Secondary electron emission measurements on materials used for superconducting microwave cavities

The secondary electron emission coefficients for Nb, Nb2O5, Nb3Sn, NbN, Ti, and TiN, materials applied in microwave superconducting cavities, have been measured as a function of primary electron energy from 200 to 2000 eV. Data for ’’clean’’, ’’oxidized’’, and ’’as-prepared’’ surfaces are presented. Companion Auger spectra show the constituents of the surface under test. The results should be helpful in improving techniques for preparation of surfaces of high-power rf cavities that suffer in performance from multipactoring.