Extraction of molecular dynamics in intense laser fields from mass-resolved momentum imaging maps: application to Coulomb explosion of NO

The nuclear dynamics of NO in intense laser fields (~1.4 PW cm -2 ) is studied on the basis of the momentum-scaled time-of-flight spectra and mass-resolved momentum imaging maps of the atomic fragment ions, N p + and O q + ( p , q = 1-3), produced from the ( p , q ) Coulomb explosion pathways of NO, i.e. NO ( p + q )+ N p + +O q + . A procedure to extract nuclear dynamics from the momentum maps is proposed by taking account of the effect of the finite detector size. The resultant nine ( p , q ) single-pathway components show that (a) the distributions of the N-O internuclear distance of NO z + just before the Coulomb explosion exhibit significant broadening (~1 Å); (b) the distance at which the corresponding distribution takes a maximum increases from 1.68 to 2.34 Å as z increases from 2 to 6 with a small amount of suppression at odd z ( z = 3,5); and (c) the atomic fragment ions exhibit narrower angular distributions for a larger total charge z ( = p + q ) of NO z + .