title: Towards non-sequential double ionization of Ne and Ar using a femtosecond laser oscillator.
abstract: We report on first proof-of-principles results on non-sequential double ionization of argon and neon achieved by using a newly developed long-cavity Ti:sapphire femtosecond oscillator with a pulse duration of 45 fs and a repetition of 6.2 MHz combined with a dedicated reaction microscope. Under optimized experimental conditions, peak intensities larger than 2.310(14) W/cm(2) have been achieved. Ion momentum distributions were recorded for both rare gases and show significantly different features for single as well as for double ionization. For single ionization of neon a spike of zero-momentum electrons is found when decreasing the laser intensity towards the lowest ionization rate we can measure which is attributed to a non-resonant ionization channel. As to double ionization, the longitudinal momentum distribution for Ne(2+) displays a clear double-hump structure whereas this feature is found to be smoothened out with a maximum at zero momentum for Ar(2+).
authors: Max-Planck-Institut für Kernphysik, Saupfercheckweg 1, 69117 Heidelberg, Germany. Yunquan.Liu@mpi-hd.mpg.de
authors: Yunquan
authors: Y
authors: Liu
authors: Sebastian
authors: S
authors: Tschuch
authors: Martin
authors: M
authors: Dürr
authors: Artem
authors: A
authors: Rudenko
authors: Robert
authors: R
authors: Moshammer
authors: Joachim
authors: J
authors: Ullrich
authors: Martin
authors: M
authors: Siegel
authors: Uwe
authors: U
authors: Morgner
mesh_terms: D001128:Argon / Q000737:chemistry* / Q000528:radiation effects*; D007477:Ions; D007834:Lasers; D009356:Neon / Q000737:chemistry* / Q000528:radiation effects*; D009991:Oscillometry / Q000295:instrumentation*
chemical_list: D007477:Ions; D009356:Neon; D001128:Argon