Femtosecond laser-induced Coulomb explosion of ammonia clusters

Abstract Nitrogen atoms, as highly charged as N 5+ , are found to be formed upon the irradiation of (NH 3 ) n clusters with an intense femtosecond laser beam. Kinetic energy release values of the nitrogen atoms, from the Coulomb explosion of ammonia clusters, are found to be on the order of several hundred electron volts as calculated from the peak splittings, and also directly measured from cutoff potentials using a reflection as an energy analyzer. Also, we observe a Coulomb explosion process which results in the production of intact cluster ions, and we propose a mechanism for their formation.