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Related papers: Multiscale turbulence in stellarators

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We show that zonal flow can be preferentially excited by intermediate-scale toroidal electron temperature gradient (ETG) turbulence in tokamak plasmas. Previous theoretical studies that yielded an opposite conclusion assumed a fluid…

Plasma Physics · Physics 2021-05-26 Haotian Chen , Stefan Tirkas , Scott E. Parker

Global gyrokinetic simulations find a strong suppression of ion temperature gradient (ITG) turbulence by zonal flows in stellarators optimized for neoclassical transport. The reduction of the ITG transport by the zonal flows in…

Plasma Physics · Physics 2025-05-29 Haotian Chen , Xishuo Wei , Hongxuan Zhu , 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…

Differential rotation is known to suppress linear instabilities in fusion plasmas. However, even in the absence of growing eigenmodes, subcritical fluctuations that grow transiently can lead to sustained turbulence. Here transient growth of…

Plasma Physics · Physics 2015-08-26 A. A. Schekochihin , E. G. Highcock , S. C. Cowley

The first experimental campaigns have proven that, due to the optimization of the magnetic configuration with respect to neoclassical transport, the contribution of turbulence is essential to understand and predict the total particle and…

H-mode operation of tokamak fusion plasmas free of dangerous Type 1 edge-localized-modes (ELMs) requires a non-ELM mechanism for saturating the edge pedestal growth. One possible mechanism is turbulent transport. We introduce a transport…

Plasma Physics · Physics 2025-05-15 J. F. Parisi , D. R. Hatch , P. Y. Li , J. W. Berkery , A. O. Nelson , S. M. Kaye , K. Imada , M. Lampert

Microturbulence in magnetic confined plasmas contributes to energy exchange between particles of different species as well as the particle and heat fluxes. Although the effect of turbulent energy exchange has not been considered significant…

Plasma Physics · Physics 2024-06-18 T. Kato , H. Sugama , T. -H. Watanabe , M. Nunami

Electromagnetic (EM) instabilities and turbulence driven by the electron-temperature gradient are considered in a local slab model of a tokamak-like plasma. The model describes perturbations at scales both larger and smaller than the…

Plasma Physics · Physics 2022-08-30 T. Adkins , A. A. Schekochihin , P. G. Ivanov , C. M. Roach

The saturated state of turbulence driven by the ion-temperature-gradient instability is investigated using a two-dimensional long-wavelength fluid model that describes the perturbed electrostatic potential and perturbed ion temperature in a…

Plasma Physics · Physics 2023-01-18 P. G. Ivanov , A. A. Schekochihin , W. Dorland , A. R. Field , F. I. Parra

Ion temperature gradient(ITG) and trapped electron modes(TEM) driven turbulent transport in an ITER-like plasma is investigated by means of multi-species gyrokinetic Vlasov simulations with D, T, He, and real-mass kinetic electrons…

Plasma Physics · Physics 2026-02-27 Motoki Nakata , Mitsuru Honda

The impact of electromagnetic stabilization and flow shear stabilization on ITG turbulence is investigated. Analysis of a low-$\beta$ JET L-mode discharge illustrates the relation between ITG stabilization, and proximity to the…

Magnetised plasma turbulence can have a multiscale character: instabilities driven by mean temperature gradients drive turbulence at the disparate scales of the ion and the electron gyroradii. Simulations of multiscale turbulence, using…

Plasma Physics · Physics 2020-11-25 M. R. Hardman , M. Barnes , C. M. Roach

The first experimental campaigns of Wendelstein 7-X (W7-X) have shown that turbulence plays a decisive role in the performance of neoclassically optimized stellarators. This stresses the importance of understanding microturbulence from the…

The characteristics of ion temperature gradient (ITG) turbulence in the presence of a magnetic island are numerically investigated using a gyrokinetic model. We observe that in the absence of the usual ITG drive gradient, a solitary…

Plasma Physics · Physics 2023-12-29 Jingchun Li , J. Bao , Z. Lin , J. Q. Dong , Yong Liu , Y. R. Qu

The derivation of an intermediate-scale gyrokinetic-electron theory in nonuniform tokamak plasmas [Chen H. et al 2021 Nucl. Fusion 61 066017] has shown that a Navier-Stokes type nonlinearity couples electron-temperature-gradient (ETG) modes…

Plasma Physics · Physics 2023-01-05 Stefan Tirkas , Haotian Chen , Gabriele Merlo , Frank Jenko , Scott Parker

A geometrical method is used for the analysis of stochastic processes in plasma turbulence. Distances between thermodynamic states can be computed according the thermodynamic length methodology which allows the use of a Riemannian metric on…

Plasma Physics · Physics 2023-06-28 A. D. Papadopoulos , J. Anderson , E-J. Kim , M. Mavridis , H. Isliker

Turbulent transport is a decisive factor in determining the pedestal structure of H-modes. Here, we present the first comprehensive characterization of gyrokinetic turbulent transport in a JET hybrid H-mode pedestal. Local, linear…

Plasma Physics · Physics 2024-05-20 L. A. Leppin , T. Görler , L. Frassinetti , S. Saarelma , J. Hobirk , F. Jenko , JET contributors

We investigate the ExB diffusion of fusion born \alpha particles in tokamak plasmas. We determine the transport regimes for a realistic model that has the characteristics of the ion temperature gradient (ITG) or of the trapped electron…

Plasma Physics · Physics 2017-02-01 A. Croitoru , D. I. Palade , M Vlad , F Spineanu

A reproducible stationary improved confinement mode (I-mode) has been achieved recently in the Experimental Advanced Superconducting Tokamak, featuring good confinement without particle transport barrier, which could be beneficial to…

The Large Volume Plasma device(LVPD), a cylindrically shaped, linear plasma device of dimension( $\phi =2m $, $ L =3m $) have successfully demonstrated the excitation of Electron Temperature Gradient(ETG) turbulence[ Mattoo et al.,[1]]. The…