CARBON CLUSTER STUDIES USING THE NSC PELLETRON

The cesium sputter negative ion source of the NSC 16 MV Pelletron acce lerator has been used to produce a variety of cluster negative ions. O ne of the various studies that has been carried out is the comparison of the negative cluster ion intensity distribution obtained by sputter ing two different samples of carbon, viz, graphite and amorphous carbo n. The C-n(-) ion intensity distribution as a function of the cluster mass shows some remarkable differences as well as some similarities in the two cases. Most of the observations could be interpreted using ex isting theoretical models. However, a number of observations such as t he intensity distribution of the CsCn- ions, which is totally differen t for the two samples, are still not understood. Some of these cluster s have been accelerated to MeV energies using the Pelletron accelerato r. A calculation of the repulsive Coulomb energies has been performed for charged clusters of various sizes and compared with theoretically calculated values of average binding energies. The highest possible ch arge states that can be expected of some of these clusters have been p redicted and compared with experimental measurements.