Different empirical and semiempirical systematics have been developed to predict unmeasured fission product yields. One of these methods, originally proposed by Musgrove et al. and developed by Cook et al. , is used to describe the energy dependence of the mass distribution in neutron-induced fission of **2**3**8U utilizing published yield data. The available measured cumulative yields of fission products are collected for monoenergetic **2**3**8U(n,f) processes. The mass distributions at approximate neutron energies of 1. 5, 2. 0, 3. 0, 3. 9, 5. 2, 6. 0, 7. 0, 7. 9, 9. 0, and 14. 7 Mev are fitted by the sum of five Gaussian functions. The energy dependence of the parameters of the Gaussian functions can also be described by semiempirical formulas. The 2 sigma error of the mass yields calculated by the fitted parameters can be estimated to be approx. 10% in the peak regions and 20% in the valley region for the above neutron energies. The formulas with the given parameters can be useful in estimating unmeasured **2**3**8U fission product yields for any monoenergetic and nonmonoenergetic neutron irradiations in the range of 1. 5 to 15 Mev. The method has been tested in a study of the **2**3** 8U fission by neutrons having a Watt spectrum produced in the thermal fission of **2**3**5U.
ASJC Scopus subject areas
- Nuclear Energy and Engineering