Coulomb focusing in resonant production of super-ponderomotive photo-electrons from helium

We present wave functions of helium atoms exposed to an intense 800-nm laser, calculated by numerical integration of the time-dependent Schrödinger equation. Around 600 TW/cm² strong resonance enhancements of high-energy electrons occur, each leading to the appearance of specific quasi-periodic charge distribution patterns around the atom. The time-dependence of several such states is presented and discussed.