Single and multiple ionization of N2 molecules by intense light fields of femtosecond duration

We report studies on the multiple ionization of the N-2 molecule using intense, femtosecond laser pulses. We present details of the experimental characterisation of the light pulses and analysis and detection of the ions produced. Precautions to be taken in intense field ionization experiments are discussed. We illustrate the retrieval of information about different aspects of the ionization process (such as, kinetic energies of the fragments produced, dissociation bond lengths and information on the precursors to fragmentation) using coincidence techniques. We report results of the first measurements of the angular distribution of a highly charged fragment, N3+.