title: Quasimonoenergetic electrons from unphased injection into channel guided laser wakefield accelerators.
abstract: A high-quality electron beam can be extracted from a channel guided laser wakefield accelerator without confining the injected particles to a small region of phase. By careful choice of the injection energy, a regime can be found where uniformly phased particles are quickly bunched by the accelerator itself and subsequently accelerated to high energy. The process is particularly effective in a plasma channel because of a favorable phase shift that occurs in the focusing fields. Furthermore, particle-in-cell simulations show that the self-fields of the injected bunches actually tend to reduce the energy spread on the final beam. The final beam characteristics can be calculated using a computationally inexpensive Hamiltonian formulation when beam-loading effects are minimal.
authors.affiliation: Naval Research Laboratory, Plasma Physics Division, Washington, D.C. 20375, USA.
authors.forename: D F
authors.initials: DF
authors.lastname: Gordon
authors.forename: R F
authors.initials: RF
authors.lastname: Hubbard
authors.forename: J H
authors.initials: JH
authors.lastname: Cooley
authors.forename: B
authors.initials: B
authors.lastname: Hafizi
authors.forename: A
authors.initials: A
authors.lastname: Ting
authors.forename: P
authors.initials: P
authors.lastname: Sprangle