High frequency geodesic acoustic modes in electron scale turbulence
Artikel i vetenskaplig tidskrift, 2013

In this work the finite β-effects of an electron branch of the geodesic acoustic mode (el-GAM) driven by electron temperature gradient (ETG) modes is presented. The work is based on a fluid description of the ETG mode retaining non-adiabatic ions and the dispersion relation for el-GAMs driven non-linearly by ETG modes is derived. The ETG growth rate from the fluid model is compared with the results found from gyrokinetic simulations with good agreement. A new saturation mechanism for ETG turbulence through the interaction with el-GAMs is found, resulting in a significantly enhanced ETG turbulence saturation level compared with the mixing length estimate. It is shown that the el-GAM may be stabilized by an increase in finite β as well as by increasing non-adiabaticity. The decreased GAM growth rates is due to the inclusion of the Maxwell stress.

ETG

Transport Barriers

GAM

Zonal Flows

Författare

Johan Anderson

Chalmers, Teknisk fysik, Nukleär teknik

Andreas Skyman

Chalmers, Rymd- och geovetenskap, Plasmafysik och fusionsenergi

Hans Nordman

Chalmers, Rymd- och geovetenskap, Plasmafysik och fusionsenergi

Raghvendra Singh

Institute for Plasma Research India

WCI

P.K. Kaw

Institute for Plasma Research India

Nuclear Fusion

0029-5515 (ISSN)

Vol. 53 article nr. 123016- 123016

Ämneskategorier

Fysik

Fusion, plasma och rymdfysik

Styrkeområden

Energi

Fundament

Grundläggande vetenskaper

Infrastruktur

C3SE (Chalmers Centre for Computational Science and Engineering)

DOI

10.1088/0029-5515/53/12/123016