title: Collective Deceleration of Laser-Driven Electron Bunches.
abstract: Few-fs electron bunches from laser wakefield acceleration (LWFA) can efficiently drive plasma wakefields (PWFs), as shown by their propagation through underdense plasma in two experiments. A strong and density-insensitive deceleration of the bunches has been observed in 2 mm of 10^{18}  cm^{-3} density plasma with 5.1  GV/m average gradient, which is attributed to a self-driven PWF. This observation implies that the physics of PWFs, usually relying on large-scale rf accelerators as drivers, can be studied by tabletop LWFA electron sources.
authors.affiliation: Max-Planck Institut für Quantenoptik, 85748 Garching, Germany.|Department für Physik, Ludwig-Maximilians Universität, 85748 Garching, Germany.
authors.forename: S
authors.initials: S
authors.lastname: Chou
authors.affiliation: Max-Planck Institut für Quantenoptik, 85748 Garching, Germany.|State Key Laboratory of High Field Laser Physics, Shanghai Institute of Optics and Fine Mechanics, Chinese Academy of Sciences, P. O. Box 800-211, Shanghai 201800, China.
authors.forename: J
authors.initials: J
authors.lastname: Xu
authors.affiliation: Department für Physik, Ludwig-Maximilians Universität, 85748 Garching, Germany.
authors.forename: K
authors.initials: K
authors.lastname: Khrennikov
authors.affiliation: Max-Planck Institut für Quantenoptik, 85748 Garching, Germany.|Department für Physik, Ludwig-Maximilians Universität, 85748 Garching, Germany.
authors.forename: D E
authors.initials: DE
authors.lastname: Cardenas
authors.affiliation: Department für Physik, Ludwig-Maximilians Universität, 85748 Garching, Germany.
authors.forename: J
authors.initials: J
authors.lastname: Wenz
authors.affiliation: Department für Physik, Ludwig-Maximilians Universität, 85748 Garching, Germany.
authors.forename: M
authors.initials: M
authors.lastname: Heigoldt
authors.affiliation: Max-Planck Institut für Quantenoptik, 85748 Garching, Germany.|Department für Physik, Ludwig-Maximilians Universität, 85748 Garching, Germany.
authors.forename: L
authors.initials: L
authors.lastname: Hofmann
authors.affiliation: Max-Planck Institut für Quantenoptik, 85748 Garching, Germany.|Department of Physics, Umeå University, SE-901 87 Umeå, Sweden.
authors.forename: L
authors.initials: L
authors.lastname: Veisz
authors.affiliation: Max-Planck Institut für Quantenoptik, 85748 Garching, Germany.|Department für Physik, Ludwig-Maximilians Universität, 85748 Garching, Germany.
authors.forename: S
authors.initials: S
authors.lastname: Karsch