title: Enhanced single-stage laser-driven electron acceleration by self-controlled ionization injection.
abstract: We report on overall enhancement of a single-stage laser wakefield acceleration (LWFA) using the ionization injection in a mixture of 0.3% nitrogen gas in 99.7% helium gas. Upon the interaction of 30-TW, 30-fs laser pulses with a gas jet of the above gas mixture, >300 MeV electron beams were generated at a helium plasma densities of 3.3-8.5 × 10(18) cm(-3). Compared with the uncontrolled electron self-injection in pure helium gas jet, the ionization injection process due to the presence of ultra-low nitrogen concentrations appears to be self-controlled; it has led to the generation of electron beams with higher energies, higher charge, lower density threshold for trapping, and a narrower energy spread without dark current (low energy electrons) or multiple bunches. It is foreseen that further optimization of such a scheme is expected to bring the electron beam energy-spread down to 1%, making them suitable for driving ultra-compact free-electron lasers.
authors.forename: Song
authors.initials: S
authors.lastname: Li
authors.forename: Nasr A M
authors.initials: NA
authors.lastname: Hafz
authors.forename: Mohammad
authors.initials: M
authors.lastname: Mirzaie
authors.forename: Thomas
authors.initials: T
authors.lastname: Sokollik
authors.forename: Ming
authors.initials: M
authors.lastname: Zeng
authors.forename: Min
authors.initials: M
authors.lastname: Chen
authors.forename: Zhengming
authors.initials: Z
authors.lastname: Sheng
authors.forename: Jie
authors.initials: J
authors.lastname: Zhang
mesh_terms: D004583:Electrons; D007477:Ions; D007834:Lasers; D058626:Plasma Gases / Q000737:chemistry; D013816:Thermodynamics
chemical_list: D007477:Ions; D058626:Plasma Gases