Over the past 6 years at Queen's University Belfast, we have made considerable strides in solving the fundamental, time-dependent, three-body problem presented by laser-driven helium and, latterly, that which arises in laser-driven H2+ when vibrational dissociation is allowed to take place.
The underlying spirit of our work has been to treat the electronic motion of the systems in full-dimensionality and the nuclear motion in appropriate lower-dimensionality. We are of course interested primarily in those high laser intensity ranges where both electrons of helium can gain enough energy to ionize.
The three primary goals of our integrations of the Time-Dependent Schrödinger Equation (TDSE) have been:
The calculation of intense-field (two-electron) phenomena that no low-dimensionality or ad hoc theory can adequately model. Support for the design of simplified theoretical models (if any) of multi-electron, atom-laser interactions. Support and guidance for laboratory experiment.
In this talk I will report progress in each of these lines of research but will nevertheless concentrate on our latest results. For helium these are at laser wavelengths of 390 nm (where direct comparison with laboratory experiment has been possible) and also for wavelengths around 20 nm where novel ionization mechanisms are found to occur. The latter wavelength range is of particular relevance to laboratory experiments that could exploit the new free-electron-laser source under development in Hamburg.