An empirical parametrization for the production cross sections of ${}^{238}\mathrm{U}$ photofission fragments at low energies ($E_{\gamma }<30$ MeV) is developed. This parametrization, $\mathrm{GIF}{}^{238}\mathrm{U}$, consists of three parts, namely, the photofission cross section, the mass yield, and the isobaric charge distribution. The photofission cross section is parametrized to reproduce measured data over a wide energy range. The mass yield distribution is described by the energy-dependent multimodal fission model. The isobaric charge distribution is improved, relative to other parametrizations, to describe many experimental data sets over a broad mass range. Comparisons with different measured ${}^{238}\mathrm{U}$ photofission data sets at various energies reveal that $\mathrm{GIF}{}^{238}\mathrm{U}$ is in very good agreement with measured elemental and mass yields and can accurately reproduce experimental isotopic yields. Production cross sections (yields) of photofission fragments calculated by this parametrization indicate that many neutron-rich nuclei approaching the $r$-process path can be accessed via photofission of ${}^{238}\mathrm{U}$ at radioactive-beam facilities.

• Received 10 August 2017
• Revised 30 October 2017

DOI:https://doi.org/10.1103/PhysRevC.96.064610