Quasi-monoenergetic Electron Beams from Laser-plasma Acceleration by   Ionization-induced Injection in Low- density Pure Nitrogen
  We report a laser wakefield acceleration of electron beams up to 130 MeV from laser-driven 4-mm long nitrogen gas jet. By using a moderate laser intensity (3.5*10^18 W.cm^(-2)) and relatively low plasma densities (0.8*10^18 cm^(-3) to 2.7*10^18 cm^(-3)) we have achieved a stable regime for laser propagation and consequently a stable generation of electron beams. We experimentally studied the dependence of the drive laser energy on the laser-plasma channel and electron beam parameters. The quality of the generated electron beams is discussed within the framework of the ionization-induced injection mechanism. 
Mengze Tao, Nasr A. M. Hafz, Song Li, Mohammad Mirzaie, Liming Chen,   Fei He, Ya Cheng, and Jie Zhang
physics.plasm-ph