Speaker
Dr
Leo Matsuoka
(Hiroshima university)
Description
The narrow Lorentzian spectrum is obtained by using saturated absorption spectroscopy in the atomic ensemble without strong collisions. In the plasma with strong collisions, on the other hand, the saturated absorption spectrum is partially or fully broadened to the Gaussian shape whose width is the same order as the Doppler broadening. In the argon arcjet plasma, as a plasma which exhibits intermediate pressure region, the variety of saturated absorption spectra can be observed by tuning the pressure in the discharge section. In particular, spectrum with inverted pedestal which has not been previously reported was obtained. We performed a numerical analysis to validate the shape of the spectrum observed by numerically solving the two-state rate equation system under an assumption of strong velocity-changing collisions. The shape of the spectrum with inverted pedestal was reproduced by assuming the collisional frequency is significantly different for each electronic state. We also discuss the perspective of the saturated absorption spectroscopy as a tool for measuring the spatially-resolved collision parameters in the plasma.
Primary authors
Dr
Leo Matsuoka
(Hiroshima university)
Mr
Nishiya Noritaka
(Hiroshima university)
Co-authors
Mr
Kenta Yuki
(Hiroshima university)
Mr
Yutaro Sonoyama
(Hiroshima university)
