Abstract The 92-keV resonance in the 25Mg ( p , γ ) 26 Al reaction plays a key role in the production of 26Al at astrophysical burning temperatures of ≈100 MK in the Mg-Al cycle. However, the state can decay to feed either the ground, 26 g Al, or isomeric state, 26 m Al. It is the ground state that is critical as the source of cosmic γ rays. It is therefore important to precisely determine the ground-state branching fraction f 0 of this resonance. Here we report on the identification of four γ-ray transitions from the 92-keV resonance, and determine the spin of the state and its ground-state branching fraction f 0 = 0.52 ( 2 ) s t a t ( 6 ) s y s t . The f 0 value is the most precise reported to date, and at the lower end of the range of previously adopted values, implying a lower production rate of 26 g Al and its cosmic 1809-keV γ rays.

中文翻译：

---

25Mg(p,γ)对宇宙γ射线发射体26Al的基态和异构态的反应中关键的92-keV共振衰减

摘要 25Mg ( p , γ ) 26 Al 反应中的 92-keV 共振在 Mg-Al 循环中 ≈100 MK 的天体物理燃烧温度下生产 26Al 起着关键作用。但是，该状态可以衰变以供给地面 26 g Al 或异构状态 26 m Al。它是作为宇宙γ射线源至关重要的基态。因此，精确确定该共振的基态分支分数 f 0 很重要。在这里，我们报告了从 92 keV 共振中识别出四个 γ 射线跃迁，并确定了状态的自旋及其基态分支分数 f 0 = 0.52 (2) stat (6) 系统。f 0 值是迄今为止报道的最精确的值，并且处于先前采用的值范围的下端，这意味着 26 g Al 及其宇宙 1809-keV γ 射线的生产​​率较低。