FISSION-LIKE DISSOCIATION OF DOUBLY CHARGED SILVER CLUSTERS

The dissociation patterns of doubly charged silver clusters (Ag)2+n to singly charged clusters (Ag)+m have been investigated. They were produced by the Xe+ ion bombardment of a silver sheet and were mass-analyzed using a double focusing mass spectrometer; the resulting ion intensity was < 1% of that of singly charged clusters. The daughter ions, the size of which is larger than n/2, were detected without the interface from those decaying from singly charged clusters by lowering the acceleration voltage below the normal value. The decomposition probabilities as a function fo m-value had a tendency to increase as the difference between m-values and n/2 decreased. Superimposed on the increase, an enhanced ion intensity at certain m-values and an odd-even alternation were observed in which the intensity of odd-m clusters was larger than that of even-m. © 1990.