${\mathrm{Cs}}_x{\mathrm{K}}_y\mathrm{Sb}$ photocathodes grown on GaAs and molybdenum substrates were evaluated using a $-300\mathrm{kV}$ dc high voltage photogun and diagnostic beam line. Photocathodes grown on GaAs substrates, with varying antimony layer thickness (estimated range from $<20\mathrm{nm}$ to $>1\mathrm{um}$), yielded similar thermal emittance per rms laser spot size values ($\sim 0.4\mathrm{mm}\mathrm{mrad}/\mathrm{mm}$) 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a-300kVdc光电枪中评估了在GaAs和钼衬底上生长的碱金属锑化物光电阴极的热发射率和寿命

${\mathrm{Cs}}_X{\mathrm{ķ}}_{ÿ}锑$ 在GaAs和钼衬底上生长的光电阴极的发光性能进行了评价。 $-300\mathrm{千伏}$直流高压光枪和诊断光束线。在GaAs衬底上生长的光电阴极，其锑层厚度各不相同（估计范围为$<20\mathrm{纳米}$ 至 $>\mathrm{1个}嗯$），每rms激光光斑尺寸值产生的热辐射相似（$〜0.4\mathrm{毫米}\mathrm{姆拉德}/\mathrm{毫米}$），但使用寿命不同。对于在钼衬底上生长的光电阴极，获得了相似的热发射率，但寿命得到了显着提高。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。