Molecular dynamics in attosecond-duration intense-field pulses using a tandem accelerator

Abstract

External perturbation of intramolecular electric fields can result in structural changes that influence energy, entropy and molecular dynamics. We have probed the ionization and fragmentation dynamics of triatomic and polyatomic molecules induced by intense, transient fields generated in fast (50-100 MeV) collisions with Si^q+ (q=3-8) ions, and by using a laser. In the former case, at an impact parameter of ~3Å , the target molecule experiences an attosecond-duration field whose magnitude (~0.05 V/Å) matches that induced by intense (10¹³ W/cm²) laser light. The temporal and directional properties of the two fields are very different: the linearly-polarized light yields a fixed field direction whereas the ion-induced field is time-dependent. Moreover, the ion-induced fields are of attosecond duration whereas the laser-induced ones last for picoseconds. We explore how the dissociative ionization patterns measured in our experiments reflect these temporal and directional differences.