Development of Ceramic Vacuum Chambers and Their Impedance Measurement

Several technical schemes of constructing a injection kicker magnet and its vacuum chambers are firstly reviewed and discussed. A method of using ferrite kicker magnets with ceramic chambers inside is adopted in HLS new injection system. The inner surfaces of these ceramic chambers are coated with a metallic layer to meet the requirements of both the penetration of pulse magnetic field and small beam coupling impedance. The loss factors and wake fields of the ceramic chambers with and without coating are measured. Broadband impedance parameters of these ceramic chambers are obtained by fitting the measured data. Combining the results of magnetic field studies, an improved coating scheme is proposed for the new ceramic chambers.