强流氘束引出系统与加速管束流匹配的研究

为增加传输通过加速管的束流强度，提高中子发生器的中子产额，采用Particle-in-cell(PIC)程序模拟研究了入射束强度在10～150 mA范围内，不同初始参数条件下D⁺₁束在加速管中的传输状态。结果表明，当入射束在加速管入口处的归一化发射度取0.25 πcm•mrad，Courant-Snyder参数α=-4、β=60 cm/rad时，50～100 mA D⁺₁束与加速管匹配良好。根据匹配参数，对双等离子体离子源的引出系统进行了优化，结果显示，在引出系统与加速管之间放置两个螺线管透镜和1个光阑，能有效去除D⁺₂、D⁺₃离子，实现100 mA D⁺₁束顺利传输通过加速管的目的。

Study on Beam Matching of Extraction System and Accelerating Column for High Current Deuterium Beam

In order to increase the intensity of the deuterium beam passing through the accelerating column, and the neutron yield of the neutron generator as well, the Particle-in-cell simulation was used to study the beam transmission in the accelerating column, in which the initial parameters of the deuterium beam were different and the intensities of the deuterium beam were 10-150 mA. The results show that when the normalized emittance of the incident beam at the entrance of the accelerating column is 0.25 πcm•mrad and the Courant-Snyder parameter α=-4, β=60 cm/rad, the deuterium beam of 50-100 mA will match the accelerating column. According to the deuterium beam matching parameters, the extraction system of the duoplasmatron ion source was optimized. The results show that by means of placing two solenoid lenses and an aperture between the extraction system and the accelerating column, D⁺₁ beam of 100 mA can be transmitted smoothly through the accelerating column and the unwanted ions D⁺₂ and D⁺₃ can be eliminated effectively.