DEFORMATION ON ISOMERIC EXCITATION OF EU ISOTOPES IN (GAMMA,N) AND (N,GAMMA) REACTIONS

Isomeric ratios in (n,gamma) and (gamma,n) reactions in Eu isotopes we re measured. Thermal neutrons and bremsstrahlung photons in the giant dipole resonance energy range of 13-22 MeV were used to excite the iso meric states. The isomeric levels 0(-) and 8(-) were excited in the is otopes Eu-150, Eu-152, and Eu-154. The cross section for the reaction (gamma,n) leading to the high-spin isomeric state 8(-) on Eu-152(m2) i sotope was measured in the giant-dipole-resonance region by the activa tion method. Experimental values of the isomeric cross section ratios were compared with the theoretical values. The influence of the nuclei quadropole deformation on the isomeric ratio was described. [S0556-28 13(98)03011-8].