A simple model is proposed to examine the isotopic yields of the fragments from binary fission. For a given charge partition the peaks and widths in the isotope distributions are studied both with the liquid-drop model and with shell modifications. The basis for isoscaling is also explored. The symmetry energy plays a dominant role in both the distributions and the isoscaling behavior. A systematic increase in the isoscaling parameter $\alpha$ with the proton number of the fragment element is predicted in the context of the liquid-drop model. Deviations arising from shell corrections are explored.

• Received 21 November 2003

DOI:https://doi.org/10.1103/PhysRevC.69.031601