CLUSTER-IMPACT FUSION AND CLUSTER-SIZE DISTRIBUTIONS

D + D fusion yields have been measured for small deuterated molecules incident on deuterated polyethylene and are one to two orders of magnitude smaller than previously reported by another group. They are, however, in good agreement with free-particle cross sections. Fusion has also been observed for pure carbon clusters incident on deuterated polyethylene. Comparison of fusion yields per carbon for clusters and single carbon atoms show no collective enhancements. The observed fusion for carbon clusters is shown to be due to a knock on mechanism. Cluster size distributions for graphite sputtered with cesium exhibit a rich periodic structure whose origin will be discussed in terms of molecular orbital theory.