面向EAST装置长脉冲高参数等离子体运行的真空系统性能提升

Upgraded Vacuum System for Long Pulse High Parameter Plasma Discharge in EAST

托卡马克核聚变装置真空系统为等离子体放电真空腔室提供良好的真空环境、洁净器壁、实时燃料注入及粒子排出等条件,直接影响高温等离子体的品质。真空系统作为EAST装置的重要组成部分,包括真空抽气系统、等离子体加料系统、壁处理系统以及测量与控制系统。针对EAST装置长脉冲高参数等离子放电的需求,对真空系统进行了一系列的升级改造,包括增加外置低温泵数量、研发大抽速及大容量低温泵、提高加料系统可靠性、增加偏滤器超声分子束注入系统、提高离子回旋射频放电功率>50 kW等。通过这些改造,增加了泵的抽气能力及加料系统的加料能力,提高了器壁的清洗效果,使等离子体放电真空室压力达到约1.5×10^(-6) Pa。真空系统的成功升级,促进了EAST装置,如>400 s高约束模(H模)、1056s长脉冲等离子体等多项创世界纪录成果的获得,为未来ITER及聚变堆真空系统的设计与运行提供了重要的参考。

The vacuum system of Tokamak provides adequate vacuum,clean wall condition,real-time fuel injection and particle exhaust,which directly influences the high temperature performance.The vacuum system,as an important integral part of EAST,includes vacuum pumping system,plasma fueling system,wall conditioning system,vacuum measurement and control system.To realize the targets of long pulse and high parameter plasma discharges for EAST,some upgrades of the vacuum system have been conducted,including increased the number of pumps,increased the pumping speed and capacity of cryopumps,improved the reliability of SMBI and increased new divertor SMBI system to reduce gas injection delay time,increased ICRF cleaning power to>50 kW.Through these upgrades,it increases the pumping capability,improves the effect of wall conditioning,and results in a recorded pressure of 1.5×10^(-6) Pa in vacuum vessel.Based on these upgrades,some record plasmas,such as>400 s high confinement mode(H-mode)and 1056s long pulse plasma are successfully achieved in EAST,which provides a very important reference for vacuum system design and operation for ITER and future fusion reactor devices.