Fission cross sections resulting from a 120 MeV/nucleon ${}_{}{}^{238}{}_{}{}^{}\mathrm{U}$ beam incident upon Be, Al, Cu, Ag, and U targets have recently been measured by Justice et al. [Phys. Rev. C 49, R5 (1994)]. The electromagnetic contribution to these experimental cross sections have been compared to Weizsäcker-Williams theory which is based on first-order perturbation theory. The present work calculates the contribution to these cross sections due to higher-order excitations. Our results show that these corrections are insignificant in comparison to experimental error.

• Received 14 October 1994

DOI:https://doi.org/10.1103/PhysRevC.51.1566