【摘要】 碳纳米管(Carbon Nanotubes, CNTs)是一种重要的冷阴极电子发射材料，然而在场发射过程中由于碳纳米管表面起伏的影响使得电子发射方向具有一定发散，而发散角的大小影响电子在真空中的运动方向和电子束的聚焦尺寸。因此，通过粒子仿真与电子束的荧光成像实验相结合的方法，研究设计出一种具有凹槽结构的CNTs,探究了电子发散角在不同凹槽深度下的变化规律，有效地减小了电子束的发散角。特别是当阴极低于凹槽顶面时，电子发散角小于10°,具有良好的方向性，可应用于各类高性能电子枪。更多还原

【Abstract】 Carbon nanotubes(CNTs) represent a significant class of cold cathode electron emission materials. However, CNTs exhibit dispersed electron emission directions in field emission, and the emission angle influences the trajectory of electrons in vacuum and the focusing size of electron beams. To address this problem, this study employs a combination of particle simulations and fluorescence imaging experiments of electron beams to investigate and design a CNTs cathode with groove structure. The variation in electron emission angle with different groove heights is explored, so as to optimize the structure and reduce the divergence angle of the electron beam. Notably, when the cathode is positioned below the top surface of the groove, the electron emission angle is less than 10°, demonstrating excellent directionality. The research makes CNTs suitable for various high-performance electron guns.更多还原