title: Laser-driven coherent betatron oscillation in a laser-wakefield cavity.
abstract: The origin of beam disparity in emittance and betatron oscillation orbits, in and out of the polarization plane of the drive laser of laser-plasma accelerators, is explained in terms of betatron oscillations driven by the laser field. As trapped electrons accelerate, they move forward and interact with the laser pulse. For the bubble regime, a simple model is presented to describe this interaction in terms of a harmonic oscillator with a driving force from the laser and a restoring force from the plasma wake field. The resulting beam oscillations in the polarization plane, with period approximately the wavelength of the driving laser, increase emittance in that plane and cause microbunching of the beam. These effects are observed directly in 3D particle-in-cell simulations.
authors: Accelerator Systems Division, Argonne National Laboratory, Argonne, IL 60439, USA. Nemeth@ANL.Gov
authors: Károly
authors: K
authors: Németh
authors: Baifei
authors: B
authors: Shen
authors: Yuelin
authors: Y
authors: Li
authors: Hairong
authors: H
authors: Shang
authors: Robert
authors: R
authors: Crowell
authors: Katherine C
authors: KC
authors: Harkay
authors: John R
authors: JR
authors: Cary