Bi-alkali antimonide photocathode growth: An X-ray diffraction study

Journal Article · Thu Jul 21 00:00:00 EDT 2016 · Journal of Applied Physics

DOI:https://doi.org/10.1063/1.4959218· OSTI ID:22597769

Schubert, Susanne ^[1]; Wong, Jared; Feng, Jun; Karkare, Siddharth; Padmore, Howard ^[1]; Ruiz-Osés, Miguel; Smedley, John; Muller, Erik; Ding, Zihao; Gaowei, Mengjia; Attenkofer, Klaus; Liang, Xue ^[2]; Xie, Junqi ^[3]; Kühn, Julius ^[4]

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1. Lawrence Berkeley National Laboratory, 1 Cyclotron Road, Berkeley, California 94720 (United States)
2. Brookhaven National Laboratory, Upton, New York 11973 (United States)
3. Argonne National Laboratory, 9700 South Cass Avenue B109, Lemont, Illinois 60439 (United States)
4. Helmholtz-Zentrum Berlin, Albert-Einstein Strasse 15, Berlin 12489 (Germany)

Bi-alkali antimonide photocathodes are one of the best known sources of electrons for high current and/or high bunch charge applications like Energy Recovery Linacs or Free Electron Lasers. Despite their high quantum efficiency in visible light and low intrinsic emittance, the surface roughness of these photocathodes prohibits their use as low emittance cathodes in high accelerating gradient superconducting and normal conducting radio frequency photoguns and limits the minimum possible intrinsic emittance near the threshold. Also, the growth process for these materials is largely based on recipes obtained by trial and error and is very unreliable. In this paper, using X-ray diffraction, we investigate the different structural and chemical changes that take place during the growth process of the bi-alkali antimonide material K{sub 2}CsSb. Our measurements give us a deeper understanding of the growth process of alkali-antimonide photocathodes allowing us to optimize it with the goal of minimizing the surface roughness to preserve the intrinsic emittance at high electric fields and increasing its reproducibility.

• OSTI ID: 22597769
• Journal Information: Journal of Applied Physics, Vol. 120, Issue 3; Other Information: (c) 2016 Author(s); Country of input: International Atomic Energy Agency (IAEA); ISSN 0021-8979
• Country of Publication: United States
• Language: English

Related Subjects

71 CLASSICAL AND QUANTUM MECHANICS
GENERAL PHYSICS
75 CONDENSED MATTER PHYSICS
SUPERCONDUCTIVITY AND SUPERFLUIDITY
ANTIMONIDES
ELECTRIC FIELDS
ELECTRONS
ENERGY RECOVERY
ERRORS
FREE ELECTRON LASERS
LINEAR ACCELERATORS
PHOTOCATHODES
QUANTUM EFFICIENCY
RADIOWAVE RADIATION
ROUGHNESS
SURFACES
VISIBLE RADIATION
X-RAY DIFFRACTION