Clusters in the photodisintegration of Be-9

The ground-state cross sections and angular distributions of Be-9( gamma,p) , Be-9(gamma,t), Be-9( gamma, He-3), and Be-9( gamma,d) are reported, toget her with the cross section for the Be-9(gamma,d) reaction to the first exci ted state. Qualitative discussions of these cross sections are made on the basis of a simple model which assumes free clusters in 9Be. This is similar to the two-cluster model used for Li-6 and Li-7 for which theoretical calc ulations have been made. Predictions on the basis of this model indicate th e importance of clustering in the photodisintegration of Be-9, Li-6, and Li -7. The observed angular distributions are consistent with contributions du e to E1 and E2 transitions. [S0556-2813(99)01801-4].