Isomeric ratio of the 181Ta(γ,3n)178m,gTa reaction products at energy Eγmax up to 95 MeV

The photoneutron reaction¹⁸Ta(y,3m)(178m,g)Ta was investigated with the beam from the NSC KIPT electron linear accelerator LUE-40.The measurements were performed using the residual y-activity method.The bremsstrahlung flux-averaged cross sections((E_γmax)>.(r(E_γmax)>m.γmax)g and the isomerie ratio of the re-action products d(E_γmax)were measured.The theoretical values of the averaged cross-sections and isomeric ratio were calculated using the partial cross-sections from the TALYS1.95 code for different level density models LD 1-6..The obtained experimental d(E_γmax)agree with the data in the lterature,but differ from the theoretical values in ab-solute magnitude and the behavior of the energy dependence.A comparison of the determined averaged cross-sec-tions with the calculated cross sections showed the best agreement for the case of the LD 5 model.