Scientific Reports (Sep 2022)

Electron temperature and density measurement by Thomson scattering with a high repetition rate laser of 20 kHz on LHD

  • H. Funaba,
  • R. Yasuhara,
  • H. Uehara,
  • I. Yamada,
  • R. Sakamoto,
  • M. Osakabe,
  • D. J. Den Hartog

DOI
https://doi.org/10.1038/s41598-022-19328-9
Journal volume & issue
Vol. 12, no. 1
pp. 1 – 10

Abstract

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Abstract Thomson scattering measurements with a high-repetition-rate laser have commenced in the Large Helical Device. As an example of the fast phenomena captured by this diagnostic system, measurements at a 20 kHz repetition-rate in hydrogen pellet-injected plasmas are presented. Signal processing methods for this measurement have been developed and electron temperature profiles with almost 70 spatial points were evaluated at time intervals of 50 $$\upmu$$ μ s. After Raman scattering calibration, electron density profiles were derived. Fast changes in the electron temperature and density profiles within 1 ms were observed.