### 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: v_{D1} ~ v˜_{x}^{2}/γ(0) and v_{D2} ~ v˜_{x}^{2}/(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 v_{D2} is important around the marginal state. Since typically v_{D1} ≫ v_{D2} ~ D_{n}, where Dn is the particle diffusivity, the Prandtl number (≡ v/D_{n}) 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 language | English |
---|---|

Article number | 1203018 |

Journal | Plasma and Fusion Research |

Volume | 11 |

DOIs | |

Publication status | Published - Jan 1 2016 |

### Fingerprint

### All Science Journal Classification (ASJC) codes

- Condensed Matter Physics

### Cite this

*Plasma and Fusion Research*,

*11*, [1203018]. https://doi.org/10.1585/pfr.11.1203018

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

Research output: Contribution to journal › Article

*Plasma and Fusion Research*, vol. 11, 1203018. https://doi.org/10.1585/pfr.11.1203018

}

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 -