Thomson scattering on the Large Plasma Device

Abstract

We have developed a non-collective Thomson scattering diagnostic for measurements of electron density and temperature on the Large Plasma Device. A triple grating spectrometer with a tunable notch filter is used to discriminate the faint scattering signal from the stray light. In this paper we describe the diagnostic and its calibration via Raman scattering, and present the first measurements performed with the fully commissioned system. Depending on the discharge conditions, the measured densities and temperatures range from 4.0$\times$10$^{12}$ cm$^{-3}$ to 2.8$\times$10$^{13}$ cm$^{-3}$, and from 1.2 eV to 6.8 eV, respectively. The variation of the measurement error with plasma parameters and discharges averaged is also discussed.