Zou G Q, Lei G J, Cao J Y, Duan X R
Southwestern Institute of Physics, Chengdu, 610041, China.
Rev Sci Instrum. 2012 Jul;83(7):073307. doi: 10.1063/1.4737184.
The ion beam optics for the neutral beam injection system on HL-2A Tokomak is studied by two- dimensional numerical simulation program firstly, where the emitting surface is taken at 100 Debye lengths from the plasma electrode. The mathematical formulation, computation techniques are described. Typical ion orbits, equipotential contours, and emittance diagram are shown. For a fixed geometry electrode, the effect of plasma density, plasma potential and plasma electron temperature on ion beam optics is examined, and the calculation reliability is confirmed by experimental results. In order to improve ion beam optics, the application of a small pre-acceleration voltage (∼100 V) between the plasma electrode and the arc discharge anode is reasonable, and a lower plasma electron temperature is desired. The results allow optimization of the ion beam optics in the neutral beam injection system on HL-2A Tokomak and provide guidelines for designing future neutral beam injection system on HL-2M Tokomak.
首先利用二维数值模拟程序对HL-2A托卡马克中性束注入系统的离子束光学进行了研究，其中发射面取在距等离子体电极100德拜长度处。描述了数学公式和计算技术。给出了典型的离子轨道、等势线和发射度图。对于固定几何形状的电极，研究了等离子体密度、等离子体电位和等离子体电子温度对离子束光学的影响，并通过实验结果证实了计算的可靠性。为了改善离子束光学，在等离子体电极和电弧放电阳极之间施加一个小的预加速电压（约100 V）是合理的，并且期望有较低的等离子体电子温度。这些结果有助于优化HL-2A托卡马克中性束注入系统中的离子束光学，并为设计未来HL-2M托卡马克中性束注入系统提供指导。
