A power-balance model of the density limit in fusion plasmas: application to the L-mode tokamak

Paolo Zanca, JET Contributors, Tommy Ahlgren

Research output: Contribution to journalArticleScientificpeer-review

Abstract

A power-balance model, with radiation losses from impurities and neutrals, gives a unified description of the density limit (DL) of the stellarator, the L-mode tokamak, and the reversed field pinch (RFP). The model predicts a Sudo-like scaling for the stellarator, a Greenwald- like scaling, alpha I-p(8/9), for the RFP and the ohmic tokamak, a mixed scaling, alpha (PIp4/9)-I-4/9, for the additionally heated L-mode tokamak. In a previous paper (Zanca et al 2017 Nucl. Fusion 57 056010) the model was compared with ohmic tokamak, RFP and stellarator experiments. Here, we address the issue of the DL dependence on heating power in the L-mode tokamak. Experimental data from high-density disrupted L-mode discharges performed at JET, as well as in other machines, arc taken as a term of comparison. The model fits the observed maximum densities better than the pure Greenwald limit.

Original languageEnglish
Article number126011
JournalNuclear Fusion
Volume59
Issue number12
Number of pages18
ISSN0029-5515
DOIs
Publication statusPublished - Dec 2019
MoE publication typeA1 Journal article-refereed

Fields of Science

  • CONFINEMENT
  • OPERATION
  • magnetohydrodynamics
  • radiation
  • transport
  • 114 Physical sciences

Cite this

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title = "A power-balance model of the density limit in fusion plasmas: application to the L-mode tokamak",
abstract = "A power-balance model, with radiation losses from impurities and neutrals, gives a unified description of the density limit (DL) of the stellarator, the L-mode tokamak, and the reversed field pinch (RFP). The model predicts a Sudo-like scaling for the stellarator, a Greenwald- like scaling, alpha I-p(8/9), for the RFP and the ohmic tokamak, a mixed scaling, alpha (PIp4/9)-I-4/9, for the additionally heated L-mode tokamak. In a previous paper (Zanca et al 2017 Nucl. Fusion 57 056010) the model was compared with ohmic tokamak, RFP and stellarator experiments. Here, we address the issue of the DL dependence on heating power in the L-mode tokamak. Experimental data from high-density disrupted L-mode discharges performed at JET, as well as in other machines, arc taken as a term of comparison. The model fits the observed maximum densities better than the pure Greenwald limit.",
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author = "Paolo Zanca and {JET Contributors} and Tommy Ahlgren",
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language = "English",
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A power-balance model of the density limit in fusion plasmas : application to the L-mode tokamak. / Zanca, Paolo; JET Contributors ; Ahlgren, Tommy.

In: Nuclear Fusion, Vol. 59, No. 12, 126011, 12.2019.

Research output: Contribution to journalArticleScientificpeer-review

TY - JOUR

T1 - A power-balance model of the density limit in fusion plasmas

T2 - application to the L-mode tokamak

AU - Zanca, Paolo

AU - JET Contributors

AU - Ahlgren, Tommy

PY - 2019/12

Y1 - 2019/12

N2 - A power-balance model, with radiation losses from impurities and neutrals, gives a unified description of the density limit (DL) of the stellarator, the L-mode tokamak, and the reversed field pinch (RFP). The model predicts a Sudo-like scaling for the stellarator, a Greenwald- like scaling, alpha I-p(8/9), for the RFP and the ohmic tokamak, a mixed scaling, alpha (PIp4/9)-I-4/9, for the additionally heated L-mode tokamak. In a previous paper (Zanca et al 2017 Nucl. Fusion 57 056010) the model was compared with ohmic tokamak, RFP and stellarator experiments. Here, we address the issue of the DL dependence on heating power in the L-mode tokamak. Experimental data from high-density disrupted L-mode discharges performed at JET, as well as in other machines, arc taken as a term of comparison. The model fits the observed maximum densities better than the pure Greenwald limit.

AB - A power-balance model, with radiation losses from impurities and neutrals, gives a unified description of the density limit (DL) of the stellarator, the L-mode tokamak, and the reversed field pinch (RFP). The model predicts a Sudo-like scaling for the stellarator, a Greenwald- like scaling, alpha I-p(8/9), for the RFP and the ohmic tokamak, a mixed scaling, alpha (PIp4/9)-I-4/9, for the additionally heated L-mode tokamak. In a previous paper (Zanca et al 2017 Nucl. Fusion 57 056010) the model was compared with ohmic tokamak, RFP and stellarator experiments. Here, we address the issue of the DL dependence on heating power in the L-mode tokamak. Experimental data from high-density disrupted L-mode discharges performed at JET, as well as in other machines, arc taken as a term of comparison. The model fits the observed maximum densities better than the pure Greenwald limit.

KW - CONFINEMENT

KW - OPERATION

KW - magnetohydrodynamics

KW - radiation

KW - transport

KW - 114 Physical sciences

U2 - 10.1088/1741-4326/ab3b31

DO - 10.1088/1741-4326/ab3b31

M3 - Article

VL - 59

JO - Nuclear Fusion

JF - Nuclear Fusion

SN - 0029-5515

IS - 12

M1 - 126011

ER -