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Plasma in the terrestrial magnetosheath is characterised by very weak particle-particle collisions, so kinetic microinstabilities are thought to be responsible for regulating the thermodynamics of the plasma. By exciting electromagnetic…

Many models for anomalous transport consider the turbulent ExB transport arising from electrostatic micro-instabilities. In this paper we investigate whether the perturbed magnetic field that is associated with such instabilities at small…

Plasma Physics · Physics 2014-02-28 J W Connor , R J Hastie , A Zocco

We present that a statistical method known as the Complexity-Entropy analysis is useful to characterize a state of plasma turbulence and flux in the resonant magnetic perturbation (RMP) edge localized mode (ELM) control experiment. The RMP…

This paper uses the gyro-moment (GM) approach as a multi-fidelity tool to explore the effect of triangularity on tokamak edge turbulence. Considering experimental data from an L-mode DIII-D discharge, we conduct gyrokinetic (GK) simulations…

Plasma Physics · Physics 2024-07-19 A. C. D. Hoffmann , P. Ricci

This study delves into Microtearing Modes (MTMs) in tokamak plasmas, employing advanced simulations within the BOUT++ framework. The research, centering on collisional MTMs influenced by the time-dependent thermal force, enhances our…

Plasma Physics · Physics 2024-04-15 Kaixuan Fan , Xue-Qiao Xu , Ben Zhu , Chao Dong , Tianyang Xia , Zeyu Li

Models fail to reproduce observations of the coldest parts of the Sun's atmosphere, where interactions between multiple ionized and neutral species prevent an accurate MHD representation. This paper argues that a meter-scale electrostatic…

Solar and Stellar Astrophysics · Physics 2023-06-07 Samuel Evans , Meers Oppenheim , Juan Martínez-Sykora , Yakov Dimant , Richard Xiao

This paper reports on the refinement (building on Ref.~\cite{hatch_22}) and application of simple formulas for electron heat transport from electron temperature gradient (ETG) driven turbulence in the pedestal. The formulas are improved by…

Nonlinear simulations of Alfv\'en modes (AM) driven by energetic particles (EP) in the presence of turbulence are performed with the gyrokinetic particle-in-cell code ORB5. The AMs carry a heat flux, and consequently they nonlinearly modify…

The transport of heat and particles in the relatively collisional edge regions of magnetically confined plasmas is a scientifically challenging and technologically important problem. Understanding and predicting this transport requires the…

Plasma Physics · Physics 2017-04-26 Ben Dudson , Jarrod Leddy

The competition between the drive and stabilization of plasma microinstabilities by sheared flow is investigated, focusing on the ion temperature gradient mode. Using a twisting mode representation in sheared slab geometry, the…

Plasma Physics · Physics 2015-05-19 Sarah L. Newton , Steve C. Cowley , Nuno F. Loureiro

Small magnetic fluctuations ($B_1/B_0 \sim 10^{-4}$) are intrinsically present in a magnetic confinement plasma due to turbulent currents. While the perpendicular transport of particles and heat is typically dominated by fluctuations of the…

Plasma Physics · Physics 2025-01-10 Kaiyu Zhang , Wladimir Zholobenko , Andreas Stegmeir , Konrad Eder , Frank Jenko

We present a symplectic electromagnetic fully-kinetic particle-in-cell simulation of microinstabilities in plasma, using parameters from the Cyclone Base Case [Dimits, et al., Physics of Plasmas 7, 969 (2000)]. The results show that the…

Plasma Physics · Physics 2025-04-01 Jianyuan Xiao , Jian liu

The stability of a collisionless, magnetised plasma to local convective disturbances is examined, with a focus on kinetic and finite-Larmor-radius effects. Specific application is made to the outskirts of galaxy clusters, which contain hot…

High Energy Astrophysical Phenomena · Physics 2017-01-04 Rui Xu , Matthew W. Kunz

Turbulence simulations play a key role in advancing the general understanding of the physical properties turbulence and in interpreting astrophysical observations of turbulent plasmas. For the sake of simplicity, however, turbulence…

Astrophysics of Galaxies · Physics 2020-02-05 Philipp Grete , Brian W. O'Shea , Kris Beckwith

Future nuclear fusion reactors will have to confine plasma with strong kinetic gradients and small fractions of fusion-born energetic particles (EP) that are ~100 times hotter than the thermal ions. In our analysis, we assume the existence…

Turbulence characteristics of electron cyclotron (EC) and ohmic heated (OH) discharges has been analyzed by electrostatic gyrokinetic simulations with GYRO [J. Candy, R.E. Waltz, Journal of Computational Physics 186, 545-581 (2003)] aiming…

Plasma Physics · Physics 2011-04-08 Istvan Pusztai , Sara Moradi , Tunde Fulop , Natalia Timchenko

Transition to turbulence is due to the instability of a laminar flow subject to a disturbance. This complicated problem can be explained using a new proposed energy gradient theory in our previous study. This theory is extended to the…

Chaotic Dynamics · Physics 2007-05-23 Hua-Shu Dou

The closure problem of turbulence is still a challenging issue in turbulence modeling. In this work, a stability condition is used to close turbulence. Specifically, we regard single-phase flow as a mixture of turbulent and non-turbulent…

Fluid Dynamics · Physics 2014-06-20 Lin Zhang , Xiaoping Qiu , Limin Wang , Jinghai Li

In space and astrophysical plasmas, like in planetary magnetospheres, as that of Mercury,energetic electrons are often found near current sheets (CSs), which hints at electron acceleration by magnetic reconnection. Unfortunately, electron…

Plasma Physics · Physics 2018-07-04 X. Zhou , J. Buechner , F. Widmer , P. A. Munoz

The conventional ion temperature gradient or \eta_i mode is known to propagate in the ion diamagnetic direction. Investigation of a generic drift fluid model with warm ions and adiabatic electrons, reveals that as \eta_i decreases, the…

Plasma Physics · Physics 2022-03-17 Z. Y. Liu , Y. Z. Zhang , S. M. Mahajan , T. Xie