Dissociative double photoionization of benzene molecules in the 26-33 eV energy range

A time-of-flight mass spectrometer has been used to study the dissociative double ionization of benzene by UV synchrotron radiation. The threshold energy for the main dissociative processes, leading to CH3 + + C5H3 +, C2H3 + + C4H3 + and C2H2 + + C4H4 + ion pairs have been characterized by exploiting a photoelectron-photoion-photoion-coincidence technique, giving 27.8 ± 0.1, 29.5 ± 0.1, and 30.2 ± 0.1 eV, respectively. Theoretical calculations of the energy and structure of dissociation product ions have been also performed to provide further information about the dynamics of these processes