Measurements of the diffusion coefficients of atomic bromine in rare gases

Abstract

The laser-photolysis-recombination-luminescence-detection method was employed to measure the diffusion coefficients of Br–rare-gas systems. The measured values are DBr–He=0.66 ±0.11, DBr–Ne=0.25±0.04, DBr–Ar=0.16±0.03, DBr–Kr=0.12±0.02, and DBr–Xe =0.086±0.015 cm2/s, respectively, at 1 atm and 300 K. Also, the diffusion coefficient of Br–Br2 was measured to be 0.065±0.011 cm2/s. A comparison was made with the results calculated from the potential curves obtained by the crossed molecular beam experiments for the Br–Ar, Br–Kr, and Br–Xe systems, and with the datum of Br–Ar measured by the time resolved–mass spectrometry. The extent of the similarity of the diffusion constants between the Kr–rare-gas systems and the Br–rare-gas systems was discussed over the temperature range of 250K to 1050 K.