Multiphoton ionization of inner-valence electrons and fragmentation of ethylene in an intense Ti:sapphire laser pulse

Using linearly polarized 200 fs Ti:sapphire laser pulses the multiphoton ionization and fragmentation of ethylene was studied. A model is proposed which is able to satisfactorily predict the abundance of the different fragments, C2H4+, C2H3+ and C2H2+ as a function of laser intensity. It is shown that fragmentation of the molecule occurs as a result of multiphoton ionization of inner-valence electrons followed by radiationless transitions to various dissociation channels of the molecular ion.