Multipolarity of γ-ray Absorption in U²³⁸(γ, f) Reaction produced by F(p, αγ) γ rays

Abstract

Multipolarity of γ-ray absorption in U²³⁸(γ, f) reaction, produced by monochromatic γ rays from F(p, αγ) reactions, has been investigated by the analysis of the angular distribution of 1018 tracks of fission fragments in uranium-impregnated nuclear emulsions. It can be explained by mixing two sorts of interaction; electric dipole (E1) and electric quadrupole (E2). The ratio of E2 to E1 absorption cross section, denoted by σ_fq⁄σ_fd, has been found to be 0.13±0.05. This value is compared with other results with bremsstrahlung. The angular distribution is consistent with those of Baz et al., however, the analysis and interpretation of the results are different from those of Baz et al..