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In this work, we use the global electromagnetic and electrostatic gyro kinetic approaches to investigate the effects of zonal flows forced-driven by Alfv\'en modes due to their excitation by energetic particles (EPs), on the dynamics of ITG…

The ITG and TEM instabilities with quasi-coherent spectra have been identified experimentally, by the newly developed far-forward collective scattering measurements in J-TEXT tokamak Ohmical plasmas. The ITG mode has characteristic…

Plasma Physics · Physics 2023-10-27 Peng Shi , J. C. Li , G. Zhuang , Zhifeng Cheng , Li Gao , Yinan Zhou

Nonlinear multiscale gyrokinetic simulations of a Joint European Torus edge pedestal are used to show that electron-temperature-gradient (ETG) turbulence has a rich three-dimensional structure, varying strongly according to the local…

Strontium titanate is a classic quantum paraelectric oxide material that has been widely studied in bulk and thin films. It exhibits a well-known cubic-to-tetragonal antiferrodistortive phase transition at 105 K, characterized by the…

The transport of heat out of tokamak plasmas by turbulence is the dominant mechanism limiting the performance of fusion reactors. Turbulence can be driven by the ion temperature gradient (ITG) and suppressed by toroidal sheared flows.…

Plasma Physics · Physics 2017-03-20 Ferdinand van Wyk

We apply a continuation method to recently optimized stellarator equilibria with excellent quasi-axisymmetry (QA) to generate new equilibria with a wide range of rotational transform profiles. Using these equilibria, we investigate how the…

Plasma Physics · Physics 2024-01-18 Stefan Buller , Matt Landreman , John Kappel , Rahul Gaur

Turbulent transport remains one of the principal obstacles to achieving efficient magnetic confinement in fusion devices. Two of the dominant drivers of the turbulence are microscale instabilities fuelled by electron- and ion-temperature…

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

An analytic equilibrium, the Toroidal Bessel Function Model, is used in conjunction with the gyrokinetic code GYRO to investigate the nature of microinstabilities in a reversed field pinch (RFP) plasma. The effect of the normalized electron…

Plasma Physics · Physics 2015-06-12 Daniel Carmody , M. J. Pueschel , P. W. Terry

This paper combines results from a local gyrokinetic code with analytical theory to reconstruct the global eigenmode structure of the linearly unstable ion-temperature-gradient (ITG) mode with adiabatic electrons. The simulations presented…

Plasma Physics · Physics 2014-08-05 P. A. Abdoul , D. Dickinson , C. M. Roach , H. R. Wilson

Small-scale turbulence originating from microinstabilities limits the energy confinement time in magnetic confinement fusion. Here we develop a semi-analytical dispersion relation based on lowest-order solutions to the gyrokinetic equations…

Naturally stable to ELMs, and with widths larger than EPED predictions, the I-modes are an excellent laboratory for investigating the role of drift micro-instabilities in pedestals since I-mode pedestal are not "limited" by MHD…

Plasma Physics · Physics 2020-05-19 Xing Liu , M. Kotschenreuther , D. R. Hatch , S. M. Mahajan , J. W. Hughes , A. E. Hubbard

We analyze the gravitational instability (GI) of a locally isothermal inclined disk around one component of a binary system. Such a disk can undergo global Kozai-Lidov (KL) cycles if the initial disk tilt is above the critical KL angle (of…

Earth and Planetary Astrophysics · Physics 2017-02-08 Wen Fu , Stephen H. Lubow , Rebecca G. Martin

We have investigated linear and nonlinear dynamics of ion-temperature-gradient driven drift mode for Maxwellian and non Maxwellian pair-ion plasma embedded in an inhomogeneous magnetic field having gradients in ion's temperature and number…

Plasma Physics · Physics 2022-09-14 Javaria Razzaq , Zahida Ehsan , Arshad M. Mirza

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…

This study employs gyrokinetic simulations to investigate ion temperature gradient (ITG) turbulence in realistic fusion plasmas featuring reverse magnetic shear. Negative magnetic shear is found to suppress the ITG instability due to the…

Plasma Physics · Physics 2024-01-31 Dingkun Yang , Shengming Li , Yong Xiao , Zhihong Lin

In this work, we present the first global gyrokinetic simulations of the ITER baseline scenario operating at 15 MA using GENE-Tango electrostatic and electromagnetic simulations. The modeled radial region spans close to the magnetic axis up…

We have shown that there exists low-frequency growing modes driven by a global temperature gradient in electron and ion plasmas, by linear perturbation analysis within the frame work of plasma Kinetic theory. The driving force of the…

Astrophysics · Physics 2009-10-31 Makoto Hattori , Keiichi Umetsu

When dimensionality is reduced, enhanced quantum fluctuations can destroy long-range phase coherence, driving a superconductor insulator transition, SIT, where disorder and electronic correlations give rise to novel many-body states. Here,…

Mesoscale and Nanoscale Physics · Physics 2026-01-26 Phanibhusan S. Mahapatra , Haining Pan , Kenji Watanabe , Takashi Taniguchi , J. H. Pixley , Eva Y. Andrei

Gravitational instabilities (GIs) are spiral distortions in a self-gravitating disk that appear wherever the local surface density and temperature become favorable for their growth. The restructuring of the disk as it becomes unstable, the…

Astrophysics · Physics 2007-05-23 Annie C. Mejia