Document Type

Article

Publication Date

2024

DOI

10.1103/PhysRevAccelBeams.27.123401

Publication Title

Physical Review Accelerators and Beams

Volume

27

Pages

123401 (1-14)

Abstract

GaAs photocathodes in dc high-voltage photoguns are highly susceptible to ion back-bombardment, which reduces the photocathode quantum efficiency and limits the useful operating lifetime for producing polarized electron beams. This paper demonstrates that applying a small positive bias to the photogun anode can significantly suppress ion back-bombardment and increase charge lifetime. This technique was studied extensively using the Continuous Electron Beam Accelerator Facility photogun, where highly polarized electron beams created using a strained-superlattice GaAs/GaAsP photocathode were used and charge lifetimes improved by almost a factor of 2. A new simulation code ionator was developed to model ion production and tracking in order to better understand and explain the factors that led to the performance improvement. Results of the experiments and simulations are discussed in detail.

Rights

© 2024 The Authors.

Published under the terms of the Creative Commons Attribution 4.0 International (CC BY 4.0) License.

Original Publication Citation

Yoskowitz, J. T., Krafft, G. A., Palacios-Serrano, G., Wijethunga, S. A. K., Grames, J., Hansknecht, J., Hernandez-Garcia, C., Poelker, M., Stutzman, M. L., Suleiman, R., Valerio-Lizarraga, C. A., & Van Der Geer, S. B. (2024). Charge lifetime improvement of the Continuous Electron Beam Accelerator Facility photogun with a biased anode. Physical Review Accelerators and Beams, 27, 1-14, Article 123401. https://doi.org/10.1103/PhysRevAccelBeams.27.123401

ORCID

0000-0003-1792-6603 (Yoskowitz), 0000-0002-0328-5828 (Krafft), 0000-0002-5331-6127 (Serrano), 0000-0002-8765-9208 (Wijethunga)

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