Mistry, S.; Kamps, T.; Kühn, J.; Wang, C.: Multi-Alkali Antimonide Photocathode Development for High Brightness Beams. In: Frank Zimmermann ... [Ed.] : IPAC2022 : Proceedings of the 13th International Particle Accelerator Conference, in Bangkok, Thailand, 12–17 June 2022Geneva, Switzerland: JACoW Publishing, 2022. - ISBN 978-3-95450-227-1, p. THPOPT019/1-4
https://jacow.org/ipac2022/papers/thpopt019.pdf
Open Access Version
Abstract:
Photocathode R&D at the Helmholtz-Zentrum Berlin (HZB) is driven by the motivation to produce high brightness electron beams for the SRF photoinjector test facility, Sealab/ bERLinPro. Multi-alkali antimonides are the choice photocathode material due to high quantum efficiency (QE) and low intrinsic emittance in the visible range. In this work a more robust alternative to the tried and tested Cs-K-Sb is considered. Na-K-Sb offers similar advantages to Cs-K-Sb including, high QE at green wavelengths but moreover, it offers excellent stability at elevated temperatures. This property could lengthen the cathode lifetime by enhancing the robustness of the photocathode inside the SRF gun. In this work, a status report showcasing first results towards the development of a growth procedure for Na-K-Sb is presented by means of spectral response and XPS measurements conducted in the HZB photocathode lab.