论文标题
$^{25} $ si $β^+$ - 衰减光谱
$^{25}$Si $β^+$-decay spectroscopy
论文作者
论文摘要
$β$ -DECAY光谱学提供了有关外来核的有价值信息，并对稳定性线之外的核理论进行了严格的测试。搜索新的$β$删除质子和$^{25} $ si的$γ$射线，以调查$^{25} $ al兴奋状态的属性。 $^{25} $ si $β$衰减是通过在国家超导回旋体实验室与锗标记系统的气态检测器一起测量的。同时检测到衰减中发出的质子和$γ$射线。使用一种蒙特卡洛方法来建模$^{24} $ mg $γ$ ray线的多普勒拓宽是由质子排放引起的核后坐力引起的。使用两个新开发的通用\ textit {sd} -shell Hamiltonians，USDC和USDI计算。迄今已确定了最精确的$^{25} $ SI半衰期。已经确定了一个新的质子分支，位于724（4）〜keV和新的质子 - $γ$ -Ray的巧合。三个$^{24} $ mg $γ$ - ray线和八个$^{25} $ al $γ$ - ray线首次在$^{25} $ si衰减中观察到。报告了$^{25} $ si $β$ delayed $γ$ ray强度通过$^{25} $ al unbound态的第一个测量。观察到$^{25} $ al的所有绑定状态都在$^{25} $ si的$β$衰减中填充。已经解决了以前的测量之间的几个不一致之处，并提供了有关$^{25} $ al级方案的新信息。已经构建了增强的衰减方案，并将其与$^{25} $ na的镜像衰减和Shell-Model计算进行了比较。测得的激发能，$γ$ - 雷和质子分支，log〜 $ ft $值以及$^{25} $ al填充的状态的gamow-teller过渡强度，$^{25} $ si与Shell-Model的计算非常吻合，在$^{25} $ si中均具有良好的一致性，可以很好地达成一致的n $ n $ n $ n $ n $^$^$^$^$^$^$^25 {
$β$-decay spectroscopy provides valuable information on exotic nuclei and a stringent test for nuclear theories beyond the stability line. To search for new $β$-delayed protons and $γ$ rays of $^{25}$Si to investigate the properties of $^{25}$Al excited states. $^{25}$Si $β$ decays were measured by using the Gaseous Detector with Germanium Tagging system at the National Superconducting Cyclotron Laboratory. The protons and $γ$ rays emitted in the decay were detected simultaneously. A Monte Carlo method was used to model the Doppler broadening of $^{24}$Mg $γ$-ray lines caused by nuclear recoil from proton emission. Shell-model calculations using two newly developed universal \textit{sd}-shell Hamiltonians, USDC and USDI, were performed. The most precise $^{25}$Si half-life to date has been determined. A new proton branch at 724(4)~keV and new proton-$γ$-ray coincidences have been identified. Three $^{24}$Mg $γ$-ray lines and eight $^{25}$Al $γ$-ray lines are observed for the first time in $^{25}$Si decay. The first measurement of the $^{25}$Si $β$-delayed $γ$ ray intensities through the $^{25}$Al unbound states is reported. All the bound states of $^{25}$Al are observed to be populated in the $β$ decay of $^{25}$Si. Several inconsistencies between the previous measurements have been resolved, and new information on the $^{25}$Al level scheme is provided. An enhanced decay scheme has been constructed and compared to the mirror decay of $^{25}$Na and the shell-model calculations. The measured excitation energies, $γ$-ray and proton branchings, log~$ft$ values, and Gamow-Teller transition strengths for the states of $^{25}$Al populated in the $β$ decay of $^{25}$Si are in good agreement with the shell-model calculations, offering gratifyingly consistent insights into the fine nuclear structure of $^{25}$Al.
