1. Photocathode behavior during high current running in the Cornell energy recovery linac photoinjector
- Author
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Luca Cultrera, Jared Maxson, Ivan Bazarov, Sergey Belomestnykh, John Dobbins, Bruce Dunham, Siddharth Karkare, Roger Kaplan, Vaclav Kostroun, Yulin Li, Xianghong Liu, Florian Löhl, Karl Smolenski, Zhi Zhao, David Rice, Peter Quigley, Maury Tigner, Vadim Veshcherevich, Kenneth Finkelstein, Darren Dale, and Benjamin Pichler
- Subjects
Nuclear and particle physics. Atomic energy. Radioactivity ,QC770-798 - Abstract
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.
- Published
- 2011
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