HT-7托卡马克中破裂等离子体放电对器壁放气的影响  

Influence of Disruptive Plasma Discharge on Out-Gassing of Chamber Walls in HT-7 Tokamak

作　　者：唐明[1] 胡建生[1] 左桂忠[1] 真空科学及壁处理组 

机构地区：[1]中国科学院等离子体物理研究所,合肥230031

出　　处：《真空科学与技术学报》2011年第1期37-43,共7页Chinese Journal of Vacuum Science and Technology

基　　金：国家自然科学基金资助项目(11075185);国家磁约束核聚变能研究专项资助项目(2010GB104002)

摘　　要：未来托卡马克聚变反应堆中,等离子体破裂放电会使器壁释放大量的吸附气体,对燃料恢复、抽气系统设计、等离子密度控制等存在重要影响,在HT-7装置上破裂等离子体放电占总放电次数的10%左右,因此研究破裂放电对器壁出气的影响具有非常重要的意义。HT-7上初步的研究结果表明破裂放电时各气体成分分压峰值均高于正常放电,破裂后等离子密度出现上涨,在高密度破裂放电后密度涨幅主要在10%到70%之间,而在低密度情况下涨幅可以达到500%。并且破裂放电后,器壁气体的分压下降速率明显加快,表明破裂放电对器壁有很好的清洗效果,反过来干净的器壁对所释放出来的气体有很强的吸附能力。破裂放电对器壁出气的影响还同器壁的状态有关,硼化后破裂放电H的释放增加,而D的释放降低。在HT-7装置中,破裂放电后壁平均释放的粒子数约为5×1019个。高充气量下正常放电时壁的燃料滞留有饱和趋势,而破裂放电时未出现饱和趋势。Here,we addressed the impact of disruptive plasma discharge,10% of the total discharge,on the gas desorption from the inner walls of the vacuum chamber in the HT-7 superconductive Tokamak.The disruptive plasma discharge induced outgassing was evaluated statistically with mass spectroscopy and rapid acquisition of diagnosis signal in 2009 summer.The preliminary results show that the partial pressure peaks of all kinds of desorbed gases outweighed those in a normal discharge,and that the plasma density rose up,with an increase of 10% to 70% for high density plasma,whereas 500% for low density plasma.Besides,the disruption significantly cleaned the chamber walls,which strongly re-adsorbed gases nearby.The gas adsorption states on the wall strongly affect the outgassing.For instance,boronization increases H desorption,but decreases D desorption.The average number of desorbed molecules was estimated to be 5×1019.In the case of high fuel gas injection,no saturation of fuel retention on chamber walls,as frequently happens in a normal discharge,can be observed in the disruptive plasma discharge.

关 键 词：器壁出气 破裂 等离子体 HT-7托卡马克 

分 类 号：TB742[一般工业技术—材料科学与工程]