New materials and technology for suppression of RF multipactor

Emphasis was on development and testing of microwave window coating materials and technology used to suppress multipactor. Windows were fabricated from Al₂O₃ ceramic. Coating materials tested included Cr₂O₃ oxides of titanium and TiN. The latter material was discovered and evaluated during this program, and was found to have excellent multipactor suppression properties. Also, a new vacuum coating procedure featuring crossed field diode array sputtering, was developed and successfully used to coat a number of windows including high power disk shaped S-band and cylindrically shaped UHF klystron windows. Performance of S-band windows both before and after high temperature vacuum bakeout is given. Calorimetrics were used to quantify performance of windows when tested in a high power microwave storage ring.