Model analysis of edge relaxation phenomena in tokamak plasmas

S. Matsukawa, Sanae Itoh, M. Yagi

Research output: Contribution to journalArticle

Abstract

Based on a transition transport model with hysteresis nature, the heat transport in the plasma edge region is investigated. A hysteresis type flux-force relation is incorporated into the model of local heat diffusivity. A one-dimensional heat transport equation is solved numerically for a given influx. The time evolution of the heat flux oscillation due to the nature of the hysteresis and the parameter dependences of its amplitude and frequency are examined. The oscillatory characteristics of the outflux are found to alter depending on (1) the time scale ratio of the local limit cycle period and the spatial propagation time of successive transitions (avalanche) and (2) whether the induced avalanche can reach and make the transition at the very edge of the plasma or not. Different characteristic power law relations are obtained in the parameter dependences. The critical behaviour of the transition between two transport mechanisms, i.e. the hysteresis type and the discontinuous, is analyzed and compared. The self-organized criticality like behaviour, i.e. power spectrum obeying power law, is obtained in a limiting case of the hysteresis model.

Original languageEnglish
Pages (from-to)1241-1257
Number of pages17
JournalPlasma Physics and Controlled Fusion
Volume42
Issue number12
DOIs
Publication statusPublished - Dec 1 2000

Fingerprint

Hysteresis
hysteresis
Plasmas
heat
avalanches
scale (ratio)
Power spectrum
diffusivity
power spectra
Heat flux
heat flux
Fluxes
oscillations
cycles
propagation
Hot Temperature

All Science Journal Classification (ASJC) codes

  • Nuclear Energy and Engineering
  • Condensed Matter Physics

Cite this

Model analysis of edge relaxation phenomena in tokamak plasmas. / Matsukawa, S.; Itoh, Sanae; Yagi, M.

In: Plasma Physics and Controlled Fusion, Vol. 42, No. 12, 01.12.2000, p. 1241-1257.

Research output: Contribution to journalArticle

Matsukawa, S. ; Itoh, Sanae ; Yagi, M. / Model analysis of edge relaxation phenomena in tokamak plasmas. In: Plasma Physics and Controlled Fusion. 2000 ; Vol. 42, No. 12. pp. 1241-1257.
@article{567e53a176cb4b37948dc2e6d489d26b,
title = "Model analysis of edge relaxation phenomena in tokamak plasmas",
abstract = "Based on a transition transport model with hysteresis nature, the heat transport in the plasma edge region is investigated. A hysteresis type flux-force relation is incorporated into the model of local heat diffusivity. A one-dimensional heat transport equation is solved numerically for a given influx. The time evolution of the heat flux oscillation due to the nature of the hysteresis and the parameter dependences of its amplitude and frequency are examined. The oscillatory characteristics of the outflux are found to alter depending on (1) the time scale ratio of the local limit cycle period and the spatial propagation time of successive transitions (avalanche) and (2) whether the induced avalanche can reach and make the transition at the very edge of the plasma or not. Different characteristic power law relations are obtained in the parameter dependences. The critical behaviour of the transition between two transport mechanisms, i.e. the hysteresis type and the discontinuous, is analyzed and compared. The self-organized criticality like behaviour, i.e. power spectrum obeying power law, is obtained in a limiting case of the hysteresis model.",
author = "S. Matsukawa and Sanae Itoh and M. Yagi",
year = "2000",
month = "12",
day = "1",
doi = "10.1088/0741-3335/42/12/302",
language = "English",
volume = "42",
pages = "1241--1257",
journal = "Plasma Physics and Controlled Fusion",
issn = "0741-3335",
publisher = "IOP Publishing Ltd.",
number = "12",

}

TY - JOUR

T1 - Model analysis of edge relaxation phenomena in tokamak plasmas

AU - Matsukawa, S.

AU - Itoh, Sanae

AU - Yagi, M.

PY - 2000/12/1

Y1 - 2000/12/1

N2 - Based on a transition transport model with hysteresis nature, the heat transport in the plasma edge region is investigated. A hysteresis type flux-force relation is incorporated into the model of local heat diffusivity. A one-dimensional heat transport equation is solved numerically for a given influx. The time evolution of the heat flux oscillation due to the nature of the hysteresis and the parameter dependences of its amplitude and frequency are examined. The oscillatory characteristics of the outflux are found to alter depending on (1) the time scale ratio of the local limit cycle period and the spatial propagation time of successive transitions (avalanche) and (2) whether the induced avalanche can reach and make the transition at the very edge of the plasma or not. Different characteristic power law relations are obtained in the parameter dependences. The critical behaviour of the transition between two transport mechanisms, i.e. the hysteresis type and the discontinuous, is analyzed and compared. The self-organized criticality like behaviour, i.e. power spectrum obeying power law, is obtained in a limiting case of the hysteresis model.

AB - Based on a transition transport model with hysteresis nature, the heat transport in the plasma edge region is investigated. A hysteresis type flux-force relation is incorporated into the model of local heat diffusivity. A one-dimensional heat transport equation is solved numerically for a given influx. The time evolution of the heat flux oscillation due to the nature of the hysteresis and the parameter dependences of its amplitude and frequency are examined. The oscillatory characteristics of the outflux are found to alter depending on (1) the time scale ratio of the local limit cycle period and the spatial propagation time of successive transitions (avalanche) and (2) whether the induced avalanche can reach and make the transition at the very edge of the plasma or not. Different characteristic power law relations are obtained in the parameter dependences. The critical behaviour of the transition between two transport mechanisms, i.e. the hysteresis type and the discontinuous, is analyzed and compared. The self-organized criticality like behaviour, i.e. power spectrum obeying power law, is obtained in a limiting case of the hysteresis model.

UR - http://www.scopus.com/inward/record.url?scp=0034516415&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=0034516415&partnerID=8YFLogxK

U2 - 10.1088/0741-3335/42/12/302

DO - 10.1088/0741-3335/42/12/302

M3 - Article

AN - SCOPUS:0034516415

VL - 42

SP - 1241

EP - 1257

JO - Plasma Physics and Controlled Fusion

JF - Plasma Physics and Controlled Fusion

SN - 0741-3335

IS - 12

ER -