OPTICAL-PROPERTIES OF AGGLOMERATED ACETYLENE SMOKE PARTICLES AT 0.5145-MU M AND 10.6-MU M WAVELENGTHS

Optical extinction measurements of acetylene smoke in a 1. 8-m tube at wavelengths of 0. 5145 and 10. 6 mu m yield specific extinction coefficients A//E of 9. 8 plus or minus 0. 8 and 0. 94 plus or minus 0. 1 m**2g** minus **1, respectively. The Mie theory applied to unagglomerated small carbon spheres can simulate the optical properties of acetylene smoke in the visible region but underestimates the specific extinction at 10. 6 mu m by at least a factor of 2. Both the visible and infrared experimental data are consistent with a model in which agglomeration of the smoke particles enhances the infrared extinction over that from small individual spheres.