Analytical model and simulation of the Schottky effect on a cryo-cooled bialkali photocathode

  • Hua-Mu Xie
  • Er-Dong Wang
  • Ke-Xin Liu


A bialkali photocathode with the quantum efficiency (QE) in the range of a few percent was fabricated for the 704 MHz SRF gun at Brookhaven National Laboratory. The photoemission properties of the bialkali photocathode in the superconducting radio frequency (SRF) gun were measured for the first time, and a good beam experiment result was obtained. The performance of the bialkali photocathode was investigated during the commissioning process of the 704 MHz SRF gun. The effect of electric field on the QE of the cryo-cooled cathode was characterized by an analytical model and a code for the first time.


Schottky effect Bialkali photocathode Surface potential Superconducting radio frequency gun 


  1. 1.
    R. Xiang, A. Arnold, P. Michel, et al., Thermal emittance measurement of the Cs2Te photocathode in FZD superconducting RF gun, in Proceedings of FEL2010, Malmö, Sweden (2010)Google Scholar
  2. 2.
    A. Jankowiak, Status of the Berlin Energy Recovery Linac Project bERLinPro, ERL 2017 (2017)Google Scholar
  3. 3.
    T. Xin, J.C. Brutus, S.A. Belomestnykh et al., Design of a high-bunch-charge 112-MHz superconducting RF photoemission electron source. Rev. Sci. Instrum. 87, 093303 (2016). CrossRefGoogle Scholar
  4. 4.
    W. Xu, Z. Altinbas, S.A. Belomestnykh et al., SRF Gun at BNL: First Beam and Other Commissioning Results, SRF 2015 (2015)Google Scholar
  5. 5.
    E. Wang, T. Rao, I. Ben-zvi, Enhancement of photoemission from and postprocessing of K2CsSb photocathode using excimer laser. Phys. Rev. Accel. Beams 17, 023402 (2014). CrossRefGoogle Scholar
  6. 6.
    H. Xie, T. Rao, I. Ben-Zvi, E. Wang, Experimental measurements and theoretical model of the cryogenic performance of bialkali photocathode and characterization with Monte Carlo simulation. Phys. Rev. Accel. Beams 19, 103401 (2016). CrossRefGoogle Scholar
  7. 7.
    I. Bazarov, B.M. Dunham, C.K. Sinclair, Maximum achievable beam brightness from photoinjectors. Phys. Rev. Lett. (2009). Google Scholar
  8. 8.
    H. Xie, Ph.D. Thesis, Fabrication and Physics of the High QE bi-alkali photocathode, Peking University (2016) (in Chinese)Google Scholar
  9. 9.
    W.E. Spicer, Modern Theory and Applications of Photocathodes, SLAC-PUB-6306 (1993)Google Scholar
  10. 10.
    A.R.H.F. Ettema, R.A. de Groot, Electronic structure of Cs2KSb and K2CsSb. Phys. Rev. B 66, 115102 (2002). CrossRefGoogle Scholar
  11. 11.
    J.L. Shay, Temperature dependence of the energy gap in GaAs. Phys. Rev. B 4, 1385 (1971). CrossRefGoogle Scholar
  12. 12.
    C. Jacoboni, L. Reggiani, The Monte Carlo method for the solution of charge transport in semiconductors with applications to covalent materials. Rev. Mod. Phys. 55, 645 (1983). CrossRefGoogle Scholar
  13. 13.
    L. Kalarasse, B. Bennecer, F. Kalarasse, Pressure effect on the electronic and optical properties of the alkali antimonide semiconductors Cs3Sb, KCs2Sb, CsK2Sb and K3Sb Ab initio study. J. Phys. Chem. Solids 71, 314 (2010). CrossRefGoogle Scholar

Copyright information

© Shanghai Institute of Applied Physics, Chinese Academy of Sciences, Chinese Nuclear Society, Science Press China and Springer Nature Singapore Pte Ltd. 2018

Authors and Affiliations

  1. 1.State Key Laboratory of Nuclear Physics and Technology, Institute of Heavy Ion PhysicsPeking UniversityBeijingChina
  2. 2.Brookhaven National LaboratoryUptonUSA

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