Pinayev, I. Fu, W. Hao, Y. Harvey, M. Hayes, T. Jamilkowski, J.P. Jing, Y.C. Kankiya, P. K. Kayran, D. Kellermann, R. Litvinenko, V. Mahler, G.J. Mapes, M. Mernick, K. Mihara, K. Miller, T.A. Narayan, G. Paniccia, M.C. Pekrul, W.E. Petrushina, I. Rao, T. Severino, F. Sheehy, B. Skaritka, J. Smith, K.S. Tuozzolo, J.E. Wang, E. Wang, G. Xu, W. Zaltsman, A. Zhao, Z. JACoW Geneva, Switzerland 978-3-95450-180-9 10.18429/JACoW-NAPAC2016-WEPOB59 English 1024-1026 WEPOB59 ion cathode gun laser cavity Contribution to a conference proceedings 2017 2017-01 http://dx.doi.org/10.18429/JACoW-NAPAC2016-WEPOB59 https://jacow.org/napac2016/papers/wepob59.pdf The Coherent Electron Cooling Proof-of-Principle (CeC PoP) experiment employs a high-gradient CW photo-injector based on the superconducting RF cavity. Such guns operating at high accelerating gradients promise to revolutionize many sciences and applications. They can establish the basis for super-bright monochromatic X-ray and gamma ray sources, high luminosity hadron colliders, nuclear waste transmutation or a new generation of microchip production. In this paper we report on our operation of a superconducting RF electron gun with a high accelerating gradient at the CsK2Sb photo-cathode (i.e. ~ 20 MV/m) generating a record-high bunch charge (above 4 nC). We give short description of the system and then detail our experimental results.