Simulation of Electrostatic Self-Focusing Lanthanum Hexaboride Electron Gun Applied in X-Ray Source#br#

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.