AI 中文总结
本研究测量了 $^{65}$Cu($\alpha,n)^{68}$Ga 近阈值厚靶产额，发现与叠箔法结果差异大，并与 IAEA 估计在 8 MeV 处相差近 4 倍，但验证了探测器本底和核合成反应率估计。
AI 中文摘要
我们报告了在俄亥俄大学爱德华兹加速器实验室通过中子计数测量的 $\alpha$ 能量 $E_{\alpha}$$=$6.5--8~MeV 下 $^{65}{\rm Cu}(\alpha,n)^{68}{\rm Ga}$ 的厚靶产额。我们的结果与基于单箔辐照的先前结果一致，但与基于叠箔辐照推断的厚靶产额相差高达一个数量级。基于我们和先前测量与 Hauser-Feshbach 计算的比较，我们估计 $E_{\alpha}$=14~MeV 的 $\alpha$ 粒子轰击 100% 富集铜（$^{65}{\rm Cu}$）时 $^{68}{\rm Ga}$ 的厚靶产额为 161$^{+5}_{-24}$~MBq/$\mu$Ah（对于 He$^{++}$），这与当前 IAEA 估计的 156~MBq/$\mu$Ah 一致。在 $E_{\alpha}$$=$8~MeV 时，使用天然铜靶可实现无放射性杂质生产 $^{68}{\rm Ga}$，我们的产额估计比 IAEA 估计低近 4 倍。我们发现，目前用于中微子和暗物质探测器本底的 $^{65}{\rm Cu}(\alpha,n)$ 截面估计以及最近推荐用于核合成计算的 $^{65}{\rm Cu}(\alpha,n)$ 天体物理反应率与我们的测量结果一致。
英文摘要
We report thick target yields of $^{65}{\rm Cu}(α,n)^{68}{\rm Ga}$ from $α$ energies $E_α$$=$6.5--8~MeV measured via neutron-counting at the Edwards Accelerator Laboratory at Ohio University. Our results agree with prior results based on single-foil irradiations, while disagreeing with thick-target yields inferred from stacked-foil irradiations by up to an order of magnitude. Based on comparisons of our and prior measurements to Hauser-Feshbach calculations, we estimate the thick-target yield for $^{68}{\rm Ga}$ from $E_α$=14~MeV impinging on 100\%-enriched copper ($^{65}{\rm Cu}$) is 161$^{+5}_{-24}$~MBq/$μ$Ah (for He$^{++}$), which is in agreement with the current IAEA estimate of 156~MBq/$μ$Ah. At $E_α$$=$8~MeV, where radioimpurity-free production of $^{68}{\rm Ga}$ could be realized with a natural copper target, our yield estimate is nearly 4$\times$ lower than the IAEA estimate. We find that the $^{65}{\rm Cu}(α,n)$ cross section estimates presently employed for neutrino and dark matter detector backgrounds and the $^{65}{\rm Cu}(α,n)$ astrophysical reaction rate recently recommended for nucleosynthesis calculations are in agreement with our measurement results.
CommentsAccepted to Applied Radiation and Isotopes
DOI：10.1016/j.apradiso.2026.112956
