A physical model and the near-field characteristics of a multipole

The physical multipole is conceived as a small sphere with a certain normal velocity distribution on its surface S that coincides with the field of a mathematical (point) multipole outside S. The near-field characteristics, such as the complex radiated power, impedance, and attached mass, are calculated by taking integrals over S for the leading multipoles. A number of new results have been obtained. In particular, the functional completeness of multipole fields has been proven. fi has been demonstrated that the field of an arbitrary quadrupole is a sum of two simple independent quadrupoles-longitudinal and transversal.