title: Generation of quasi-monoenergetic electron beams with small normalized divergences angle from a 2 TW laser facility.
abstract: We report the generation of a 6 pC, 23 MeV electron bunch with the energy spread ± 3.5% by using 2 TW, 80 fs high contrast laser pulses interacting with helium gas targets. Within the optimized experimental condition, we obtained quasi-monoenergetic electron beam with an ultra-small normalized divergence angle of 92 mrad, which is at least 5 times smaller than the previous LPA-produced bunches. We suggest the significant decrease of the normalized divergence angles is due to smooth transfer from SM-LWFA to LWFA. Since the beam size in LPA is typically small, this observation may explore a simple way to generate ultralow normalized emittance electron bunches by using small-power but high-repetition-rate laser facilities.
authors.forename: D Z
authors.initials: DZ
authors.lastname: Li
authors.forename: W C
authors.initials: WC
authors.lastname: Yan
authors.forename: L M
authors.initials: LM
authors.lastname: Chen
authors.forename: K
authors.initials: K
authors.lastname: Huang
authors.forename: Y
authors.initials: Y
authors.lastname: Ma
authors.forename: J R
authors.initials: JR
authors.lastname: Zhao
authors.forename: L
authors.initials: L
authors.lastname: Zhang
authors.forename: N
authors.initials: N
authors.lastname: Hafz
authors.forename: W M
authors.initials: WM
authors.lastname: Wang
authors.forename: J L
authors.initials: JL
authors.lastname: Ma
authors.forename: Y T
authors.initials: YT
authors.lastname: Li
authors.forename: Z Y
authors.initials: ZY
authors.lastname: Wei
authors.forename: J
authors.initials: J
authors.lastname: Gao
authors.forename: Z M
authors.initials: ZM
authors.lastname: Sheng
authors.forename: J
authors.initials: J
authors.lastname: Zhang