixdimensional position and velocity phase space x, y, z, v x , v y , v z , using the Boltzmann equation [e.g., 20] or the Vlasov equation in the collisionless case [e.g., [21][22][23][24][25][26][27][28][29][30][31][32][33][34][35][36]. These methods do not suffer from statistical noise but they are significantly heavier due to the higher-dimensional space to be sampled.…”

Section: Introductionmentioning

confidence: 99%