论文标题
热激发核的α衰变
Alpha decay of thermally excited nuclei
论文作者
论文摘要
$ 10^9 $ K的温度下，在天体物理环境中产生的重型核的突出衰减模式之一是$α$（$^4 $ HE）衰减。在隧道衰减的标准方案中评估了热增强的$α$衰减率，在该标准方案中，通过与子核的相互作用形成的$α$粒子隧道。遵循观察到的几个兴奋的水平，当女儿核处于外壳闭合时可能会衰减$α$，我们尤其专注于产生具有中子数的女儿核的衰变，n = 126。在一种统计方法中，我们发现半衰期$ t_ {1/2}（t）$ a $ t $ t $ t $ t of 2.4 gk.4 $^{212} $ po的衰减除外，它衰减给双重魔术女儿$^{208} $ pb，其中$ t_ {1/2}（t）$减少了5个级级。鉴于质量增强的质量在等待点的核构建具有封闭的中子壳，这些热增强的$α$衰变对$ r $ $ process的核合成的影响可能很重要。
One of the prominent decay modes of heavy nuclei which are produced in astrophysical environments at temperatures of the order of $10^9$ K is the $α$ ($^4$He) decay. Thermally enhanced $α$ decay rates are evaluated within the standard scheme of a tunneling decay where the $α$ particle tunnels through the potential barrier formed by its interaction with the daughter nucleus. Following the observation that there exist several excited levels with the possibility of an $α$ decay when the daughter nucleus is at a shell closure, we focus in particular on decays producing daughter nuclei with the neutron number, N = 126. Within a statistical approach we find that the half-lives, $t_{1/2}(T)$, for temperatures ranging from $T$ = 0 to 2.4 GK can decrease by 1 - 2 orders of magnitude with the exception of the decay of $^{212}$Po which decays to the doubly magic daughter $^{208}$Pb, where $t_{1/2}(T)$ decreases by 5 orders of magnitude. The effect of these thermally enhanced $α$ decays on the $r$-process nucleosynthesis can be significant in view of the mass build up at the waiting point nuclei with closed neutron shells.
