Assessment of Experimental Errors in Time-Integrated Plasma Spectroscopy

Abstract

Application of laser beam as a light source is important in light-wave technology. Also, interaction of laser radiation with target gives valuable information about material properties. Estimation of experimental errors in plasma spectroscopy is necessary because measurements of relative and absolute intensities are always accompanied by many difficulties and sources of possible errors. Wavelength calibration and relative spectral sensitivity calibration were performed, same as instrumental profile was determined. In wavelength calibration, by using the projection densitometer and an iron spark spectrum recorded above or below the plasma spectrum on the same film, an accuracy better than 0.01 nm can be achieved what is very good in comparison with spectral line FWHM (~ 1 nm). Calibrated tungsten filament lamp was used as spectral radiance standard with errors less than 3%. The instrumental FWHM was determined at several wavelengths in the spectral range covered and for other wavelengths it was obtained by interpolation. By comparing this instrumental profile with the real FWHM of spectral lines observed in plasma, it was obvious that the instrumental profile can be neglected for wavelengths under about 400 nm