Physical Review Accelerators and Beams
CsxKySb photocathodes grown on GaAs and molybdenum substrates were evaluated using a –300 kV dc high voltage photogun and diagnostic beam line. Photocathodes grown on GaAs substrates, with varying antimony layer thickness (estimated range from < 20 nm to > 1 um), yielded similar thermal emittance per rms laser spot size values (~0.4 mm mrad / mm) but very different operating lifetime. Similar thermal emittance was obtained for a photocathode grown on a molybdenum substrate but with markedly improved lifetime. For this photocathode, no decay in quantum efficiency was measured at 4.5 mA average current and with peak current 0.55 A at the photocathode.
Original Publication Citation
Wang, Y., Mamun, M. A., Adderley, P... Wijethunga, S., Yoskowitz, J., Zhang, S., et al. (2020). Thermal emittance and lifetime of alkali-antimonide photocathodes grown on GaAs and molybdenum substrates evaluated in a -300 kV dc photogun. Physical Review Accelerators and Beams, 23(10), 11 pp., Article 103401. https://doi.org/10.1103/PhysRevAccelBeams.23.103401
Wang, Y.; Mamun, M. A.; Adderley, P.; Bullard, B.; Grames, J.; Hansknecht, J.; Hernandez-Garcia, C.; Krafft, G. A.; Palacios-Serrano, G.; Poelker, M.; Stutzman, M. L.; Suleiman, R.; Tiefenback, M.; Wijethunga, S.; Yoskowitz, J.; and Zhang, S., "Thermal Emittance and Lifetime of Alkali-Antimonide Photocathodes Grown On GaAs and Molybdenum Substrates Evaluated in a -300 kV dc Photogun" (2020). Physics Faculty Publications. 445.