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Title: Enhanced toroidal flow stabilization of edge localized modes with increased plasma density

Abstract

Toroidal flow alone is generally thought to have an important influence on tokamak edge pedestal stability, even though theoretical analysis often predicts merely a weak stabilizing effect of toroidal flow on the edge localized modes (ELMs) in experimental parameter regimes. For the first time, we find from two-fluid MHD calculations that such a stabilization, however, can be significantly enhanced by increasing the edge plasma density. Our finding resolves a long-standing mystery whether or how toroidal rotation can indeed have an effective influence on ELMs, and explains why the ELM mitigation and suppression by toroidal rotation are more favorably achieved in higher collisionality regime in recent experiments. Furthermore, the finding suggests a new control scheme on modulating toroidal flow stabilization of ELMs with plasma density, along with a new additional constraint on the optimal level of plasma density for the desired edge plasma conditions

Authors:
 [1]; ORCiD logo [2]; ORCiD logo [1]
  1. Univ. of Science and Technology of China, Anhui (People's Republic of China)
  2. Univ. of Science and Technology of China, Anhui (People's Republic of China); Univ. of Wisconsin-Madison, Madison, WI (United States)
Publication Date:
Research Org.:
Univ. of Wisconsin, Madison, WI (United States)
Sponsoring Org.:
USDOE
OSTI Identifier:
1474295
Alternate Identifier(s):
OSTI ID: 1377086
Grant/Contract Number:  
FG02-86ER53218; AC02-05CH11231; FC02-08ER54975
Resource Type:
Accepted Manuscript
Journal Name:
Physics of Plasmas
Additional Journal Information:
Journal Volume: 24; Journal Issue: 9; Journal ID: ISSN 1070-664X
Publisher:
American Institute of Physics (AIP)
Country of Publication:
United States
Language:
English
Subject:
70 PLASMA PHYSICS AND FUSION TECHNOLOGY

Citation Formats

Cheng, Shikui, Zhu, Ping, and Banerjee, Debabrata. Enhanced toroidal flow stabilization of edge localized modes with increased plasma density. United States: N. p., 2017. Web. doi:10.1063/1.4990978.
Cheng, Shikui, Zhu, Ping, & Banerjee, Debabrata. Enhanced toroidal flow stabilization of edge localized modes with increased plasma density. United States. doi:10.1063/1.4990978.
Cheng, Shikui, Zhu, Ping, and Banerjee, Debabrata. Mon . "Enhanced toroidal flow stabilization of edge localized modes with increased plasma density". United States. doi:10.1063/1.4990978. https://www.osti.gov/servlets/purl/1474295.
@article{osti_1474295,
title = {Enhanced toroidal flow stabilization of edge localized modes with increased plasma density},
author = {Cheng, Shikui and Zhu, Ping and Banerjee, Debabrata},
abstractNote = {Toroidal flow alone is generally thought to have an important influence on tokamak edge pedestal stability, even though theoretical analysis often predicts merely a weak stabilizing effect of toroidal flow on the edge localized modes (ELMs) in experimental parameter regimes. For the first time, we find from two-fluid MHD calculations that such a stabilization, however, can be significantly enhanced by increasing the edge plasma density. Our finding resolves a long-standing mystery whether or how toroidal rotation can indeed have an effective influence on ELMs, and explains why the ELM mitigation and suppression by toroidal rotation are more favorably achieved in higher collisionality regime in recent experiments. Furthermore, the finding suggests a new control scheme on modulating toroidal flow stabilization of ELMs with plasma density, along with a new additional constraint on the optimal level of plasma density for the desired edge plasma conditions},
doi = {10.1063/1.4990978},
journal = {Physics of Plasmas},
number = 9,
volume = 24,
place = {United States},
year = {2017},
month = {8}
}

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