Spatially resolved determination of the electronic density and temperature by a visible spectro-tomography diagnostic in a linear magnetized plasma

Abstract

In this work, a non-intrusive, spatially resolved, spectro-tomographic optical diagnostic of the electronic density and temperature on the linear plasma column Mistral is presented. Coupling of spectroscopy and tomography technique gives access to the local plasma light emission at different wavelengths (visible and near IR) in an argon plasma. Taking advantage of the symmetry of the Mistral experiment, the diagnostic results are validated and the plasma is found to correspond to a corona equilibrium state. With the use of another spectrometer and a Langmuir probe, we propose a non-intrusive method to determine the electronic density and temperature of each pixel of the tomographic images of the plasma. The obtained results are in good agreement with the Langmuir probe ones.Spectro-tomography combines the advantage of these two approaches to simultaneously offer spatial and spectral resolution. This method provides 2D maps of light intensities at different wavelengths [12], giving access to the plasma electronic density and temperature.The experimental set-up and the tomographic method are presented in section 2 and 3, respectively. The experimental results are detailed in section 4 with 3 sub-sections: Experimental confirmation of the corona equilibrium in Mistral,  Validation of the spectro-tomographic results,

Rotating spokes, potential hump and modulated ionization in radio frequency magnetron discharges

“…other typical E × B plasmas, such as Hall thrusters [9][10][11][12][13] and Penning discharges [14][15][16][17]. The spoke significantly affects the dynamics of electrons and ions and its fundamental understanding is hereby of importance in the operation and control of these E × B plasma based applications [15,[18][19][20][21][22][23][24][25][26][27].…”

Review of plasma turbulence experiments

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High-speed imaging of magnetized plasmas: when electron temperature matters

“…In the latter examples, the light intensity is usually considered as a proxy for the ion saturation current, or for the density, with correlations up to 0.75 26 . In low temperature and weakly ionized plasma, this approximation is usually by the Corona model [27][28][29] which assumes that the main source for photons emission is radiative decay from excited states that are populated by electronic collisions from the ground state. As a consequence the intensity of the light emitted by the radiative decay from the electronic level p to level k of a species α satisfies:…”