Extreme UV spectroscopy measurements and analysis for tungsten density studies in the WEST tokamak

R. Guirlet (1) , C. Desgranges (1) , J. L. Schwob (2) , P. Mandelbaum (3) , M. Y. Boumendjel (1)

1 IRFM - Institut de Recherche sur la Fusion par confinement Magnétique
2 Racah Institute of Physics, Hebrew University of Jerusalem, Israel
3 Racah Institute of Physics - Racah Institute of Physics

The VUV emission of tungsten in WEST is measured by an absolutely calibrated grazing incidence spectrometer of the Schwob-Fraenkel type which can scan the lower half of the plasma. We have analysed the detected spectral lines in the range 120-140 Å and compared their behaviour with calculations and published information. We obtained an unambiguous identification of four intense and well resolved spectral lines emitted by W$^{42+}$-W$^{45+}$ close to the magnetic axis in the analysed experiments. The measured spectral line brightnesses are used to assess the Tungsten density in the emission region. In a case of a scanning line of sight, we investigate the possibility to calculate the Tungsten density profile from the angular brightness profiles. In a case of a fixed line of sight, we deduce from the measurements the core Tungsten density profile evolution during a radiative collapse.

Domains: Physics [physics]

R. Guirlet, C. Desgranges, J. L. Schwob, P. Mandelbaum, M. Y. Boumendjel. Extreme UV spectroscopy measurements and analysis for tungsten density studies in the WEST tokamak. Plasma Physics and Controlled Fusion, In press. ⟨cea-03623368⟩