用于DC–SC超导光电子枪中的光阴极的研制

DC-SC超导光阴极微波电子枪是一种新型的高平均流强电子源,本文介绍了其中的关键部件—光阴极的研制.在自行研制的光阴极制备室里成功制备了两种光阴极:Cs₂Te和Cs₃Sb光阴极.Cs₂Te光阴极的寿命长,用266nm紫外光激发,量子效率QE>25%,真空中(1×10^－5Pa)寿命50h.Cs₃Sb光阴极是多层膜结构,用532nm激光激发,量子效率2%,真空中(10^－5Pa)寿命只有几个小时.两者都可以满足电子枪的设计要求,但是由于Cs₂Te光阴极更稳定,在目前的DC-SC超导光电子枪调试实验中采用这种光阴极

Research and Fabrication of the Photocathodes for DC-SC Photoinjector

DC-SC photoinjector is a new injector based on the laser-driven photocathode. It is designed to produce the electron beam with high average current required by high average power FEL experiments. For this projector, Cs 2Te and Cs 3Sb photocathodes are fabricated in a self-designed preparation chamber, which is bakable and the vacuum can reach values of 10 -6 Pa. Cs 2Te is excited by 266nm UV laser, and its quantum efficiency(QE) is above 2 5% for more than 50 hours, and the QE of Cs 3Sb at 532nm is about 2% and stable for only several hours in vacuum. They can provide enough electrons for our electron gun. Because of its stability, Cs 2 Te is adopted in the test facility of the DC-SC photoinjector.