激光驱动光电阴极的研究进展

随着高能粒子探测、超导腔加速器等领域的快速发展,对光电阴极的光电性能提出了更高的要求。光电阴极的材料决定了光电发射的量子效率、暗发射电流和出射电子能量分布等重要性能;激光在亮度、方向性、单色性、相干性等方面远高于普通光源,使得用激光驱动光电阴极具有更加优良的光电流和量子效率等光电性能。本文介绍了几种类型的光电阴极发射材料,包括Na₂KSb光电阴极、Cs₃Sb光电阴极、K₂CsSb光电阴极和Cu光电阴极。其中对Na₂KSb光电阴极的制备以及光电性能测试方法进行了详细介绍;对Cs₃Sb光电阴极的制备及影响其寿命的因素进行分析介绍,并且对Cs₃Sb光电阴极的改良进行了总结;对于K₂CsSb光电阴极分别通过实验和蒙特卡洛法测量其光电性能,分析总结了影响其量子效率和光电发射寿命的因素;对于Cu光电阴极,分析了包覆CuBr对铜光电阴极的量子效率的影响。

Latest Progress of Laser Driven Photocathode: A Review Study

The latest development of the laser-driven photocathode,an advanced laser technology,was tentatively reviewed.The photocathode driven by laser has been attracting extensive research efforts not only because of its many advantages over the conventional light source,including higher luminance/directivity/monochromatism/laser-coherence,and much stronger photocurrent and remarkable quantum efficiency,but also because of its wide applications in high-energy particle detection and superconducting cavity accelerator.The discussions with specific examples focused on:i)Advanced materials of Na₂KSb,Cs₃Sb,K₂CsSb and Cu photocathodes; ii)Synthesis,fabrication,characterization,and improvement methods of Na₂KS,Cs₃Sb and K₂CsSb photocathodes; and iii) The influence of material-synthesis and device fabrication conditions on quantum efficiency and photoelectric emission life of K₂CsSb and Cu photocathodes.Moreover,the development trends,basis and technological problems,possible solutions and potential applications of laser-driven photocathode were also briefly discussed in a thought provoking way.