Cross Section Measurements and Theoretical Study of the ^174,176Hf(n,2n)^173,175Hf Reactions

¹ Department of Physics, National Technical University of Athens, Zografou campus, 15780 Athens, Greece
² Institute of Nuclear and Radiological Sciences, Energy, Technology & Safety, NCSR Demokritos
³ Institute of Nanoscience and Nanotechnology, NCSR Demokritos
⁴ Department of Naval Architecture, University of West Attica, 122 10 Athens, Greece
⁵ Tandem Accelerator Laboratory, Institute of Nuclear Physics, N.C.S.R. “Demokritos”, Aghia Paraskevi, 15310 Athens, Greece

Published online: 26 May 2023

Abstract

Experimental cross section measurements for the ¹⁷⁶Hf(n,2n)¹⁷⁵Hf and ¹⁷⁴Hf(n,2n)¹⁷³Hf reactions were carried out, using the activation technique. The neutron beam energy in the range of 15.3-20.3 MeV was produced via the ³H(d,n)⁴He reaction at the 5.5 MeV Tandem Van de Graaf accelerator laboratory of NCSR “Demokritos”. A thin metallic foil of natural Hf was used, while for the determination of the neutron flux at the target position, reference foils of Al were placed at the front and back of the Hf target. The irradiations were continuous for ~24-48 hours, leading to a total neutron fluence of 10¹⁰-10¹¹ n/cm² and a BF₃ detector was used for monitoring the neutron flux during the irradiations. After the end of each irradiation, the activity of the Hf target and the Al reference foils were measured off-line by two HPGe detectors. The ¹⁷⁶Hf(n,2n)¹⁷⁵Hf reaction has been corrected for the contribution of the ¹⁷⁷Hf(n,3n)¹⁷⁵Hf and ¹⁷⁴Hf(n,γ)¹⁷⁵Hf reactions. Statistical model calculations based on the Hauser-Feshbach theory have also been performed using the EMPIRE 3.2.3 code. The predictions have been compared with the data of the present work as well as with data from literature.