The effects of titanium films on secondary electron emission phenomena in resonant cavities and at dielectric surfaces

The phenomenon of electron bombardment heating of insulators in vacuum under the influence of RF fields by several types of multipactor processes is reviewed. Evidence is given to show that a practical way of limiting the electron bombardment of insulators is to provide surfaces which have a maximum secondary electron emission yield of less than one on both the insulator and on the related metal surfaces. Thin films of titanium metal are shown to have a very good effect on suppressing the secondary electron multiplication processes at both the metal and dielectric. The discontinuous nature of very thin metal films makes it possible to coat dielectrics with titanium with thicknesses sufficient to reduce the secondary emission yield without adding significantly to the loss factor or to the dc conductivity.