Measurement of isomeric ratios for 89g,m-Zr, 91g,m-Mo, and 97g,m-Nb in the bremsstrahlung end-point energies of 16 and 45–70MeV

Abstract

The independent isomeric yield ratios of Zr-89g,Zr-m from the Zr-nat(,xn) reactions and those of Mo-91g,Mo- m and Nb-97g,Nb-m from the Mo-nat(,x) reactions with the bremsstrahlung end-point energy of 45-70 MeV were determined by an off-line -ray spectrometric technique using the 100 MeV electron linac at the Pohang Accelerator Laboratory, Korea. The isomeric yield ratios of Zr-89g,Zr-m and Nb-97g,Nb-m from the Zr-nat(, xn) and Mo-nat(,x) reactions at the bremsstrahlung end-point energy of 16MeV were also determined by the same technique using the 20MeV electron linac at Helmholtz-Zentrum Dresden-Rossendorf, Germany. The measured isomeric yield ratios of Zr-89g,Zr-m, Mo-91g,Mo-m, and Nb-97g,Nb-m were compared with literature data to examine the role of the Giant Dipole Resonance (GDR). The isomeric yield ratios of the Zr-89g,Zr-m, Mo-91g,Mo-m, and Nb-97g,Nb-m from the above reactions were also calculated by using the computer code TALYS 1.6 and compared with the experimental data to examine the validity of the theoretical model for independent isomeric yield ratio calculations.