Coaxial 30 kV Connectors for the RG220/U Cable 20 Years of Operational Experience

For the fast pulsed magnet system of CERN's SPS and LEP particle accelerators, a special type of moulded coaxial high voltage cable connector is used in large quantities. These connectors are mounted on coaxial transmission lines, which connect pulse generators in buildings at ground level to the fast pulsed magnets situated in an underground tunnel. Well over 1500 such connectors have already been installed and many more will be needed for the construction of the LHC. This 14 TeV Large Hadron Collider, which has a circumference of 27 km, is now under construction at CERN. The paper summarizes the operational experience over the last 20 years and the design principles of the connector. It explains how the excellent reliability and the extremely low failure rate were achieved and outlines the causes of the rare replacements. The paper also discusses the ageing effects caused by radiation, as well as wear and tear during installation and manipulation. Finally it gives a report on our experience with coaxial connectors for cables of 30 kV-18 *, 60 kV-15 *, 60 kV-50 *, and 70 kV-42 *.