HL-2A装置硅化镀膜壁处理控制杂质行为研究

Study of Impurity Control by Siliconization on HL-2A Tokamak

硅化壁处理能有效控制等离子体杂质和再循环水平,是HL-2A装置的常规壁处理手段。介绍了HL-2A装置的硅化壁处理系统以及硅化镀膜壁处理控制杂质行为的主要研究进展。HL-2A装置硅化壁处理系统包括离线硅化和在线硅化壁处理系统,分别采用辉光放电辅助沉积以及等离子体放电辅助沉积进行硅化镀膜壁处理。实验结果表明,离线硅化壁处理后氧杂质明显降低,但随着实验进行会逐渐增加,硅化镀膜寿命约150炮。为进一步开展研究,HL-2A采用了在线硅化壁处理技术,研究发现在线硅化壁处理过程中碳、氧、铁等杂质均有所减少。两种硅化方式下真空室内的H_(2)O、CO含量均明显降低,在线硅化壁处理耗气量远少于离线硅化。通过硅化壁处理,有效地提升了HL-2A等离子体性能,也为未来聚变装置稳态运行器壁的处理提供了重要技术参考。

The plasma impurity and recycling could be effectively controlled by siliconization,which is a conventional wall conditioning method for HL-2A Tokamak.The recent progress of the siliconization system and the impurity control behavior by siliconizaition on HL-2A are introduced.The siliconization system includes two subsytems:one is used for the offline siliconization experiment which employs glow discharge for coating,and the other one is used for the real-time siliconization experiment which implements coating during plasma discharge.The experimental results show that the oxygen impurity is significantly reduced after offline siliconization,but it will gradually increase following the plasma discharge experiment.The offline siliconization effect lasted for about 150 shots.In order to make further study,real-time siliconization was developed on HL-2A.The results show that carbon,oxygen and iron levels all drop during the real-time siliconization.The amounts of H_(2)O and CO in the vacuum vessel were decreased after both the offline and real-time siliconization,while the realtime siliconization consumed less gas.The plasma performance of HL-2A was effectively improved by siliconization.The study provides an important technical support for the wall conditioning of the future steady-state operation fusion device.