Isomeric yield ratios of Y-87m,Y-g from different nuclear reactions

Abstract

The independent isomeric yield ratios of Y-87m,Y-g produced from the Nb-93(gamma, alpha 2n) and Zr-nat(gamma, pxn) reactions with the end-point bremsstrahlung energy of 45-70 MeV have been determined by an off-line gamma-ray spectrometric technique using 100 MeV electron linac at the Pohang accelerator laboratory, Korea. The isomeric yield ratios of Y-87m,Y-g were also determined from the Zr-nat(p, alpha xn) and the Y-89(p,p2n) reactions with E (P) = 15-45 MeV as well as those from the Y-89(alpha, alpha 2n) reaction with E (alpha) = 32-43 MeV using the MC-50 cyclotron at the Korea Institute of Radiological and Medical Science, Korea. The isomeric yield ratios of Y-87m,Y-g from the present work in the Nb-93(gamma, alpha 2n), Zr-nat(gamma, pxn), Zr-nat(p, alpha xn), Y-89(p,p2n), and Y-89(alpha, alpha 2n) reactions were compared with those of the literature data in the Rb-85(alpha, 2n), the Sr-86,Sr-87,Sr-88(d, xn), Y-89(n,3n), and the Y-89(gamma, 2n) reactions to examine the role of target, projectiles, and ejectiles through compound nucleus excitation energy and input angular momentum. The isomeric yield ratios of Y-87m,Y-g in the above eleven reactions were also calculated using the computer code TALYS 1.4 and compared with the experimental data. The different behaviors between photon- and neutron-induced reactions and charged-particle-induced reactions are discussed from the viewpoint of compound and non-compound (pre-equilibrium) process.