Doerner, R | Search NASA

DOE OSTI2011

Strong Field Electron Emission from Fixed in Space H{sub 2}{sup +} Ions

We have studied electron emission from the H{sub 2}{sup +} ion by a circularly polarized laser pulse (800 nm, 6x10{sup 14} W/cm{sup 2}). The electron momentum distribution in the body fixed frame of the molecule is experimentally obtained by a coincident detection of electrons and protons. The data are compared to a solution of the time-dependent Schroedinger equation in two dimensions. We find radial and angular distributions which are at odds with the quasistatic enhanced ionization model. The unexpected momentum distribution is traced back to a complex laser-driven electron dynamics inside the molecule influencing the instant of ionization and the initial momentum of the electron.

71 CLASSICAL AND QUANTUM MECHANICS, GENERAL PHYSIC↗

DOE OSTI2011

Probing Angular Correlations in Sequential Double Ionization

We study electron correlation in sequential double ionization of noble gas atoms and HCl in intense, femtosecond laser pulses. We measure the photoelectron angular distributions of Ne{sup +} relative to the first electron in a pump-probe experiment with 8 fs, 800 nm, circularly polarized laser pulses at a peak intensity of a few 10{sup 15} W/cm{sup 2}. Using a linear-linear pump-probe setup, we further study He, Ar, and HCl. We find a clear angular correlation between the two ionization steps in the sequential double ionization intensity regime.

71 CLASSICAL AND QUANTUM MECHANICS, GENERAL PHYSIC↗