Author: Goto, K.
Paper Title Page
THPOPT028 Dependence of CsK2Sb Photocathode Performance on the Quality of Graphene Substrate Film 2637
 
  • L. Guo, K. Goto, Y. Takashima
    Nagoya University, Nagoya, Japan
  • H. Yamaguchi
    LANL, Los Alamos, New Mexico, USA
  • M. Yamamoto
    KEK, Ibaraki, Japan
 
  Funding: U.S.-Japan Science and Technology Cooperation Program in High Energy Physics
A photocathode that extracts electrons by irradiating a semiconductor or metal with a laser is applied to advanced accelerators and electron microscopes as a high-performance cathode. In particular, the CsK2Sb photocathode is of interest because it has features such as low emittance, excitability with visible light, and high quantum efficiency. Generally, the CsK2Sb photocathode is produced by depositing a cathode element on a substrate, so that the cathode performance strongly depends on the surface condition of the substrate. We have found graphene as reusable substrate, which has the property of being chemically inactive. In this study, graphene film quality dependence of CsK2Sb photo-cathode performance was evaluated. Specifically, CsK2Sb cathode was deposited using different quality graphene film substrates and their QE values and uniformity were compared. The quality of graphene films was analyzed using X-ray Photoelectron Spectroscopy (XPS) and X-ray absorption spectroscopy (XAS). We found that the graphene film can be cleaned by heating at 500 deg. The QE of the cathode on a good quality graphene film was higher and more uniform than that on a poor quality graphene film.
 
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2022-THPOPT028  
About • Received ※ 16 May 2022 — Revised ※ 10 June 2022 — Accepted ※ 10 June 2022 — Issue date ※ 24 June 2022
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