Flux of parallel flow momentum by parallel shear flow driven instability

Yusuke Kosuga, Sanae I. Itoh, Kimitaka Itoh

Research output: Contribution to journalArticle

3 Citations (Scopus)

Abstract

The flux of parallel momentum by parallel shear flow driven instability is calculated with the self-consistent mode dispersion. The result indicates that the diffusive component has two characteristic terms: vD1 ~ v˜x2/γ(0) and vD2 ~ v˜x2/(k||2 D||) where v˜x is the fluctuation radial velocity, γ(0) is the growth rate of the mode, k|| is the parallel wave number, and D|| is the electron diffusivity along the magnetic field. vD1 results when the parallel flow shear is above the threshold, while vD2 is important around the marginal state. Since typically vD1 ≫ vD2 ~ Dn, where Dn is the particle diffusivity, the Prandtl number (≡ v/Dn) becomes large when parallel flow shear driven instability occurs. This feature may explain the experimental observation on the difference between profiles of density and toroidal flow in edge and SOL plasmas.

Original languageEnglish
Article number1203018
JournalPlasma and Fusion Research
Volume11
DOIs
Publication statusPublished - Jan 1 2016

Fingerprint

parallel flow
shear flow
diffusivity
shear
momentum
Prandtl number
radial velocity
thresholds
profiles
magnetic fields
electrons

All Science Journal Classification (ASJC) codes

  • Condensed Matter Physics

Cite this

Flux of parallel flow momentum by parallel shear flow driven instability. / Kosuga, Yusuke; Itoh, Sanae I.; Itoh, Kimitaka.

In: Plasma and Fusion Research, Vol. 11, 1203018, 01.01.2016.

Research output: Contribution to journalArticle

@article{acdca550737f447699d9cded265ab37a,
title = "Flux of parallel flow momentum by parallel shear flow driven instability",
abstract = "The flux of parallel momentum by parallel shear flow driven instability is calculated with the self-consistent mode dispersion. The result indicates that the diffusive component has two characteristic terms: vD1 ~ v˜x2/γ(0) and vD2 ~ v˜x2/(k||2 D||) where v˜x is the fluctuation radial velocity, γ(0) is the growth rate of the mode, k|| is the parallel wave number, and D|| is the electron diffusivity along the magnetic field. vD1 results when the parallel flow shear is above the threshold, while vD2 is important around the marginal state. Since typically vD1 ≫ vD2 ~ Dn, where Dn is the particle diffusivity, the Prandtl number (≡ v/Dn) becomes large when parallel flow shear driven instability occurs. This feature may explain the experimental observation on the difference between profiles of density and toroidal flow in edge and SOL plasmas.",
author = "Yusuke Kosuga and Itoh, {Sanae I.} and Kimitaka Itoh",
year = "2016",
month = "1",
day = "1",
doi = "10.1585/pfr.11.1203018",
language = "English",
volume = "11",
journal = "Plasma and Fusion Research",
issn = "1880-6821",
publisher = "The Japan Society of Plasma Science and Nuclear Fusion Research (JSPF)",

}

TY - JOUR

T1 - Flux of parallel flow momentum by parallel shear flow driven instability

AU - Kosuga, Yusuke

AU - Itoh, Sanae I.

AU - Itoh, Kimitaka

PY - 2016/1/1

Y1 - 2016/1/1

N2 - The flux of parallel momentum by parallel shear flow driven instability is calculated with the self-consistent mode dispersion. The result indicates that the diffusive component has two characteristic terms: vD1 ~ v˜x2/γ(0) and vD2 ~ v˜x2/(k||2 D||) where v˜x is the fluctuation radial velocity, γ(0) is the growth rate of the mode, k|| is the parallel wave number, and D|| is the electron diffusivity along the magnetic field. vD1 results when the parallel flow shear is above the threshold, while vD2 is important around the marginal state. Since typically vD1 ≫ vD2 ~ Dn, where Dn is the particle diffusivity, the Prandtl number (≡ v/Dn) becomes large when parallel flow shear driven instability occurs. This feature may explain the experimental observation on the difference between profiles of density and toroidal flow in edge and SOL plasmas.

AB - The flux of parallel momentum by parallel shear flow driven instability is calculated with the self-consistent mode dispersion. The result indicates that the diffusive component has two characteristic terms: vD1 ~ v˜x2/γ(0) and vD2 ~ v˜x2/(k||2 D||) where v˜x is the fluctuation radial velocity, γ(0) is the growth rate of the mode, k|| is the parallel wave number, and D|| is the electron diffusivity along the magnetic field. vD1 results when the parallel flow shear is above the threshold, while vD2 is important around the marginal state. Since typically vD1 ≫ vD2 ~ Dn, where Dn is the particle diffusivity, the Prandtl number (≡ v/Dn) becomes large when parallel flow shear driven instability occurs. This feature may explain the experimental observation on the difference between profiles of density and toroidal flow in edge and SOL plasmas.

UR - http://www.scopus.com/inward/record.url?scp=84983510892&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=84983510892&partnerID=8YFLogxK

U2 - 10.1585/pfr.11.1203018

DO - 10.1585/pfr.11.1203018

M3 - Article

AN - SCOPUS:84983510892

VL - 11

JO - Plasma and Fusion Research

JF - Plasma and Fusion Research

SN - 1880-6821

M1 - 1203018

ER -