Fission channels of multiply charged sodium clusters near the Rayleigh limit - art. no. 051201

Fission of multiply charged sodium clusters Na-n(q+) produced in collisions of neutral clusters with protons at 20 keV is investigated with an event-b y-event acquisition technique. The analysis of fragment correlations shows that clusters undergo a strongly asymmetrical binary fission with Na+, Na-2 (+), Na-3(+), Na-4(+), and Na-5(+) as the small fragments, Na-3(+) dominati ng with approximately 70%, For a given charge q, the branching ratio of Na- 3(+) over Na+ emission increases with n, which is interpreted in terms of a decreasing temperature of the parent cluster following proton impact.