AI 中文总结
研究通过冷中子俘获反应等方法，对$^{92,94,98}$Zr同位素进行研究，确定新能级、γ跃迁及自旋宇称分配，测量中子结合能等，开发新技术估计半衰期，并用壳模型计算解释锆同位素集体性演变。
AI 中文摘要
利用位于格勒诺布尔ILL的EXILL锗阵列，通过冷中子俘获反应研究了$^{92}$Zr的激发态。使用EXILL测量的$^{235}$U中子诱发裂变的高统计量γ符合数据，研究了$^{94}$Zr和$^{98}$Zr核的激发态。目的是寻找$^{92,94,98}$Zr中的新能级并改进对激发态的自旋宇称分配。本工作在这三种同位素中确定了总共54个新能级、180个新γ跃迁和7个新的或改进的自旋宇称分配。确定了$^{92}$Zr中精确的中子结合能为8634.81(2)keV。在$^{94}$Zr中提出了一个Gamow-Teller跃迁。$^{98}$Zr中(9$^-$)、3894.1keV能级可能是一个几纳秒的异构体。本工作开发的一种估计皮秒范围内半衰期的新技术，提供了$^{96,98}$Zr和$^{94,96}$Sr跃迁的61个半衰期和60个B(π,λ)率。由大规模壳模型计算支持的新型系统atics已被用于对50≤N≤60范围内的Zn-Zr偶偶核中的2$^+$激发进行分类。这些信息以及Sr和Zr同位素中0$^+$激发的新系统atics解释了锆同位素中集体性的演变，显示了各种单粒子激发在该区域的相变和共存中的作用。讨论了ν9/2$^+$[404]挤出轨道作为产生0$^+$激发和该区域变形变化的催化剂的作用。
英文摘要
Excited levels in $^{92}$Zr have been studied in cold-neutron capture reaction using the EXILL Ge array at ILL Grenoble. Excited levels in $^{94}$Zr and $^{98}$Zr nuclei have been studied using high-statistics $γ$-coincidence data from neutron-induced fission of $^{235}$U measured with EXILL. The goal of was to search for new levels in $^{92,94,98}$Zr and to improve spin-parity assignments to excited levels. Total of 54 new levels, 180 new $γ$ transitions and 70 new or improved spin-parity assignments have been determined in the three isotopes in the present work. A precise neutron binding energy of 8634.81(2) keV has been determined in $^{92}$Zr. In $^{94}$Zr a Gamow-Teller transition is proposed. The (9$^-$), 3894.1-keV level in $^{98}$Zr is likely a few ns isomer. A new technique of estimating half-lives in a picosecond range, developed in this work, provided 61 half-lives and 60 B($π,λ$) rates for transitions in $^{96,98}$Zr and $^{94,96}$Sr. New-type systematics, backed by Large Scale Shell Model calculations have been used to classify 2$^+$ excitations in Zn-Zr even-even nuclei of the 50$\le$N$\le$60 range. This information and new systematics of 0$^+$ excitations in Sr and Zr isotopes explain the evolution of collectivity in zirconium isotopes, showing the role of various single particle excitations in the phase transition and coexistence of the region. The role of the $ν$9/2$^+$[404] extruder orbital as a catalyst in creating 0$^+$ excitations and the deformation change in the region has been discussed.
Comments30 pages, 20 figures
