摘要: 高功率、大电流密度、细聚焦X射线源在工业无损探伤、医学成像、安全技术等领域具有广泛的应用。本文设计了一种用于X射线管的静电自会聚电子枪，该电子枪包括三部分：LaB6 热阴极发射体、带有矩形孔和斜槽的聚焦极、阳极。采用EBS 粒子束模拟软件对该电子枪的结构进行了模拟仿真。仿真结果表明：电子枪的聚焦能力主要取决于聚焦极倾角，当聚焦极倾角为46°时，达到理想的电子束聚焦效果；随着阴栅距的增加，阳极电流以及束斑电流分布均匀性显著降低，当阴栅距为0.3 mm，可在工艺条件允许下，得到具有较大阳极电流以及理想电流分布的电子束。

High power, high current density, ne focus X-ray sources are widely used in the eld of industrial nondestructive testing, medical imaging, security technology, and so on. An electrostatic self-focusing lanthanum hexaboride electron gun applied in X-ray source is designed using electron beam simulation (EBS) software. The electron gun consists of three parts: a lanthanum hexaboride thermionic emitter, a focusing electrode with a trapezoidal focusing groove and a rectangular hole, and an anode. The simulated results show that the inclination angle of focusing electrode has strong in uence on electron focusing property and the best inclination angle is 46°. The anode current and the uniformity of the distribution are decreased with increasing the distance between the gate and cathode, and the best distance between the gate and cathode value is 0.3 mm.