Subjects of research: isomeric states of atomic nuclei with 110 < A < 144
Purpose of the work: To receive new experimental data about relative probability of excitation of isomeric states of nuclei with 110 < A < 144 in photonuclear and neutron reactions in the 10-35 MeV energy range.
Methods of research: The induced radioactivity method, method of monitors.
The results obtained and their novelty: The isomeric yield ratios and cross sections ratios of the (y,n) and (n,2n) reactions on nuclei of ll()Pd, 120'I22'124-128'130'pe) l42Nd, and l44Sm are measured by the induced radioactivity method. The energy dependence of the isomeric yield ratios of the photonuclear reactions ll0Pd(y,n)l09mgPd, 142Nd(y,n) 141m,8Nd, and l44Sm(y,n)143mgSm is investigated in the energy range 14-35 MeV with energy step of 1 MeV. The energy dependence of isomeric yield ratios of the ll0Pd(y,n)l09m’8Pd, l42Nd(y,n) l4lmgNd, and l44Sm(y,n)l43mgSm, was determined for the first time in the range of excitation energies higher than giant dipole resonance (i.e., in the 21-35 MeV range). The measurement results showed that values of the isomeric yield ratio Ут/Yg rose from the reaction’s threshold to the energy corresponding to the position of the maximum of the giant dipole resonance, Em. The function d(EymaK) = Tni/Tg for energies higher than Em has the form of saturation curve. The experimental values of the isomeric integral cross sections ratios photonuclear reactions ll6Cd(y,n)ll5mgCd, l34Ba(y,n)l33mgBa, 136Ba(y,n)135mgBa, 138Ba(y,n)l37mgBa and 138Ce(y,n)137mgCe have been measured for the first time at maximum bremsstrahlung 30 MeV.
Practical value: The received results can be used at studying the mechanism nuclear reactions and also for an estimation of basic possibilities of the gamma activation analysis and by working out of new concrete techniques of the analysis and planning of experiments.
Degree of embed and economic effectively: Results of researches can be use at working out of a technique multielement scale and neutron activation the analysis of various objects.
Field of application: nuclear physics, applied nuclear physics, gamma-activation analysis.
