Dresden 2017 – scientific programme
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AKBP: Arbeitskreis Beschleunigerphysik
AKBP 6: Poster Session
AKBP 6.4: Poster
Wednesday, March 22, 2017, 18:30–20:00, P4
Magnesium photocathodes in superconducting RF photoelectron injectors — •Jochen Teichert1, André Arnold1, Pengnan Lu1,2, Petr Murcek1, Hannes Vennekate1,2, and Rong Xiang1 — 1HZDR, Dresden, Germany — 2TU Dresden, Dresden, Germany
To improve the quality of photocathodes is one of the critical issues in enhancing the stability and reliability of the photoinjector systems. Using metallic photocathodes for the ELBE superconducting RF photoelectron source (SRF Gun) is the primary choice to prevent contamination to the superconducting cavity.
Magnesium has a low work function (3.6 eV) and is relatively chemically stable. The SRF Gun has successfully provided electron beams to ELBE users with Mg photocathodes. However, the present cleaning process with a high intensity laser (activation) is time consuming and produces an unwanted surface roughness.
Alternative surface cleaning methods, ion beam sputtering and thermal treatment will be investigated and the results will be compared with the laser cleaning. For this reason the existing vacuum setup has to be modified, the new cleaning procedures have to be tested and optimized, and the quantum efficiency of the photo cathode samples has to be measured. Furthermore Mg samples of different microstructure, composition, and from different suppliers will be treated and measured.