Isomeric yield ratios and cross section ratios of the photoproton reactions 96Mo(γ, p)95m,gNb and 98Mo(γ, p)97m,gNb

In the present work results of investigation of the isomeric yield ratios Ym/Yg and cross-section, ratios σm/σg of the photoproton reactions 96Mo(γ, p)95m,gNb and 98Mo(γ, p)97m,gNb in the energy range of 12*35 MeV with energy step of 1 MeV are presented. The isomeric yield ratios were measured by the induced radioactivity method. Samples of natural Mo have been irradiated in the bremsstrahlung beam of the betatron SB-50 of Institute of Applied Physics of National University of Uzbekistan. A device for the intra-chamer bremsstrahlung irradiation of samples in a betatron, combined with a K5-2A pneumotransport system was used in order to increase the density of the bremsstrahlung flux was used. The induced activities were examined by detecting and analyzing γ-rays with help of a 40 cm3 Ge(Li) semiconductor spectrometer equipped with a 4096 channel pulse height analyzer. The counting system had a resolution of ∼3 keV for the 1332 keV γ-line of 60Co. The yields of the metastable state decays were evaluated by using the 235 keV (95mNb, Jπ=l/2-, T1/2=87 h) and 745 keV(97mNb, Jπ=1/2-, T1/2=1m) γ-rays. The yields of the ground state decays were evaluated by using the 766 keV(95gNb, Jπ=9/2+, T1/2=35 d) and 657 keV(97gNb, Jπ=9/2+, T1/2=72,1m) γ-rays. The isomeric yield ratios were determined eq. form ref./3/. The results of calculation are given in the table below (25*30 MeV). For the 98Mo the results are in good agreement with the date of ref. The isomeric yield ratios of the reaction (γ, p) on 96Mo are obtained at first. The results are compared with the calculations made in the statistical Fermi-gas theory. The experimental results are in agreement with the calculated ratios for values of spin cut-off parameter a between 2 and 3.