Fast-beam study of H-2(+) ions in an intense femtosecond laser field

A fast beam of H-2(+) ions, produced from a low energy ion accelerator, has been used for the first time in intense laser field experiments. The techn ique has enabled neutral dissociation products to be analysed and detected for the first time in such studies. Energy spectra of neutral and ionized f ragments, product yields as a function of focused laser intensity and angul ar distributions of neutral dissociation products have been measured. Signi ficant differences are observed between the present results and those obtai ned from experiments involving neutral H-2 molecules. These differences are indicative of the precursor H-2 molecule playing an important and hitherto neglected formative role in the laser-induced fragmentation processes.