title: Angular-momentum evolution in laser-plasma accelerators.
abstract: The transverse properties of an electron beam are characterized by two quantities, the emittance which indicates the electron beam extent in the phase space and the angular momentum which allows for nonplanar electron trajectories. Whereas the emittance of electron beams produced in a laser-plasma accelerator has been measured in several experiments, their angular momentum has been scarcely studied. It was demonstrated that electrons in a laser-plasma accelerator carry some angular momentum, but its origin was not established. Here we identify one source of angular-momentum growth and we present experimental results showing that the angular-momentum content evolves during the acceleration.
authors.affiliation: Laboratoire d'Optique Appliquée, ENSTA ParisTech-CNRS UMR7639-École Polytechnique, Chemin de la Hunière, 91761 Palaiseau, France.
authors.forename: C
authors.initials: C
authors.lastname: Thaury
authors.forename: E
authors.initials: E
authors.lastname: Guillaume
authors.forename: S
authors.initials: S
authors.lastname: Corde
authors.forename: R
authors.initials: R
authors.lastname: Lehe
authors.forename: M
authors.initials: M
authors.lastname: Le Bouteiller
authors.forename: K
authors.initials: K
authors.lastname: Ta Phuoc
authors.forename: X
authors.initials: X
authors.lastname: Davoine
authors.forename: J M
authors.initials: JM
authors.lastname: Rax
authors.forename: A
authors.initials: A
authors.lastname: Rousse
authors.forename: V
authors.initials: V
authors.lastname: Malka