Femtosecond spectroscopy of molecular autoionization and fragmentation

Femtosecond laser pulses are applied to the study of the dynamics and the pathways of multiphoton-induced ionization, autoionization, and fragmentation of ${\mathrm{Na}}_2$ in molecular-beam experiments. In particular, we report on first results obtained studying electronic autoionization (leading to ${\mathrm{Na}}_2^{+}$+${\mathrm{e}}^{\mathrm{-}}$) and autoionization-induced fragmentation (leading to ${\mathrm{Na}}^{+}$+Na+${\mathrm{e}}^{\mathrm{-}}$) of a bound doubly excited molecular state. The final continuum states are analyzed by photoelectron spectroscopy and by measuring the mass and the released kinetic energy of the corresponding ionic fragments with a time-of-flight arrangement.