Improvement of the Laser Phase Contrast Method for Measuring the Spatial Distribution of Electron Density Fluctuations in Heliotron E

Autor: Kado, Shinichiro, Irie, Tsutomu, Muraoka, Katsunori, Matsuo, Keiji, Tanaka, Kenji, Kondo, Katsumi, Sano, Fumimichi, Obiki, Tokuhiro
Zdroj: Japanese Journal of Applied Physics; December 1995, Vol. 34 Issue: 12 p6492-6492, 1p
Abstrakt: The laser phase contrast method is suitable for measuring long wavelength fluctuations propagating perpendicular to the laser beam axis. The obtainable data, which have so far been integrated along line-of-sights, are improved to be spatially resolved along the beam axis by selecting a particular direction of the sheared magnetic field of a toroidal confinement system utilizing a slit attached to a phase plate. First, the spatial resolution was formulated, and its validity was examined using an ultrasonic wave which simulated density fluctuations in plasmas. Then, the method was applied to plasma discharges in the Heliotron E device, and wavenumber (K)-frequency (f=?/2?) spectra, S(K, f), shows that the spatial regions were surely resolved.
Databáze: Supplemental Index