Ultrahigh-brightness 50 MeV electron beam generation from laser wakefield acceleration in a weakly nonlinear regime oleh Zhongtao Xiang, Changhai Yu, Zhiyong Qin, Xuhui Jiao, Jiahui Cheng, Qiaoxuan Zhou, Gatie Axi, Jianghua Jie, Ya Huang, Jintan Cai, Jiansheng Liu