Experience in the Manufacture of Vacuum Feedthroughs with Cooling Water Jacket for the Transverse Feedback Kicker of BEPCⅡ

A non-standard water-cooled,ultra-high vacuum(UHV) feedthrough has been successfully developed for the transverse feedback kicker of the Second Upgrade Project of Beijing Electron and Positron Collider.The self-developed feedthrough with water-cooling jacket was made of composite materials,including ceramics,oxygen-free copper,stainless-steel and kovar-alloy.The discussions with specific examples focused on: i) The strengths and weaknesses of the four upgraded design versions;ii) The technical problems and solutions,including but not limited to the vacuum-leakage of ceramics,leakage discharge,elastic leakage,fluid percolation at molecular scale,welding of metal-ceramic joints,and shock resistance.The test results show that the prototyped water-cooled ceramic UHV feedthrough meets the stringent design requirements and works pretty well.We suggest that the self-developed feedthrough be some technological in development of non-standard vacuum spare-parts and vacuum components.