Abstract: We report the study of Na₂KSb photocathode as high brillance electronic injector. We have measured the properties of the multiphoton photoelectron emission with ultra short pulse laser (the wavelength is 1.06 μm, the width of a pulse is 50 ps). It was two photons effect. We have also tudied photoelectron emission limit.

Key words: Na₂KSb photocathode, ultra short laser pulse, photoelectron emission of subthreshold, space charge limit

摘要： 报告了作为高亮度电子注入器的钠钾锑光电阴极在YAG激光(λ=1.06μm，脉冲宽度为50ps)作用下的亚阈值光电发射，其为2光子发射。研究了阴极的光电发射限制问题，从实验上证明在激光能量比较大极间电压比较低时，阴极受空间电荷限制。

关键词: 钠钾锑阴极, 超短激光脉冲, 亚阈值光电发射, 空间电荷限制