A four-field gyrofluid model with neoclassical effects for the study of the rotation velocity of magnetic islands in tokamaks

Kód výsledku v IS VaVaI

<a href="https://www.isvavai.cz/riv?ss=detail&h=RIV%2F61389021%3A_____%2F18%3A00493076" target="_blank" >RIV/61389021:_____/18:00493076 - isvavai.cz</a>

Výsledek na webu

<a href="https://aip.scitation.org/doi/10.1063/1.5036648" target="_blank" >https://aip.scitation.org/doi/10.1063/1.5036648</a>

DOI - Digital Object Identifier

<a href="http://dx.doi.org/10.1063/1.5036648" target="_blank" >10.1063/1.5036648</a>

Jazyk výsledku

angličtina

Název v původním jazyce

A four-field gyrofluid model with neoclassical effects for the study of the rotation velocity of magnetic islands in tokamaks

Popis výsledku v původním jazyce

A four-field system of equations which includes the neoclassical flow damping effects and the lowest-order finite-Larmor-radius (FLR) corrections is deduced from a system of gyrofluid equations. The FLR corrections to the poloidal flow damping are calculated by solving a simplified version of the gyrokinetic equation. This system of equations is applied to the study of a chain of freely rotating magnetic islands in a tokamak, resulting from the nonlinear evolution of a resistive tearing mode, to determine the island rotation velocity consistently with the fields' radial profiles close to the resonant surface. The island rotation velocity is determined by imposing the torque balance condition. The equations thus deduced are applied to the study of two different collisionality regimes, namely the weak-damping regime and the intermediate-damping regime. The equations reduce, in the weak-damping regime, to a form already obtained in previous works, while an additional term, containing the lowest order FLR corrections to the poloidal flow damping, appears in the intermediate-damping regime. The numerical integration of the final system of equations allows the determination of the dependence of the island rotation velocity on the plasma collisionality and the island width compared to the ion Larmor radius. The results show that, in the intermediate-damping regime, the island rotation velocity is almost completely determined by the neoclassical effects, with the island width playing a minor role. The parameter η i = L n / L T, where Ln and LT are the density and temperature gradient length scales, plays an important role in determining the island rotation velocity

Název v anglickém jazyce

A four-field gyrofluid model with neoclassical effects for the study of the rotation velocity of magnetic islands in tokamaks

Popis výsledku anglicky

A four-field system of equations which includes the neoclassical flow damping effects and the lowest-order finite-Larmor-radius (FLR) corrections is deduced from a system of gyrofluid equations. The FLR corrections to the poloidal flow damping are calculated by solving a simplified version of the gyrokinetic equation. This system of equations is applied to the study of a chain of freely rotating magnetic islands in a tokamak, resulting from the nonlinear evolution of a resistive tearing mode, to determine the island rotation velocity consistently with the fields' radial profiles close to the resonant surface. The island rotation velocity is determined by imposing the torque balance condition. The equations thus deduced are applied to the study of two different collisionality regimes, namely the weak-damping regime and the intermediate-damping regime. The equations reduce, in the weak-damping regime, to a form already obtained in previous works, while an additional term, containing the lowest order FLR corrections to the poloidal flow damping, appears in the intermediate-damping regime. The numerical integration of the final system of equations allows the determination of the dependence of the island rotation velocity on the plasma collisionality and the island width compared to the ion Larmor radius. The results show that, in the intermediate-damping regime, the island rotation velocity is almost completely determined by the neoclassical effects, with the island width playing a minor role. The parameter η i = L n / L T, where Ln and LT are the density and temperature gradient length scales, plays an important role in determining the island rotation velocity

Druh

J_imp - Článek v periodiku v databázi Web of Science

CEP obor

—

OECD FORD obor

10305 - Fluids and plasma physics (including surface physics)

Projekt

Výsledek vznikl pri realizaci vícero projektů. Více informací v záložce Projekty.

Návaznosti

I - Institucionalni podpora na dlouhodoby koncepcni rozvoj vyzkumne organizace

Rok uplatnění

2018

Kód důvěrnosti údajů

S - Úplné a pravdivé údaje o projektu nepodléhají ochraně podle zvláštních právních předpisů

Název periodika

Physics of Plasmas

ISSN

1070-664X

e-ISSN

—

Svazek periodika

25

Číslo periodika v rámci svazku

8

Stát vydavatele periodika

US - Spojené státy americké

Počet stran výsledku

14

Strana od-do

—

Kód UT WoS článku

000443730900055

EID výsledku v databázi Scopus

2-s2.0-85052586364