A Toroidal Harmonic Representation of the Yukawa-potential Kernel for a Circular Cylindrical Source

A true cylindrical series expansion of the Yukawa- or screened Coulomb-potential kernel is developed for a flnite circular cylindrical source through the application of a toroidal harmonic expansion. The Yukawa kernel is separated into a singular and nonsingular part. The singular part is expanded in terms of the associated toroidal harmonics and the nonsingular part is expanded in terms of an elementary binomial expansion.