为进一步满足实验先进超导托卡马克装置（experimental advanced superconducting Tokamak, EAST）对等离子体加热的需求，中性束注入（neutral beam injection, NBI）系统需要更高的束功率。为此，EAST NBI研究室开展了120 keV束能量的加速器研制工作。整个加速器的分析研究需要从束流光学、绝缘支撑、主动冷却和材料等多个角度进行。从等离子体参数、静电透镜、电极间耐压以及装配误差等方面考虑，利用数值模拟程序对120 keV缝型四电极加速器中的束流轨迹、电场强度分布和束散角等束流光学相关参数进行了研究和优化，初步确定了新加速器的电极参数。该加速器在1.52 μp的导流系数下，垂直方向的最小束散角为0.6°，满足离子源氘离子束流强度为60 A和发散角小于1°的设计要求。

To further meet the plasma heating requirements of EAST (experimental advanced superconducting tokamak) device, NBI (neutral beam injection) system requires higher beam power. Accordingly, the EAST NBI laboratory has developed a 120 keV accelerator for this purpose. The analysis of the whole accelerator needs to be carried out from various perspectives such as beam optics, insulation support, active cooling and materials. Taking into account factors such as plasma parameters, electrostatic lens, voltage resistance between grids, and assembly errors, the numerical simulation program was utilized to beam optics analysis for the slit tetrode ion source accelerator. Beam trajectory, electric field strength distribution, and beam divergence angle were investigated and optimized to preliminarily determine the grid parameters of the new multi-slit accelerator. The accelerator obtains the beam with the minimum divergence angle of 0.6° in the vertical direction with perveance of 1.52 μp, meeting the design criteria for beam current intensity of 60 A and divergence angle below 1° of the ion source.