Introduction of Vacuum systems on EAST
Vacuum systems：Vacuum systems as the basic configuration of the magnetic confinement fusion device mainly includes pumping system, fueling system, wall conditioning, measurement and control, etc., which provide a good vacuum environment, clean wall condition, fuel injection and particle exhaust, and directly affect the quality of the high-temperature plasma.
Fig 1. View of vacuum systems and relative systems of EAST
Pumping system: displacement of EAST pumping pipes and backing pumps, improvement of pumping capacity, displacement and upgrades of pumping system of wave heating, reconstruction of vacuum water cooling/gas supply/venting system
Wall conditioning system: GDC and ICRF cleaning systems upgrades
Fueling system: displacement of gas puffing, SMBI and PI systems；add two divertor SMBI systems；add the new injection tubes of PI at the divertor zone
Vacuum control system: displacement of vacuum control system, performance improvement
Distribution of Vacuum systems：Move the pumping tubes from C port to G port，and move the relative backing pumping systems；
Fig 2. Main pumping tubes of EAST
Main parameters： The plasma discharge vacuum vessel: provide enough and controllable pumping speed to achieve an ultimate vacuum lower than 1x10-5Pa with impurity content <1% before plasma operation. Cryostat: achieve an ultimate vacuum lower than 1x10-4Pa after magnet cooling down.