On conditioning: Reduction of secondary- and rf-field emission by electron, photon, or helium impact

rf conditioning is a well known procedure by which the electron emission in rf cavities is reduced, thereby permitting the attainment of higher field strengths. The reduction of electron emission in rf conditioning is explained by electron, photon, or He impact, which causes hydrocarbon adsorption and dehydrogenation and polymerization of adsorbed hydrocarbons. These newly formed radiation-resistant compounds show strong inelastic scattering for slow electrons, which greatly reduces the secondary emission and field emission out of excited states (rf-field emission).