Enhancement of the FIDA diagnostic at ASDEX Upgrade for velocity space tomography

M. Weiland, B. Geiger, Asger Schou Jacobsen, M. Reich, Mirko Salewski, T. Odstrčil

Research output: Contribution to journalJournal articleResearchpeer-review

Abstract

Recent upgrades to the FIDA (fast-ion D-alpha) diagnostic at ASDEX Upgrade are discussed. The diagnostic has been extended from three to five line of sight arrays with different angles to the magnetic field, and a spectrometer redesign allows the simultaneous measurement of red- and blue-shifted parts of the Doppler spectrum. These improvements make it possible to reconstruct the 2D fast-ion velocity distribution from the FIDA measurements by tomographic inversion under a wide range of plasma parameters. Two applications of the tomography are presented: a comparison between the distributions resulting from 60 keV and 93 keV neutral beam injection and a velocity-space resolved study of fast-ion redistribution induced by a sawtooth crash inside and outside the sawtooth inversion radius.
Original languageEnglish
Article number025012
JournalPlasma Physics and Controlled Fusion
Volume58
Issue number2
Number of pages13
ISSN0741-3335
DOIs
Publication statusPublished - 2016

Keywords

  • Tomography
  • Sawtooth
  • Crash
  • Transport
  • Doppler
  • Spectroscopy

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