Measurement of isomeric yield ratios of Pt-197m,Pt-g and Ir-190m2,Ir-g+m1 from the Pt-198(gamma,n) and Pt-nat(gamma,xn1p) reactions induced by 55-, 60-, and 65-MeV bremsstrahlung

Abstract

We have measured the isomeric yield ratios of Pt-197m,Pt-g from the Pt-198(gamma,n) reaction and Ir-190m2,Ir-g+m1 from the Pt-nat(gamma,xn1p) reaction, induced with the bremsstrahlung end-point energies of 55-, 60-, and 65-MeV. The measurements were carried out by the activation method in combination with the direct gamma-spectrometry. The experiments were performed at the 100 MeV electron linac of the Pohang Accelerator Laboratory (PAL). The obtained results at 55-, 60- and 65-MeV for the Pt-197m,Pt-g from the Pt-198(gamma,n) reaction are 0.166 +/- 0.012, 0.174 +/- 0.011, and 0.175 +/- 0.011, whereas for the Ir-190m2,Ir-g+m1 from the Pt-nat(gamma,xn1p) reaction are 0.072 +/- 0.006, 0.084 +/- 0.006 and 0.087 +/- 0.006, respectively. The present results are measured for the first time over the investigated energy range. The present data are compared with the similar literature data at lower energy to examine the role of excitation energy. (C) 2015 Elsevier B.V. All rights reserved.