Absorption and Emission Characteristics of Diffuse Spherical Enclosures

An analysis was made to determine the energy absorbed when radiation from an external source enters a spherical cavity with diffusely reflecting walls. It was found that both the overall energy absorbed in the cavity and the local distribution of absorbed energy could be expressed in terms of simple algebraic equations that are valid for any arbitrary spatial and directional distribution of the incoming radiation. In addition, the characteristics of an isothermal spherical cavity as a possible source of near black-body radiation were investigated. This information was also expressed by simple algebraic relations.