Determination of electron density fluctuation correlation functions via beam emission spectroscopy

S. Zoletnik, S. Fiedler, G. Kocsis, G. K. McCormick, J. Schweinzer, H. P. Winter

Research output: Contribution to journalArticle

37 Citations (Scopus)

Abstract

Measurement of electron density fluctuations in magnetically confined fusion plasmas by the beam emission spectroscopy (BES) method is discussed and an algorithm is given for the correct reconstruction of correlation functions of the electron density fluctuation from measured correlation functions of beam light fluctuations. The technique is generally applicable to all kinds of neutral beams, provided an appropriate model for beam light emission is available and the beam penetration time through the observation volume is shorter than the characteristic times of the plasma turbulence. Light from a 48 keV Lithium beam on W7-AS plasmas is analysed in detail, whereby electron density fluctuations in the scrape-off layer and in the edge plasma are analysed for a low-density electron cyclotron resonance heated (ECRH) heated discharge. Characteristic changes in the autocorrelation function are found at the last closed flux surface. Limitations of the technique are discussed.

Original languageEnglish
Pages (from-to)1399-1416
Number of pages18
JournalPlasma Physics and Controlled Fusion
Volume40
Issue number7
DOIs
Publication statusPublished - 1998

Fingerprint

Emission spectroscopy
Carrier concentration
spectroscopy
plasma turbulence
Plasmas
neutral beams
electron cyclotron resonance
light beams
autocorrelation
light emission
Plasma turbulence
penetration
lithium
fusion
Electron cyclotron resonance
Light emission
Autocorrelation
Lithium
Fusion reactions
Fluxes

ASJC Scopus subject areas

  • Physics and Astronomy(all)
  • Condensed Matter Physics
  • Nuclear and High Energy Physics

Cite this

Determination of electron density fluctuation correlation functions via beam emission spectroscopy. / Zoletnik, S.; Fiedler, S.; Kocsis, G.; McCormick, G. K.; Schweinzer, J.; Winter, H. P.

In: Plasma Physics and Controlled Fusion, Vol. 40, No. 7, 1998, p. 1399-1416.

Research output: Contribution to journalArticle

Zoletnik, S. ; Fiedler, S. ; Kocsis, G. ; McCormick, G. K. ; Schweinzer, J. ; Winter, H. P. / Determination of electron density fluctuation correlation functions via beam emission spectroscopy. In: Plasma Physics and Controlled Fusion. 1998 ; Vol. 40, No. 7. pp. 1399-1416.
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