Although the theory of partially enclosed, cavity-type sources of radiant energy, with a few clarifications and corrections, has reached an apparent fruition, surface characteristics and practical construction problems will still limit the closeness to which these sources can he made to approach blackbodies. This paper gives results, which agree with prior published data, of a new computation for cylinders and shows the ray-trace analysis of cones to be unacceptable.
CHARLES S. WILLIAMS, "Specularly vs Diffusely Reflecting Walls for Cavity-Type Sources of Radiant Energy," J. Opt. Soc. Am. 59, 249-251 (1969)