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In the present Letter, first-of-its-kind computer simulations predicting plasma profiles for modern optimized stellarators -- while self-consistently retaining neoclassical transport, turbulent transport with 3D effects, and external…

Simulations of isolated giant molecular clouds (GMCs) are an important tool for studying the dynamics of star formation, but their turbulent initial conditions (ICs) are uncertain. Most simulations have either initialized a velocity field…

The gyrokinetic turbulence code GS2 was used to investigate the effects of plasma beta on linear, collisionless ion temperature gradient (ITG) modes and trapped electron modes (TEM) in National Compact Stellarator Experiment (NCSX)…

Plasma Physics · Physics 2013-03-05 J. A. Baumgaertel , G. W. Hammett , D. R. Mikkelsen , M. Nunami , P. Xanthopoulos

We present a comparative study of transport in two optimized stellarator configurations: Wendelstein 7-X (W7-X) and a recent design called Quasi-Symmetric Turbulence Konzept (QSTK). Using global Gyrokinetic Toroidal Code (GTC), we explore…

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…

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…

While many intermediate- and high-mass main sequence stars are rapidly and differentially rotating, the effects of rotation on oscillation modes are poorly known. In this communication we present a first study of axisymmetric…

Solar and Stellar Astrophysics · Physics 2014-11-14 Giovanni M. Mirouh , Clément Baruteau , Michel Rieutord , Jérôme Ballot

Results of a three-dimensional, flux-driven, electrostatic, global, two-fluid turbulence simulation for a 5-field period stellarator with an island divertor are presented. The numerical simulation is carried out with the GBS code, recently…

Plasma Physics · Physics 2022-06-01 A. J. Coelho , J. Loizu , P. Ricci , M. Giacomin

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

We present the first nonlinear, gyrokinetic, radially global simulation of a discharge of the Wendelstein 7-X-like stellarator (W7-X), including kinetic electrons, an equilibrium radial electric field, as well as electromagnetic and…

A photoionized gas under constant pressure can display a thermal instability, with three or more solutions for possible thermal equilibrium. A unique solution of the structure of the irradiated medium is obtained only if electron conduction…

Instrumentation and Methods for Astrophysics · Physics 2015-05-13 B. Czerny , L. Chevallier , A. C. Goncalves , A. Rozanska , A. -M. Dumont

The indirect nonlinear interactions between toroidal Alfv\'en eigenmode (TAE) and ion temperature gradient mode (ITG) are investigated using nonlinear gyrokinetic theory and ballooning mode formalism. More specifically, the local nonlinear…

Plasma Physics · Physics 2024-08-29 Qian Fang , Guangyu Wei , Ningfei Chen , Liu Chen , Fulvio Zonca , Zhiyong Qiu

Global gradient driven GENE gyrokinetic simulations are used to investigate TCV plasmas with negative triangularity. Considering a limited L-mode plasma, corresponding to an experimental triangularity scan, numerical results are able to…

Plasma Physics · Physics 2021-01-18 G. Merlo , Z. Huang , C. Marini , S. Brunner , S. Coda , D. Hatch , D. Jarema , F. Jenko , O. Sauter , L. Villard

Isothermal fluid turbulence simulations have been performed in the edge and scrape-off-layer (SOL) of an analytic stellarator configuration with an island divertor, thereby providing numerical insight into edge turbulence in regions around…

Plasma Physics · Physics 2024-03-28 Brendan Shanahan , David Bold , Ben Dudson

We demonstrate that the universal mode driven by the density gradient in a plasma slab can be absolutely unstable even in the presence of reasonable magnetic shear. Previous studies from the 1970s that reached the opposite conclusion used…

Plasma Physics · Physics 2015-06-23 Matt Landreman , Thomas M Antonsen , William Dorland

We investigate the linear and nonlinear properties of the Goldreich-Schubert-Fricke (GSF) instability in stellar radiative zones with arbitrary local (radial and latitudinal) differential rotation. This instability may lead to turbulence…

Solar and Stellar Astrophysics · Physics 2023-07-12 Robert W. Dymott , Adrian J. Barker , Chris A. Jones , Steven M. Tobias

We investigate the effect of varying the ion temperature gradient (ITG) and toroidal equilibrium scale sheared flow on ion-scale turbulence in the outer core of MAST by means of local gyrokinetic simulations. We show that nonlinear…

Plasma Physics · Physics 2017-10-11 F. van Wyk , E. G. Highcock , A. R. Field , C. M. Roach , A. A. Schekochihin , F. I. Parra , W. Dorland

The effect of island width on the multi-scale interactions between magnetic island (MI) and ion temperature gradient (ITG) turbulence has been investigated based on the global gyrokinetic approach. It is found that the coupling between the…

Plasma Physics · Physics 2023-08-09 J. C. Li , J. Q. Xu , Y. R. Qu , Z. Lin , J. Q. Dong , X. D. Peng , J. Q. Li

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

With the increase in computational capabilities over the last years it becomes possible to simulate more and more complex and accurate physical models. Gyrokinetic theory has been introduced in the 1960s and 1970s in the need of describing…

Plasma Physics · Physics 2024-02-12 Mario Raeth , Klaus Hallatschek , Katharina Kormann