Systematics of Fission-Product Yields

Empirical equations representing systematics of fission-product yields have been derived from experimental data. The systematics give some insight into nuclear-structure effects on yields, and the equations allow estimation of yields from fission of any nuclide with atomic number Z sub F = 90 thru 98, mass number A sub F = 230 thru 252, and precursor excitation energy (projectile kinetic plus binding energies) PE = 0 thru approx 200 MeV--the ranges of these quantities for the fissioning nuclei investigated. Calculations can be made with the computer program CYFP. Estimates of uncertainties in the yield estimates are given by equations, also in CYFP, and range from approx 15% for the highest yield values to several orders of magnitude for very small yield values. A summation method is used to calculate weighted average parameter values for fast-neutron (approx fission spectrum) induced fission reactions.