Modelling of Density Limit Phenomena in Toroidal Helical Plasmas

Kimitaka Itoh, Sanae Itoh, Louis Giannone

Research output: Contribution to journalArticle

5 Citations (Scopus)

Abstract

The physics of density limit phenomena in toroidal helical plasmas based on an analytic point model of toroidal plasmas is discussed. The combined mechanism of the transport and radiation loss of energy is analyzed, and the achievable density is derived. A scaling law of the density limit is discussed. The dependence of the critical density on the heating power, magnetic field, plasma size and safety factor in the case of L-mode energy confinement is explained. The dynamic evolution of the plasma energy and radiation loss is discussed. Assuming a simple model of density evolution, of a sudden loss of density if the temperature becomes lower than critical value, then a limit cycle oscillation is shown to occur. A condition that divides the limit cycle oscillation and the complete radiation collapse is discussed. This model seems to explain the density limit oscillation that has been observed on the Wendelstein 7-AS (W7-AS) stellarator.

Original languageEnglish
Pages (from-to)3274-3284
Number of pages11
Journaljournal of the physical society of japan
Volume70
Issue number11
DOIs
Publication statusPublished - Nov 1 2001

Fingerprint

oscillations
radiation
safety factors
cycles
toroidal plasmas
stellarators
scaling laws
energy dissipation
physics
heating
energy
magnetic fields

All Science Journal Classification (ASJC) codes

  • Physics and Astronomy(all)

Cite this

Modelling of Density Limit Phenomena in Toroidal Helical Plasmas. / Itoh, Kimitaka; Itoh, Sanae; Giannone, Louis.

In: journal of the physical society of japan, Vol. 70, No. 11, 01.11.2001, p. 3274-3284.

Research output: Contribution to journalArticle

Itoh, Kimitaka ; Itoh, Sanae ; Giannone, Louis. / Modelling of Density Limit Phenomena in Toroidal Helical Plasmas. In: journal of the physical society of japan. 2001 ; Vol. 70, No. 11. pp. 3274-3284.
@article{6cac92ba87fa42ec8aff1f63b69cd3bc,
title = "Modelling of Density Limit Phenomena in Toroidal Helical Plasmas",
abstract = "The physics of density limit phenomena in toroidal helical plasmas based on an analytic point model of toroidal plasmas is discussed. The combined mechanism of the transport and radiation loss of energy is analyzed, and the achievable density is derived. A scaling law of the density limit is discussed. The dependence of the critical density on the heating power, magnetic field, plasma size and safety factor in the case of L-mode energy confinement is explained. The dynamic evolution of the plasma energy and radiation loss is discussed. Assuming a simple model of density evolution, of a sudden loss of density if the temperature becomes lower than critical value, then a limit cycle oscillation is shown to occur. A condition that divides the limit cycle oscillation and the complete radiation collapse is discussed. This model seems to explain the density limit oscillation that has been observed on the Wendelstein 7-AS (W7-AS) stellarator.",
author = "Kimitaka Itoh and Sanae Itoh and Louis Giannone",
year = "2001",
month = "11",
day = "1",
doi = "10.1143/JPSJ.70.3274",
language = "English",
volume = "70",
pages = "3274--3284",
journal = "Journal of the Physical Society of Japan",
issn = "0031-9015",
publisher = "Physical Society of Japan",
number = "11",

}

TY - JOUR

T1 - Modelling of Density Limit Phenomena in Toroidal Helical Plasmas

AU - Itoh, Kimitaka

AU - Itoh, Sanae

AU - Giannone, Louis

PY - 2001/11/1

Y1 - 2001/11/1

N2 - The physics of density limit phenomena in toroidal helical plasmas based on an analytic point model of toroidal plasmas is discussed. The combined mechanism of the transport and radiation loss of energy is analyzed, and the achievable density is derived. A scaling law of the density limit is discussed. The dependence of the critical density on the heating power, magnetic field, plasma size and safety factor in the case of L-mode energy confinement is explained. The dynamic evolution of the plasma energy and radiation loss is discussed. Assuming a simple model of density evolution, of a sudden loss of density if the temperature becomes lower than critical value, then a limit cycle oscillation is shown to occur. A condition that divides the limit cycle oscillation and the complete radiation collapse is discussed. This model seems to explain the density limit oscillation that has been observed on the Wendelstein 7-AS (W7-AS) stellarator.

AB - The physics of density limit phenomena in toroidal helical plasmas based on an analytic point model of toroidal plasmas is discussed. The combined mechanism of the transport and radiation loss of energy is analyzed, and the achievable density is derived. A scaling law of the density limit is discussed. The dependence of the critical density on the heating power, magnetic field, plasma size and safety factor in the case of L-mode energy confinement is explained. The dynamic evolution of the plasma energy and radiation loss is discussed. Assuming a simple model of density evolution, of a sudden loss of density if the temperature becomes lower than critical value, then a limit cycle oscillation is shown to occur. A condition that divides the limit cycle oscillation and the complete radiation collapse is discussed. This model seems to explain the density limit oscillation that has been observed on the Wendelstein 7-AS (W7-AS) stellarator.

UR - http://www.scopus.com/inward/record.url?scp=0035642938&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=0035642938&partnerID=8YFLogxK

U2 - 10.1143/JPSJ.70.3274

DO - 10.1143/JPSJ.70.3274

M3 - Article

VL - 70

SP - 3274

EP - 3284

JO - Journal of the Physical Society of Japan

JF - Journal of the Physical Society of Japan

SN - 0031-9015

IS - 11

ER -