Open AccessInterpretation of Stark broadening measurements on a spatially integrated plasma spectral line
Author(s) -
Julien Thouin,
Malyk Benmouffok,
Pierre Freton,
JeanJacques Gonzalez
Publication year - 2022
Publication title -
epj. applied physics/the european physical journal. applied physics
Language(s) - English
Resource type - Journals
eISSN - 1286-0050
pISSN - 1286-0042
DOI - 10.1051/epjap/2022220008
Subject(s) - stark effect , electron density , plasma , doppler broadening , electron temperature , atomic physics , spectral line , plasma diagnostics , spectroscopy , electron , line (geometry) , chemistry , computational physics , physics , quantum mechanics , astronomy , geometry , mathematics
In thermal plasma spectroscopy, Stark broadening measurement of hydrogenspectral lines is considered to be a good and reliable measurement for electrondensity. Unlike intensity based measurements, Stark broadening measurements canpose a problem of interpretation when the light collected is the result of aspatial integration. Indeed, when assuming no self-absorption of the emissionlines, intensities simply add up but broadenings do not. In order to betterunderstand the results of Stark broadening measurements on our thermal plasmawhich has an unneglectable thickness, a Python code has been developed based onlocal thermodynamic equilibrium (LTE) assumption and calculated plasmacomposition and properties. This code generates a simulated pseudo experimental(PE) H$\alpha$ spectral line resulting from an integration over the plasmathickness in a selected direction for a given temperature profile. The electrondensity was obtained using the Stark broadening of the PE spectral line fordifferent temperature profiles. It resulted that this measurement is governedby the maximum electron density profile up until the temperature maximumexceeds that of the maximum electron density. The electron density obtained bybroadening measurement is 70% to 80% of the maximum electron density.