Abstract
Using the methods developed for 'interface' or 'transition-zone' dosimetry, expressions have been evaluated that give the fraction of energy escaping from small volumes containing uniform distributions of monoenergetic electron sources. Expressions are given for planar, cylindrical and spherical geometries. As an illustration of the method of calculation the energy absorbed in tissue-equivalent spheres uniformly loaded with 3H, 125I, 14C and 35S is presented.