Plasma and Fusion Research

Volume 20, 1401028 (2025)

Regular Articles

Quantitative Analysis of Doppler-Free Spectra via the Collisional-Radiative Model
Joseph John SIMONS1), Motoshi GOTO1,2), Tomoko KAWATE1,2), Shusuke NISHIYAMA3)
1)
Graduate University for Advanced Studies, SOKENDAI, Toki 509-5292, Japan
2)
National Institute for Fusion Science, National Institutes of Natural Sciences, Toki 509-5292, Japan
3)
Japan Healthcare University, Sapporo 062-0023, Japan
(Received 26 August 2024 / Accepted 19 March 2025 / Published 13 August 2025)

Abstract

We have constructed a simulation model of the Doppler free spectra for the hydrogen Balmer α line. We are introducing the laser excitation process into the collisional-radiative model of hydrogen atoms to see how much saturation can be achieved under realistic plasma conditions and laser power density. Results show that the simulated spectra were able to successfully model Lamb dips and peaks utilizing this method, with the simulated plasma and laser parameters showing good agreement to the ones used in the experiment. This model has additionally helped illustrate further insight into how plasma parameters can affect the spectral characteristics of Lamb dips and peaks.

Keywords

saturated absorption spectroscopy, Doppler-free, collisional-radiative model, Lamb dip, Balmer alpha, fine structure

DOI: 10.1585/pfr.20.1401028

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