Argon injection in FT tokamak plasma

Abstract

H-like argon line spectra have been recorded by means of a high-resolution crystal spectrometer, following puff injection during a tokamak discharge, in a small range of temperature and density plasma conditions ( T e ≅ 1.2 keV, n e ≅ 10 14 cm −3). Accurate wavelengths determination shows good agreement with theoretical predictions. Second order diffraction of He-like iron, occurring at the same Bragg angle, permits an interesting wavelength comparison. Argon line intensities have been computed, in order to determine both the Lyα 2 Lyα 1 and the dielectronic satellite to resonance line ratios, the former showing a small increase over the usual 0.5 value towards the end of the discharge and the latter allowing the calculation of a plasma electron temperature in fairly good agreement with Thomson scattering measurements. Finally, the plasma ion temperature is deduced by Doppler broadening of the resonance lines.