We show how in molecular predissociation a method combining ultrafast pump-probe techniques with a measurement of the relative recoil velocity can map time-dependent neutral fragment distributions into the ionic continuum. With an appropriate probe pulse exciting a resonant transition (such as (1+1) Resonance Enhanced Multiphoton Ionisation, or excitation of ZEKE states), the temporal evolution of fragment distributions can in principle be measured. Numerical simulations on NaI predissociation are compared to a simple approximate mapping interpretation. The results are discussed in terms of the interplay between temporal and energetic resolution with respect to current experimental limitations.

Eur. Phys. J. D

Degert, J., Meier, C., Girard, B., & Vrakking, M. J. J. (2001). Time-dependent fragment distributions detected via pump-probe ionisation: a theoretical approach. Eur. Phys. J. D, 14, 257–265.