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Title: Aspect ratio effects on limited scrape-off layer plasma turbulence

Abstract

The drift-reduced Braginskii model describing turbulence in the tokamak scrape-off layer is written for a general magnetic configuration with a limiter. The equilibrium is then specified for a circular concentric magnetic geometry retaining aspect ratio effects. Simulations are then carried out with the help of the global, flux-driven fluid three-dimensional code GBS [Ricci et al., Plasma Phys. Controlled Fusion 54, 124047 (2012)]. Linearly, both simulations and simplified analytical models reveal a stabilization of ballooning modes. Nonlinearly, flux-driven nonlinear simulations give a pressure characteristic length whose trends are correctly captured by the gradient removal theory [Ricci and Rogers, Phys. Plasmas 20, 010702 (2013)], that assumes the profile flattening from the linear modes as the saturation mechanism. More specifically, the linear stabilization of ballooning modes is reflected by a 15% increase in the steady-state pressure gradient obtained from GBS nonlinear simulations when going from an infinite to a realistic aspect ratio.

Authors:
; ; ; ;  [1]
  1. École Polytechnique Fédérale de Lausanne (EPFL), Centre de Recherches en Physique des Plasmas, Association Euratom-Confédération Suisse, CH-1015 Lausanne (Switzerland)
Publication Date:
OSTI Identifier:
22252108
Resource Type:
Journal Article
Resource Relation:
Journal Name: Physics of Plasmas; Journal Volume: 21; Journal Issue: 2; Other Information: (c) 2014 AIP Publishing LLC; Country of input: International Atomic Energy Agency (IAEA)
Country of Publication:
United States
Language:
English
Subject:
70 PLASMA PHYSICS AND FUSION TECHNOLOGY; ASPECT RATIO; BALLOONING INSTABILITY; CONFIGURATION; GEOMETRY; NONLINEAR PROBLEMS; PLASMA; PLASMA SCRAPE-OFF LAYER; PRESSURE GRADIENTS; SATURATION; SIMULATION; STABILIZATION; STEADY-STATE CONDITIONS; THREE-DIMENSIONAL CALCULATIONS; TOKAMAK DEVICES; TURBULENCE

Citation Formats

Jolliet, Sébastien, E-mail: sebastien.jolliet@epfl.ch, Halpern, Federico D., Loizu, Joaquim, Mosetto, Annamaria, and Ricci, Paolo. Aspect ratio effects on limited scrape-off layer plasma turbulence. United States: N. p., 2014. Web. doi:10.1063/1.4863956.
Jolliet, Sébastien, E-mail: sebastien.jolliet@epfl.ch, Halpern, Federico D., Loizu, Joaquim, Mosetto, Annamaria, & Ricci, Paolo. Aspect ratio effects on limited scrape-off layer plasma turbulence. United States. doi:10.1063/1.4863956.
Jolliet, Sébastien, E-mail: sebastien.jolliet@epfl.ch, Halpern, Federico D., Loizu, Joaquim, Mosetto, Annamaria, and Ricci, Paolo. Sat . "Aspect ratio effects on limited scrape-off layer plasma turbulence". United States. doi:10.1063/1.4863956.
@article{osti_22252108,
title = {Aspect ratio effects on limited scrape-off layer plasma turbulence},
author = {Jolliet, Sébastien, E-mail: sebastien.jolliet@epfl.ch and Halpern, Federico D. and Loizu, Joaquim and Mosetto, Annamaria and Ricci, Paolo},
abstractNote = {The drift-reduced Braginskii model describing turbulence in the tokamak scrape-off layer is written for a general magnetic configuration with a limiter. The equilibrium is then specified for a circular concentric magnetic geometry retaining aspect ratio effects. Simulations are then carried out with the help of the global, flux-driven fluid three-dimensional code GBS [Ricci et al., Plasma Phys. Controlled Fusion 54, 124047 (2012)]. Linearly, both simulations and simplified analytical models reveal a stabilization of ballooning modes. Nonlinearly, flux-driven nonlinear simulations give a pressure characteristic length whose trends are correctly captured by the gradient removal theory [Ricci and Rogers, Phys. Plasmas 20, 010702 (2013)], that assumes the profile flattening from the linear modes as the saturation mechanism. More specifically, the linear stabilization of ballooning modes is reflected by a 15% increase in the steady-state pressure gradient obtained from GBS nonlinear simulations when going from an infinite to a realistic aspect ratio.},
doi = {10.1063/1.4863956},
journal = {Physics of Plasmas},
number = 2,
volume = 21,
place = {United States},
year = {Sat Feb 15 00:00:00 EST 2014},
month = {Sat Feb 15 00:00:00 EST 2014}
}
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