Abstract

In this work, a simple method for experimentally obtaining the value of the <i>damping parameter</i> or <i>a</i>-parameter of the spectral lines emitted by an argon plasma generated at atmospheric pressure is presented. The value of this coefficient indicates the proportion existing between the Lorentzian and Doppler components of the total line profile, which can be approximated to a Voigt function for our experimental conditions. The <i>a</i>-parameter values found were within the value interval recorded in the literature. The results obtained showed that the <i>damping coefficient</i> of the lines next to the fundamental level remains practically constant along the plasma column, whereas for the spectral lines involving high-lying levels, the <i>a</i>-parameter is sensitive to the changes in the electron density in the plasma. In this work it is also proved that the self-absorption phenomenon induces errors in the calculation of <i>a</i>, due to an increase in the broadening of the line profile produced by this phenomenon.

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Douglas S. Baer, H. Andrew Chang, and Ronald K. Hanson
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Influence of self-absorption on plasma diagnostics by emission spectral lines

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Determination of pressure and temperature of gases by parameter fitting the FFT of an absorption line

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Intensity and Damping Dependence of Various Parameters Describing Spectral-Line Shapes*

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J. Opt. Soc. Am. 49(6) 609-618 (1959)