Funaba H, Yasuhara R, Uehara H, Yamada I, Sakamoto R, Osakabe M, Den Hartog DJ. Electron temperature and density measurement by Thomson scattering with a high repetition rate laser of 20 kHz on LHD.
Sci Rep 2022;
12:15112. [PMID:
36068266 PMCID:
PMC9448754 DOI:
10.1038/s41598-022-19328-9]
[Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/14/2022] [Accepted: 08/29/2022] [Indexed: 11/30/2022] Open
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 [Formula: see text]s. After Raman scattering calibration, electron density profiles were derived. Fast changes in the electron temperature and density profiles within 1 ms were observed.
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