Indirect (n, Υ)91,92Zr Cross Section Measurements for the s-Process

Abstract

Nuclear level densities (NLDs) and Υ-ray strength functions (ΥSFs) of 91,92Zr have been extracted from particle-Υ coincidences using the Oslo method. The extracted ΥSF data, combined with photonuclear cross sections, cover the whole energy range from EΥ = 1.5 MeV up�to the giant dipole resonance at EΥ17MeV. The wide-range ΥSF data display structures at EΥ = 9.5 MeV, compatible with a superposition of the spin-flip M1 resonance and a pygmy E1 resonance. Furthermore, the SF shows a minimum at 2–3 MeV and an increase at lower Υ-ray energies. The experimentally constrained NLDs and SFs are shown to reproduce known and Maxwellian-averaged cross sections for Zr using the TALYS reaction code, thus serving as a benchmark for this indirect method of estimating cross sections for Zr isotopes.