Electron temperature and density measurement by Thomson scattering with a high repetition rate laser of 20 kHz on LHD
H. Funaba, Ryo Yasuhara, Hiroki Uehara, I. Yamada, R. Sakamoto, M. Osakabe, D. J. Den Hartog
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.
Topics & Concepts
Thomson scatteringElectron temperatureElectron densityLaserElectronPlasmaScatteringCalibrationRaman scatteringPlasma diagnosticsAtomic physicsMaterials sciencePhysicsOpticsRaman spectroscopyNuclear physicsQuantum mechanicsMagnetic confinement fusion researchLaser-Plasma Interactions and DiagnosticsLaser-induced spectroscopy and plasma