Does the coherent bremsstrahlung of fission fragments exist?

The spectrum of γ rays from the neutron-induced fission of ²³⁵U nuclei has been studied in a range of 10–90 MeV. The experiment has been carried out in the horizontal experimental channel of a nuclear reactor. The energy spectrum was measured using a single-crystal NaI(T1) spectrometer. The data on the energy dependence of the yield of γ rays have been obtained in a range of 12–38 MeV. The upper limit on the probability of the emission of γ rays has been determined for a range of 38–90 MeV. It has been shown that the experimental data are inconsistent with available models attributing the yield of γ rays in this energy range to the coherent bremsstrahlung of fission fragments in the Coulomb field.