Broadening and shift of neutral chromium absorption lines by various perturbing gases

Abstract

The broadening and shift of the absorption lines ( a 7 S- z 7 P°, a 7 S- y 7 P° and a 5 S- z 5 P°) of the neutral chromium atom were observed at various temperatures (1500–1800 K) and densities (0.24-3.2x 10 19/cm 3) of foreign perturbers (He, Ar, N 2, H 2). The dependence of width and shift on temperature and density was studied. The collisional broadening and shift rates were determined from the profile measurements. The results are interpreted in terms of the Lindholm-Foley interaction potential between radiating atom and perturbers. Semi-quantitative agreement of theory and experiment was found in some cases for the temperature dependence of width and shift and for the differences of attractive constants Δ C 6 between upper and lower states of chromium lines.