Photocathode behavior during high current running in the Cornell energy recovery linac photoinjector
Photocathode behavior during high current running in the Cornell energy recovery linac photoinjector
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DOI：
10.1103/physrevstab.14.120101
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发表时间：
2011-12-08
影响因子：
--
通讯作者：
Pichler, Benjamin
中科院分区：
文献类型：
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作者：
Cultrera, Luca;Maxson, Jared;Pichler, Benjamin
康奈尔大学的能量回收直线加速器（ERL）光注入器最近展示了在20毫安下工作约8小时，利用沉积在硅衬底上的多碱光电阴极。我们描述了光电阴极沉积的配方，并将详细说明运行的参数。光电阴极的运行后分析表明，衬底存在明显的损伤，可能是由于残余束线气体的离子反轰击。虽然衬底损伤的确切原因尚不清楚，但我们描述了多种表面表征技术（x射线荧光光谱，x射线衍射，原子力和扫描电子显微镜），用于研究光电阴极表面在用于大电流光束生产后的有趣形态和晶体学特征。最后，我们提出了一个简单的离子反轰击晶体损伤模型，该模型定性地符合衬底表面损伤的分布。
The Cornell University energy recovery linac (ERL) photoinjector has recently demonstrated operation at 20 mA for approximately 8 hours, utilizing a multialkali photocathode deposited on a Si substrate. We describe the recipe for photocathode deposition, and will detail the parameters of the run. Post-run analysis of the photocathode indicates the presence of significant damage to the substrate, perhaps due to ion back-bombardment from the residual beam line gas. While the exact cause of the substrate damage remains unknown, we describe multiple surface characterization techniques (x-ray fluorescence spectroscopy, x-ray diffraction, atomic force, and scanning electron microscopy) used to study the interesting morphological and crystallographic features of the photocathode surface after its use for high current beam production. Finally, we present a simple model of crystal damage due to ion back-bombardment, which agrees qualitatively with the distribution of damage on the substrate surface.