RUI: Structure Evolution in the Tellerium Isotopic Chain

RUI：碲同位素链的结构演化

• 批准号: 0139504
• 负责人: Jeffrey Vanhoy
• 金额: $ 6.53万
• 依托单位: United States Naval Academy
• 依托单位国家: 美国
• 项目类别: Interagency Agreement
• 财政年份: 2002
• 资助国家: 美国
• 起止时间: 2002-07-01 至 2005-06-30
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=0139504&HistoricalAwards=false
• 关键词: RUI; Structure; Evolution; Tellerium; Isotopic

Tellurium has a wide range of abundant stable isotopes. The tellurium nuclei have two valence protons with respect to Z = 50 and a range of neutron numbers. Three different types of structure are thought to be active in these nuclei:collective, two-particle, and particle-hole excitations known as intruders. Because there are seven stable even-even Te nuclei, one can study the evolution of these excitation modes over a wide range in neutron number. Emphasis centers on understanding the interplay between particle and collective features and on the aspects of the nuclear forces and shell model orbitals that determine the relative importance. Several models are now able to reproduce the level scheme.Often level energies are more important for evaluating whether a model has sufficient built-in complexity rather than distinguishing between physical descriptions. Transition rate information is crucial to revealing the amplitudes of particle and collective components in the wavefunctions. Excited levels in 130Te below 3.3 MeV will be studied at the University of Kentucky Nuclear Structure Laboratory utilizing inelastic neutron scattering techniques. Electromagnetic transition rates,multipole mixing and branching ratios, and level spins and parities will be deduced from measured gamma-ray excitation functions, coincidences,angular distributions, and Doppler shifts. The excited levels in 118Te and 120Te will be studied at the University of Cologne. The low-spin level scheme will be first verified with gamma-ray spectroscopy following a few-neutron emission reaction. The lifetimes of states in 118Te and 120Te will then be determined using the recoil-distance Doppler shift technique.

柜员具有广泛的稳定同位素。 相对于z = 50和一定范围的中子数具有两个价质子的牙核质子。 在这些核中认为三种不同类型的结构是活性的：集体，两粒子和粒子孔激发被称为入侵者。 因为有七个稳定的均匀te核，所以可以研究这些激发模式在中子数的广泛范围内的演变。 重点是理解粒子和集体特征之间的相互作用以及确定相对重要性的核力量和壳模型轨道的方面。 现在，几种模型能够重现水平方案。通常，水平能量对于评估模型是否具有足够的内置复杂性而不是区分物理描述更为重要。 过渡速率信息对于揭示波形中粒子和集体成分的幅度至关重要。 肯塔基大学核结构实验室将研究130TE以下130TE的激发水平，利用非弹性中子散射技术进行研究。 电磁过渡速率，多极混合和分支比以及水平的自旋和平等将从测得的伽马射线激发功能，巧合，角度分布和多普勒偏移中得出。 118TE和120TE的激动水平将在科隆大学进行研究。 低自旋水平方案将在几个中子发射反应后首先用γ射线光谱验证。然后，将使用后座距离多普勒偏移技术确定118TE和120TE的状态的寿命。