ACCELERATION OF AUN CLUSTERS TO MEV ENERGIES

Gold clusters Au, with n less-than-or-equal-to 5 and masses m less-than-or-equal-to 985 u have been accelerated to MeV energies with the tandem accelerators at Orsay and Erlangen. Singly charged negative cluster ions were obtained from a conventional sputter ion source and accelerated between ground potential at the entrance of the accelerator and the terminal (in the middle) at several MV. In a gas channel positioned in the terminal they lose one or several electrons and become neutral or positively charged clusters, respectively. The ions are then accelerated towards the exit of the tandem accelerator. Identification of Au(n)+ clusters is achieved by measuring the time-of-flight of the clusters.