title: All-optical cascaded laser wakefield accelerator using ionization-induced injection.
abstract: We report on near-GeV electron beam generation from an all-optical cascaded laser wakefield accelerator (LWFA). Electron injection and acceleration are successfully separated and controlled in different LWFA stages by employing two gas cells filled with a He/O2 mixture and pure He gas, respectively. Electrons with a Maxwellian spectrum, generated from the first LWFA assisted by ionization-induced injection, were seeded into the second LWFA with a 3-mm-thick gas cell and accelerated to be a 0.8-GeV quasimonoenergetic electron beam, corresponding to an acceleration gradient of 187  GV/m. The demonstrated scheme paves the way towards the multi-GeV laser accelerators.
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: J S
authors.initials: JS
authors.lastname: Liu
authors.forename: C Q
authors.initials: CQ
authors.lastname: Xia
authors.forename: W T
authors.initials: WT
authors.lastname: Wang
authors.forename: H Y
authors.initials: HY
authors.lastname: Lu
authors.forename: Ch
authors.initials: Ch
authors.lastname: Wang
authors.forename: A H
authors.initials: AH
authors.lastname: Deng
authors.forename: W T
authors.initials: WT
authors.lastname: Li
authors.forename: H
authors.initials: H
authors.lastname: Zhang
authors.forename: X Y
authors.initials: XY
authors.lastname: Liang
authors.forename: Y X
authors.initials: YX
authors.lastname: Leng
authors.forename: X M
authors.initials: XM
authors.lastname: Lu
authors.forename: C
authors.initials: C
authors.lastname: Wang
authors.forename: J Z
authors.initials: JZ
authors.lastname: Wang
authors.forename: K
authors.initials: K
authors.lastname: Nakajima
authors.forename: R X
authors.initials: RX
authors.lastname: Li
authors.forename: Z Z
authors.initials: ZZ
authors.lastname: Xu