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Title: Collisional model of quasilinear transport driven by toroidal electrostatic ion temperature gradient modes

Abstract

The stability of ion temperature gradient (ITG) modes and the quasilinear fluxes driven by them are analyzed in weakly collisional tokamak plasmas using a semianalytical model based on an approximate solution of the gyrokinetic equation, where collisions are modeled by a Lorentz operator. Although the frequencies and growth rates of ITG modes far from threshold are only very weakly sensitive to the collisionality, the a/L{sub Ti} threshold for stability is affected significantly by electron-ion collisions. The decrease in collisionality destabilizes the ITG mode driving an inward particle flux, which leads to the steepening of the density profile. Closed analytical expressions for the electron and ion density and temperature responses have been derived without expansion in the smallness of the magnetic drift frequencies. The results have been compared with gyrokinetic simulations with GYRO and illustrated by showing the scalings of the eigenvalues and quasilinear fluxes with collisionality, temperature scale length, and magnetic shear.

Authors:
;  [1];  [2];  [3]
  1. Department of Radio and Space Science, Chalmers University of Technology, and Euratom-VR Association, SE-41296 Goeteborg (Sweden)
  2. General Atomics, P.O. Box 85608, San Diego, California 92186 (United States)
  3. EURATOM/UKAEA Fusion Association, Culham Science Centre, Abingdon, Oxon OX14 3DB (United Kingdom)
Publication Date:
OSTI Identifier:
21277299
Resource Type:
Journal Article
Journal Name:
Physics of Plasmas
Additional Journal Information:
Journal Volume: 16; Journal Issue: 7; Other Information: DOI: 10.1063/1.3168611; (c) 2009 American Institute of Physics; Country of input: International Atomic Energy Agency (IAEA); Journal ID: ISSN 1070-664X
Country of Publication:
United States
Language:
English
Subject:
70 PLASMA PHYSICS AND FUSION TECHNOLOGY; COLLISIONAL PLASMA; ELECTRON DENSITY; ELECTRON-ION COLLISIONS; ION DENSITY; ION TEMPERATURE; PLASMA SIMULATION; TEMPERATURE GRADIENTS; TOKAMAK DEVICES

Citation Formats

Pusztai, I, Fueloep, T, Candy, J, and Hastie, R J. Collisional model of quasilinear transport driven by toroidal electrostatic ion temperature gradient modes. United States: N. p., 2009. Web. doi:10.1063/1.3168611.
Pusztai, I, Fueloep, T, Candy, J, & Hastie, R J. Collisional model of quasilinear transport driven by toroidal electrostatic ion temperature gradient modes. United States. https://doi.org/10.1063/1.3168611
Pusztai, I, Fueloep, T, Candy, J, and Hastie, R J. 2009. "Collisional model of quasilinear transport driven by toroidal electrostatic ion temperature gradient modes". United States. https://doi.org/10.1063/1.3168611.
@article{osti_21277299,
title = {Collisional model of quasilinear transport driven by toroidal electrostatic ion temperature gradient modes},
author = {Pusztai, I and Fueloep, T and Candy, J and Hastie, R J},
abstractNote = {The stability of ion temperature gradient (ITG) modes and the quasilinear fluxes driven by them are analyzed in weakly collisional tokamak plasmas using a semianalytical model based on an approximate solution of the gyrokinetic equation, where collisions are modeled by a Lorentz operator. Although the frequencies and growth rates of ITG modes far from threshold are only very weakly sensitive to the collisionality, the a/L{sub Ti} threshold for stability is affected significantly by electron-ion collisions. The decrease in collisionality destabilizes the ITG mode driving an inward particle flux, which leads to the steepening of the density profile. Closed analytical expressions for the electron and ion density and temperature responses have been derived without expansion in the smallness of the magnetic drift frequencies. The results have been compared with gyrokinetic simulations with GYRO and illustrated by showing the scalings of the eigenvalues and quasilinear fluxes with collisionality, temperature scale length, and magnetic shear.},
doi = {10.1063/1.3168611},
url = {https://www.osti.gov/biblio/21277299}, journal = {Physics of Plasmas},
issn = {1070-664X},
number = 7,
volume = 16,
place = {United States},
year = {Wed Jul 15 00:00:00 EDT 2009},
month = {Wed Jul 15 00:00:00 EDT 2009}
}