Stellar 30-keV neutron capture in 94, 96Zr and the [formula omitted] photonuclear reaction with a high-power liquid-lithium target.

A high-power Liquid-Lithium Target (LiLiT) was used for the first time for neutron production via the thick-target Li 7 ( p , n ) Be 7 reaction and quantitative determination of neutron capture cross sections. Bombarded with a 1–2 mA proton beam at 1.92 MeV from the Soreq Applied Research Accelerator Facility (SARAF), the setup yields a 30-keV quasi-Maxwellian neutron spectrum with an intensity of 3– 5 × 10 10 n / s , more than one order of magnitude larger than present near-threshold Li 7 ( p , n ) neutron sources. The setup was used here to determine the 30-keV Maxwellian averaged cross section (MACS) of 94 Zr and 96 Zr as 28.0 ± 0.6 mb and 12.4 ± 0.5 mb respectively, based on activation measurements. The precision of the cross section determinations results both from the high neutron yield and from detailed simulations of the entire experimental setup. We plan to extend our experimental studies to low-abundance and radioactive targets. In addition, we show here that the setup yields intense high-energy (17.6 and 14.6 MeV) prompt capture γ rays from the Li 7 ( p , γ ) Be 8 reaction with yields of ∼ 3 × 10 8 γ s − 1 mA − 1 and ∼ 4 × 10 8 γ s − 1 mA − 1 , respectively, evidenced by the Zr 90 ( γ , n ) Zr 89 photonuclear reaction. [ABSTRACT FROM AUTHOR]