Multiphoton ionisation of H2and D2using an intense sub-picosecond laser

Abstract
The multiphoton ionisation of H2 and D2 has been studied using a laser of focused intensity approximately 1016 W cm-2, wavelength 600 nm and pulse length 0.6 ps. The H+ and D+ energy spectra are very similar, with a peak at 3 eV and maximum at about 6 eV. Mass spectra taken with a laser of identical intensity, wavelength 248 nm and pulse length 5 ps have a similar energy spread. The low energies of ions observed here are in sharp contrast to those of the N2+ and N3+ ions observed previously in N2.
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