Characterization of photocathode damage during high current operation of the cornellerl photoinjector

Jared Maxson, Luca Cultrera, Ivan Bazarov, Bruce Dunham, Sergey Belomestnykh, John Dobbins, Siddharth Karkare, Roger Kaplan, Vaclav Kostroun, Yulin Li, Xianghong Liu, Florian L̈ohl, Karl Smolenski, Zhi Zhao, David Rice, Peter Quigley, Maury Tigner, Vadim Veshcherevich, Kenneth Finkelstein, Darren DaleBenjamin Pichler

Research output: Chapter in Book/Report/Conference proceedingConference contribution

Abstract

The Cornell ERL Photoinjector prototype has recently demonstrated successful operationat 20 mA for 8 hours using a bi-alkali photocathode grown on a Si substrate. Thephotocathode film was grown off center, and remained relatively undamaged; however, uponremoval from the gun, the substrate at the gun electrostatic center displayed significantvisible damage. Here we will describe not only the parameters of that particular highcurrent run, but a suite of post-operation surface morphology and crystallographicmeasurements, including X-ray fluorescence, Xray diffraction, and contact profilometry, performed about the damage site and photocathode film. The data indicate violenttopological changes to the substrate surface, as well as significant inducedcrystallographic strain. Ion back-bombardment is proposed as a possible mechanism fordamage, and a simple model for induced crystal strain is proposed (as opposed to ioninduced sputtering), and is shown to have good qualitative agreement with the spatialdistribution of damage.

Original languageEnglish (US)
Title of host publicationIPAC 2012 - International Particle Accelerator Conference 2012
Pages2717-2719
Number of pages3
StatePublished - Dec 1 2012
Externally publishedYes
Event3rd International Particle Accelerator Conference 2012, IPAC 2012 - New Orleans, LA, United States
Duration: May 20 2012May 25 2012

Publication series

NameIPAC 2012 - International Particle Accelerator Conference 2012

Conference

Conference3rd International Particle Accelerator Conference 2012, IPAC 2012
CountryUnited States
CityNew Orleans, LA
Period5/20/125/25/12

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ASJC Scopus subject areas

  • Nuclear and High Energy Physics

Cite this

Maxson, J., Cultrera, L., Bazarov, I., Dunham, B., Belomestnykh, S., Dobbins, J., Karkare, S., Kaplan, R., Kostroun, V., Li, Y., Liu, X., L̈ohl, F., Smolenski, K., Zhao, Z., Rice, D., Quigley, P., Tigner, M., Veshcherevich, V., Finkelstein, K., ... Pichler, B. (2012). Characterization of photocathode damage during high current operation of the cornellerl photoinjector. In IPAC 2012 - International Particle Accelerator Conference 2012 (pp. 2717-2719). (IPAC 2012 - International Particle Accelerator Conference 2012).