Eur. Phys. J. A (2014) 50: 83
https://doi.org/10.1140/epja/i2014-14083-0

Regular Article - Experimental Physics

Photo-neutron reaction cross-sections for ^natZr in the bremsstrahlung end-point energies of 12-16 and 45-70 MeV

¹ Radiochemistry Division, Bhabha Atomic Research Centre, 400085, Mumbai, India
² Department of Physics, Kyungpook National University, 702-701, Daegu, Republic of Korea
³ Institute of Radiation Physics, Helmholtz-Zentrum Dresden-Rossendorf, 01328, Dresden, Germany
⁴ Division of Advanced Nuclear Engineering, Pohang University of Science and Technology, 790-784, Pohang, Republic of Korea

^* e-mail: gnkim@knu.ac.kr

Received: 12 October 2013
Revised: 30 January 2014
Accepted: 11 March 2014
Published online: 9 May 2014

Abstract

The ^natZr(, xn) ^89-86Zr reaction cross-sections were experimentally determined at the bremsstrahlung end-point energies of 12, 14, 16, 45, 50, 55, 60 and 70MeV by activation and off-line -ray spectrometric technique using the 20 MeV electron linac (ELBE) at the Helmholtz-Zentrum Dresden-Rossendorf (HZDR), Dresden, Germany, and the 100 MeV electron linac at the Pohang Accelerator Laboratory (PAL), Pohang, Korea. The ^natZr(, xn) ^89-86Zr reaction cross-sections as a function of photon energy were also calculated using the TALYS 1.4 computer code. The flux-weighted average cross-sections at the end-point energies of 12-16 and 45-70 MeV were obtained using the literature and the TALYS calculation data based on mono-energetic photons and are found to be in good agreement with the present data. It was also found that the present data and the flux-weighted literature and theoretical values for the ^natZr(, xn) ^89-86Zr reaction cross-sections increase from the threshold values to a certain energy, where other reaction channels open. This indicates the role of excitation energy. However, the increasing trend of the ^natZr(, xn) ^89,88Zr reaction cross-sections are sharper from the threshold value up to end-point bremsstrahlung energies of 17-22 MeV compared to the same for the ^natZr(, xn) ^{87, 86}Zr reactions. This is due to the Giant Dipole Resonance (GDR) effect besides the role of excitation energy. After a certain value, the individual ^natZr(, xn) reaction cross-sections decrease with the increase of bremsstrahlung energy due to opening of other reactions, which indicates partitioning of energy in different channels.