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

Main upgrades:

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.