摘要
The proton beam line vacuum system of HIRFL is about ten-metre long. It is made up from vacuum chambers and pumps and some equipment for vacuum measuring and beam detecting. This system's surface area is 8 ×104 cm2 and the bulk is 110 1. It is required that this system's vacuum degree must be lower than 1×10-6 Pa. To get this target, we cleaned the vacuum chambers in our Ultrasonic Cleaning Station and then