AI 中文总结
本研究探究了介于α衰变与裂变间的集团发射性质，确定了最可能的母核-集团对，计算了相关衰变率并分析其对中子星并合中r过程核合成的影响，发现现有集团发射衰变率不影响r过程核合成结果。
AI 中文摘要
集团发射是介于α衰变和裂变之间的一种奇特衰变模式，母核发射出比α粒子重、但通常被视为裂变碎片的粒子轻的核子集团。本研究通过分析ISOLDE（欧洲核子研究中心）产生的质量数A=230的束流谱中探测到的5个高能事件，对集团发射的性质进行了研究。在假设这些事件由集团发射引起的前提下，确定了导致这5个高能事件的最可能母核-集团对为²³⁰Ra发射²²O，其分支比为(4.3±1.9)×10⁻⁹。研究采用4个解析公式估算了一组富中子核的集团发射部分半衰期，对每种母同位素选定的集团核计算了衰变率，并将每个母核的所有集团发射衰变通道的率纳入中子星并合中r过程核合成的计算，以探究集团发射对r过程核素生成的可能影响。将得到的同位素丰度分布与未考虑集团发射的情况进行了比较，结果表明，采用现有简单解析公式纳入的集团发射衰变率不会影响r过程核合成的结果。
英文摘要
Cluster emission is an exotic decay mode between alpha-decay and fission, in which a parent nucleus emits a cluster of nucleons heavier than an alpha-particle, but lighter than what is usually considered a fission fragment. The properties of cluster emission were investigated by analyzing five high-energy events detected in a spectrum of a mass A = 230 beam produced at ISOLDE (CERN). Under the assumption that these events were caused by cluster emission, the most likely parent-cluster pair responsible for the five high-energy events, was found to be $^{230}Ra$ emitting $^{22}O$, with a branching ratio of $(4.3$ +\- $1.9) \times 10^{-9}$. Four analytical formulas were used to estimate the partial half-lives of cluster emission for a group of neutron-rich nuclei. The decay rate was calculated for a selection of cluster nuclei for each parent isotope. The rates of all decay channels of cluster emission per parent nucleus were then included in calculations of the r-process nucleosynthesis in a neutron star merger in order to study the possible impact of cluster emission on the r-process nuclear production. The resulting isotopic abundance distributions were compared to those calculated for a case in which cluster emission was not considered. It was found that the inclusion of cluster emission decay rates from the simple analytical formulas available nowadays does not influence the results of the r-process nucleosynthesis.
Comments21 pages, 5 figures
