We report the results for the production of highly charged atomic species (e.g., ${\mathrm{Xe}}^{20+},{\mathrm{Kr}}^{18+},{\mathrm{O}}^{5+},$ and ${\mathrm{C}}^{4+}$) resulting from the interaction of intense laser fields (up to $\sim {10}^{15}\mathrm{W}/{\mathrm{cm}}^2$) with atomic and multicenter molecular clusters. The processes are also investigated using ultrafast pump-probe techniques, showing distinct beating patterns for the ionization structure in the molecular system. A comparison of our results with predictions of several different theoretical models provides strong support for the ionization ignition mechanism.

• Received 22 April 1996

DOI:https://doi.org/10.1103/PhysRevLett.77.3347