Laboratoire Collisions Agrégats Réactivité - UMR5589

Université Paul Sabatier - Bat. 3R1b4 - 118 route de Narbonne 31062 Toulouse Cedex 09, France

Above threshold ionization in a strong dc electric field

High-lying Rydberg states of Xe have been ionized using intense 108 mm radiation from a Free-Electron Laser (FEL). Measured angle-resolved photoelectron spectra reveal significant above-threshold ionization (ATI) and contain an indirect contribution resulting from the combined action of the atomic Coulomb field, the laser field and the DC electric field of the spectrometer on the electron. Numerical calculations relate the observation of indirect ionization to the multi-photon and tunneling/over-the-barrier regimes of strong-field ionization.

Voir en ligne : Phys. Rev. A 78, 013413 (2008)