title: Measurement of the laser-pulse group velocity in plasma waveguides.
abstract: Electrically discharged plasma channels can guide laser pulses, extending the laser-plasma interaction length to many Rayleigh ranges. In applications such as the laser-plasma accelerator, the laser group velocity in the channel plays a critical role. The laser travel time (and thus the averaged group velocity) was measured through two-pulse frequency-domain interferometry and was found to depend on the on-axis plasma density and laser spot size. The data is in agreement with theory.
authors.affiliation: Lawrence Berkeley National Laboratory, University of California, Berkeley, California 94720, USA.
authors.forename: J
authors.initials: J
authors.lastname: van Tilborg
authors.affiliation: Lawrence Berkeley National Laboratory, University of California, Berkeley, California 94720, USA and Eindhoven University of Technology, P.O. Box 513, 5600 MB Eindhoven, The Netherlands.
authors.forename: J
authors.initials: J
authors.lastname: Daniels
authors.affiliation: Lawrence Berkeley National Laboratory, University of California, Berkeley, California 94720, USA.
authors.forename: A J
authors.initials: AJ
authors.lastname: Gonsalves
authors.affiliation: Lawrence Berkeley National Laboratory, University of California, Berkeley, California 94720, USA.
authors.forename: C B
authors.initials: CB
authors.lastname: Schroeder
authors.affiliation: Lawrence Berkeley National Laboratory, University of California, Berkeley, California 94720, USA.
authors.forename: E
authors.initials: E
authors.lastname: Esarey
authors.affiliation: Lawrence Berkeley National Laboratory, University of California, Berkeley, California 94720, USA.
authors.forename: W P
authors.initials: WP
authors.lastname: Leemans
mesh_terms: D007368:Interferometry / Q000295:instrumentation*; D007477:Ions; D007834:Lasers; D058626:Plasma Gases / Q000737:chemistry* / Q000528:radiation effects*; D011829:Radiation Dosage; D012212:Rheology / Q000379:methods*; D012542:Scattering, Radiation; D020349:Surface Plasmon Resonance / Q000295:instrumentation*
chemical_list: D007477:Ions; D058626:Plasma Gases