Experimental study of structure in enhanced ionization of H$_{2}^{+}$ in intense ultrashort laser pulses

Charge resonance enhanced ionization (CREI) of H$_{2}^{+}$ in intense ultrashort laser pulses was measured using molecular dissociation imaging of an H$_{2}^{+}$ beam and with a pump-probe technique using COLTRIMS on an H$_{2}$ target. The dependence of the ionization probability on the internuclear distance is determined independently from both measurements using a simple model for the initial dissociation step. Both data sets lead to a similar R-dependence which indicates that ionization is enhanced at large internuclear distances as predicted by theory [1]. However, in contrast to the predictions for a double peak structure, only one broad peak is observed. [1] T. Zuo and A.D. Bandrauk, Phys. Rev. A \textbf{52}, R2511 (1995)