Fusion Enery--frontiers Hot electrons can be generated in the laser focal spot and escape from the surface,which may carry i important information to understand some specific physical processes regarding laser and target interactions in ICF. e>eΦ Target ax electrostatic spot radius Φ→0 OA aA R,electron cloud radius 8t 000 E Rfocal spot radius Φ=const E i-×=-器 E Target surfaceFusion Enery--frontiers Hot electrons can be generated in the laser focal spot and escape from the surface, which may carry important information to understand some specific physical processes regarding laser and target interactions in ICF