title: Electron emission at locked phases from the laser-driven surface plasma wave.
abstract: By irradiating a flat Al target with femtosecond laser pulses at moderate intensities of ∼10(17)  W/cm(2), we obtained stable collimated quasimonoenergetic electrons in the specular direction but deviated somewhat toward the target normal. An associated local minimum located on the other side of the specular direction seems to indicate that the peak actually results from the deflection of the collimated electrons from their initial ejection direction. We have proposed a two-step model in which some laser-accelerated electrons are able to leave the plasma in a narrow phase-locked window of the moving wave interference pattern, and are then steered toward the target normal by the ponderomotive force of the interference field. The periodic repetition of the electron emission leads to a pulse train of collimated quasimonoenergetic electrons with subcycle duration.
authors.affiliation: State Key Laboratory of High Field Laser Physics, Shanghai Institute of Optics and Fine Mechanics, Chinese Academy of Sciences, Shanghai 201800, China.
authors.forename: Ye
authors.initials: Y
authors.lastname: Tian
authors.forename: Jiansheng
authors.initials: J
authors.lastname: Liu
authors.forename: Wentao
authors.initials: W
authors.lastname: Wang
authors.forename: Cheng
authors.initials: C
authors.lastname: Wang
authors.forename: Aihua
authors.initials: A
authors.lastname: Deng
authors.forename: Changquan
authors.initials: C
authors.lastname: Xia
authors.forename: Wentao
authors.initials: W
authors.lastname: Li
authors.forename: Lihua
authors.initials: L
authors.lastname: Cao
authors.forename: Haiyang
authors.initials: H
authors.lastname: Lu
authors.forename: Hui
authors.initials: H
authors.lastname: Zhang
authors.forename: Yi
authors.initials: Y
authors.lastname: Xu
authors.forename: Yuxin
authors.initials: Y
authors.lastname: Leng
authors.forename: Ruxin
authors.initials: R
authors.lastname: Li
authors.forename: Zhizhan
authors.initials: Z
authors.lastname: Xu