Influence of the inelastic electron-phonon scattering on the superconducting surface resistance

Experimental investigations of the rf losses in superconductors show deviations from the predictions of the weak-coupling theory. In order to explain the observations one has to take into account a number of mechanisms neglected in the weak coupling theory. One of these is the finite lifetime of the electrons due to their interaction with thermally excited phonons described by the strong-coupling theory. We have developed a computer program which calculates the surface impedance of strong-coupling superconductors at finite temperatures. In this paper the main features of the program and numerical calculations of the surface resistance of Sn, Pb, Nb and amorphous Ga are presented.