DOI: 10.1140/epjd/e2003-00272-8 THE EUROPEAN PHYSICAL JOURNAL D Photoionization of helium with ultrashort XUV laser pulses

Abstract. Coupled-channel calculations for multiphoton ionization probabilities of helium through inter-action with intensive short laser pulses are presented. Besides Slater-like orbitals we use regular Coulomb wavepackets in our configurational interaction basis to describe the continuum. Linearly polarized laser pulses of 3.8 fs duration and 2.96 × 1014 Wcm−2 peak intensity have been used for frequencies between 0.2−1.2 a.u. The results are compared with other ab initio calculations. PACS. 32.80.Fb Photoionization of atoms and ions – 32.80.Wr Other multiphoton processes