Reflection of narrow light beams by a dissipating medium

The brightness distribution of multiple back-scattering of radiation is investigated in a plane perpendicular to the beam axis as a function of the density of the artificial mists and smokes. The range of the distances from the beam axis (base) investigated was 0.02–1 m or 10^–4–1.8 in optical quantities. The investigations were accompanied by parallel measurements of the scattering index by using a turbidimeter, which permitted making quantitative estimates of the influence of the form of the index on the magnitude of the intensity of the multiply-scattered radiation for diverse values of the optical base. It is shown that the brightness distribution of the multiply scattered radiation takes on a smoother shape as the elongation of the index increases.Translated from Izvestiya Vysshikh Uchebnykh Zavedenii, Fizika, No. 11, pp. 61–65, November, 1973.