Transition from nonsequential to sequential double ionization in many-electron systems

摘要: Understanding strong-field double ionization of many-electron systems is an important fundamental problem with potential implications for molecular imaging within this regime. Using mid-IR radiation, we unambiguously identify the transition from nonsequential ($e, 2e$) to sequential in Xe at intensity below ${10}^{14}\phantom{\rule{0.16em}{0ex}}\mathrm{W}/\mathrm{c}{\mathrm{m}}^{2}$. Ionization excited orbitals found be decisive low intensities, but demonstrate that such mechanisms are unimportant We utilize these facts successfully image a dication using laser-induced electron diffraction. This methodology can used study dynamics on unprecedented few-femtosecond time scales.