The particle density of ground-state chromium atoms within one cross section of an arc plasma was measured spatially resolved, and the spatial distribution of the line shape of the chromium resonance line at 427.48 nm was partly determined. The measurements were performed with a newly developed setup that combines the methods of resonance interferometry and refractive tomography. The wavelength of a dye laser was scanned over the investigated transition, and the refractive index was measured spatially and spectrally resolved by use of tomography. For each spatial point the particle density and the local line shape were calculated from the measured spectral refractivity distribution by the method of resonance interferometry. We describe the physical principles, the optical arrangement, and the numerical apparatus, and we discuss the results and further possibilities.
© 1997 Optical Society of America
Georg Pretzler, Christian Haas, Theo Neger, and Helmut Jäger, "Spatially resolved determination of atomic particle densities and line shapes within an arc plasma by tomographic resonance interferometry," Appl. Opt. 36, 8806-8814 (1997)