聚变堆中性束注入系统的电偏转器概念设计

The conceptual design of NNBI electrostatic residual ion dump for fusion reactor

中性束注入是磁约束核聚变研究重要的辅助加热和电流驱动手段。由于负离子源中性束注入系统束能量高、束斑大,电偏转已经成为剩余离子剥离的首选方案,其剩余离子剥离设备被称为电偏转器。电偏转器作为实现束流中性化的核心设备,其性能决定了中性束注入系统的工作效率。本文提出了聚变堆主机关键系统研究中负离子源中性束注入系统电偏转器的概念设计方案,通过理论计算和束流沉积模拟初步确定了电偏转器的结构和其表面较为均匀的热负荷分布,完成了电偏转器的参数设计,此设计可为电偏转器进一步的工程设计提供设计参考。

[Background]Negative ion source based on neutral beam injector is an important auxiliary heating and current driving system for the China Fusion Experimental Test Reactor(CFETR).Due to the high beam energy and large beam spot of negative ion based neutral beam injection system(NNBI),electrical deflection of residual ions has become the preferred scheme for residual ion dumping.[Purpose]This study aims at the conceptual design of NNBI electrostatic residual ion dump system to deflect residual ions for neutralization of the beam.[Methods]According to the development objectives of NNBI,three polar plates and two channels were adopted for the conceptual design of electrostatic residual ion dump(ERID).A negative voltage was applied to the intermediate plate to form a deflection electric field between the channels.When the mixed beam passed through the deflection channel,the residual ions were deflected to the panel due to the action of electric field force.Through theoretical calculation and beam deposition simulation,the structure of the ERID and more uniform heat load distribution on its surface were preliminarily determined.[Results&Conclusions]The simulation results show that the ERID can deflect the residual ions under the parameter design,providing a reference for future engineering design.