RF bypass on the proton synchrotron vacuum chamber flanges

RF-bypass circuits, consisting of resistors and capacitors, have sometimes been connected across the isolated vacuum chamber flanges in circular accelerators. The reason why these circuits are installed, the design criteria, and related technology adopted in the last fifteen years at the CERN PS (proton synchrotron) machine are described. Running the PS machine with increasing intensities (an increase of a factor 20 in the last 20 years), it was necessary to improve the early version of the RF-bypass. The latest version gave complete satisfaction except for some problems concerning the quality of the contacts