[en] The purpose of this paper is twofold: (1) to summarize highly-precise results from analytic solutions for the infinite critical cylinder, and (2) to demonstrate how these results can be applied as benchmarks in testing numerical solutions for neutral particle transport. The interest in transport solutions for multiplying media in critical, cylindrical geometry arises from the widespread occurrence of such configurations in reactor design and fuel process plant applications. With the assumption of isotropic scattering, the monoenergetic form of the neutron transport equation has been solved by various analytic techniques to obtain values of critical radii for the axially infinite cylinder. The multiplying media is characterized by the mean number of neutron secondaries per collision