Semianalytical calculation of the zonal-flow oscillation frequency in stellarators

Pedro Monreal, Edilberto Sánchez, Iván Calvo, Andrés Bustos, Félix I. Parra, Alexey Mishchenko, Axel Könies, Ralf Kleiber

Research output: Contribution to journalArticlepeer-review

10 Scopus citations

Abstract

Due to their capability to reduce turbulent transport in magnetized plasmas, understanding the dynamics of zonal flows is an important problem in the fusion program. Since the pioneering work by Rosenbluth and Hinton in axisymmetric tokamaks, it is known that studying the linear and collisionless relaxation of zonal flow perturbations gives valuable information and physical insight. Recently, the problem has been investigated in stellarators and it has been found that in these devices the relaxation process exhibits a characteristic feature: a damped oscillation. The frequency of this oscillation might be a relevant parameter in the regulation of turbulent transport, and therefore its efficient and accurate calculation is important. Although an analytical expression can be derived for the frequency, its numerical evaluation is not simple and has not been exploited systematically so far. Here, a numerical method for its evaluation is considered, and the results are compared with those obtained by calculating the frequency from gyrokinetic simulations. This 'semianalytical' approach for the determination of the zonal-flow frequency is revealed to be accurate and faster than the one based on gyrokinetic simulations.

Original languageEnglish (US)
Article number065005
JournalPlasma Physics and Controlled Fusion
Volume59
Issue number6
DOIs
StatePublished - Apr 27 2017
Externally publishedYes

All Science Journal Classification (ASJC) codes

  • Nuclear Energy and Engineering
  • Condensed Matter Physics

Keywords

  • CAS3D-K
  • damped oscillation
  • frequency
  • zonal-flow

Fingerprint

Dive into the research topics of 'Semianalytical calculation of the zonal-flow oscillation frequency in stellarators'. Together they form a unique fingerprint.

Cite this