Cs${}_x$K${}_y$Sb photocathodes grown on GaAs and molybdenum substrates were evaluated using a -300 kV dc high voltage photogun and diagnostic beamline. Photocathodes grown on GaAs substrates with varying antimony layer thickness (estimated range from 1 um) yielded similar thermal emittance per rms laser spot size values (~ 0.4 mm mrad/mm) but very different operating lifetime. Similar thermal emittance was obtained for a photocathode grown on a molybdenum substrate but with markedly improved lifetime. For this photocathode, no decay in quantum efficiency was measured at 4.5 mA average current and with peak current 0.55 A at the photocathode.

中文翻译：

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在-300 kV直流光枪中评估了在GaAs和钼衬底上生长的碱-锑化物光阴极的热发射率和寿命

Cs${}_X$ķ${}_{ÿ}$使用-300 kV直流高压光枪和诊断束线评估了在GaAs和钼衬底上生长的Sb阴极。在具有不同锑层厚度（估计范围为1 um）的GaAs衬底上生长的光电阴极，每rms激光点尺寸值（约0.4 mm mrad / mm）产生相似的热发射率，但工作寿命却大不相同。对于在钼衬底上生长的光电阴极，获得了相似的热发射率，但寿命得到了显着改善。对于该光电阴极，在4.5 mA平均电流和在光电阴极的峰值电流为0.55 A时，未测量到量子效率的衰减。