The effects of cathode electrodeposited polymer film on the long vacuum gap breakdown Yu Zhang, Jiancang Su, Xudong Qiu, Rui Li, Liang Zhao, Binxiong Yu, Jie Cheng, Bo Zeng and Xiudong Xu Eur. Phys. J. Appl. Phys., 81 2 (2018) 21301 Published online: 08 June 2018 DOI: 10.1051/epjap/2018170306