The vacuum system of the J-TEXT tokamak

A new vacuum system is designed and developed on the Joint Texas Experimental tokamak (J-TEXT), which consists of two pumping stations, a Taylor discharge cleaning (TDC) system and gas puffing. With this system, the vacuum vessel of the J-TEXT tokamak can easily reach the vacuum conditions which allow the operation of the machine. The sub-control system of the vacuum pumping systems with the self-protection function is reliable and easy to use. Inside the chamber, the base pressure can be lowered to 6.4x10-6Pa, and the total leakage and outgassing rates in 12h is below 1.5x10-8Pam3/s. Moreover, the TDC sub-system is used to clean the first facing walls of vacuum chamber to guarantee good wall conditions of the device before each run of the experimental campaign on the J-TEXT tokamak. The basic functions of the vacuum system meet the essential requirements for the present experiments on the J-TEXT tokamak.