University of the West of Scotland Nuclear Physics Group Consolidated Grant

西苏格兰大学核物理组综合拨款

• 批准号: ST/J000183/2
• 负责人: John Smith
• 金额: $ 12.96万
• 依托单位: University of the West of Scotland
• 依托单位国家: 英国
• 项目类别: Research Grant
• 财政年份: 2012
• 资助国家: 英国
• 起止时间: 2012 至 无数据
• 项目状态: 已结题
• 来源: https://gtr.ukri.org/projects?ref=ST%2FJ000183%2F2
• 关键词: University; West; Scotland; Nuclear; Physics

It is almost exactly 100 years since Ernest Rutherford's pioneering experiments which demonstrated the existence of the atomic nucleus. In the century that has followed, landmark developments, such as the inception of the nuclear shell model in the 1940s, the construction of heavy-ion accelerators in the 1960s, and major advances in nuclear-detector techniques, have firmly established nuclear physics as an international activity at the forefront of scientific research. In the past few decades, the quest to understand the properties of exotic nuclei ever further from the valley of stability has led to considerable experimental progress. The programme of research described in this Consolidated Grant application covers research into the structure and properties of atomic nuclei that lie far from stability. One of the main aims of our research programme is to achieve a better understanding of the structure and behaviour of exotic nuclei on both the neutron-rich and proton-rich sides of the valley of stability. Recent experimental observations, supported by theoretical calculations, have begun to suggest that the structure of neutron-rich nuclei may be different from those near stability. For example, the well known sequence of magic numbers, corresponding to energy gaps in nuclear shell structure, is now thought to change in nuclei with an extreme excess of neutrons. The evidence for such a change is already convincing around neutron number N=20, and similar effects are expected for the other shell gaps at N=28, 50, and 82. We will study the evolution of shell gaps in neutron-rich nuclei using both gamma-ray and charged-particle spectroscopy techniques. Above mass number A~100, electrostatic repulsion causes stable nuclei to have more neutrons than protons. Proton-rich nuclei just above the doubly-magic Sn100 nucleus are those with near equal numbers of neutrons and protons. These nuclei are known to decay by exotic decay modes such as proton emission. Spectroscopic study of the properties of these decays can give invaluable information about the properties of the nucleus in its ground state and in the first few excited states. Our research programme will include studies of proton-rich nuclei around A~110 by investigating their particle decays and by gamma-ray spectroscopy. Another aspect of our research programme will be devoted to studying fission of the nucleus. Fission is a collective mode of decay most commonly associated with heavy nuclei in the uranium region, but in our research we will study the beta-delayed fission of exotic nuclei in the lead region that lie very far from stability (by ~20-25 neutrons) and which have only recently become experimentally accessible with the development of radioactive beams. A study of the properties of beta-delayed fission, such as the mass distributions of the fission fragments, will give important information about nuclear structure and shell effects at low excitation energy. In a related part of our research programme, we will use radioactive At beams to study other nuclear-structure effects such as shape coexistence. Our research programme has several themes which will use different methodologies. Primarily, our experiments will be carried out using state-of-the-art apparatus at large international facilities. Gamma-ray spectroscopy offers one of the best methods of studying the structure of exotic nuclei, and here we will exploit the new AGATA gamma-ray tracking spectrometer at Legnaro National Laboratory, GSI and GANIL. Another part of our research will make use of the Jurogam gamma-ray spectrometer with the RITU recoil separator at Jyväskylä in Finland. Our programme to study beta-delayed fission will make use of beams of radioactive isotopes from the ISOLDE facility at CERN and at the JAEA laboratory in Japan. Furthermore, we will exploit the development of new radioactive beams of astatine at ISOLDE.

距离欧内斯特·卢瑟福 (Ernest Rutherford) 证明原子核存在的开创性实验已经过去了几乎整整 100 年。在接下来的一个世纪中，出现了里程碑式的发展，例如 20 世纪 40 年代核壳模型的诞生、重离子加速器的建造。 20 世纪 60 年代，核探测器技术的重大进步，使核物理学牢固地确立为处于科学研究前沿的国际活动。远离稳定谷的奇异核的研究已经取得了相当大的实验进展，该综合拨款申请中描述的研究计划涵盖了远离稳定的原子核的结构和性质的研究。研究计划是为了更好地了解稳定谷富中子和富质子两侧的奇异核的结构和行为，最近的实验观察在理论计算的支持下已经开始表明，富中子核可能与那些不同例如，众所周知的幻数序列，对应于核壳层结构中的能隙，现在被认为会在中子数量极度过剩的情况下发生变化，这种变化的证据已经在中子数 N 周围令人信服。 =20，预计 N=28、50 和 82 时的其他壳层间隙也会产生类似的效果。我们将使用伽马射线和高于质量的带电粒子光谱技术研究富中子核中壳层间隙的演化。数字A~100，静电斥力导致稳定的原子核比双幻 Sn100 原子核上方的富含质子的原子核具有几乎相同数量的中子和质子，已知这些原子核会通过奇异的衰变模式进行衰变。对这些衰变特性的光谱研究可以提供有关原子核在基态和最初几个激发态的特性的宝贵信息。我们研究计划的另一个方面将致力于研究原子核裂变，这是一种与重原子核最常见的集体衰变模式。铀区域，但在我们的研究中，我们将研究前导区域中外来核的 β 延迟裂变，这些核离稳定很远（大约 20-25 个中子），并且最近才开始进行实验随着放射性束的发展，对β延迟裂变特性的研究，例如裂变碎片的质量分布，将在我们的相关部分提供有关低激发能量下的核结构和壳层效应的重要信息。在研究计划中，我们将使用放射性原子束来研究其他核结构效应，例如形状共存。我们的研究计划有几个主题，将使用不同的方法，主要是使用最先进的设备进行实验。伽马射线光谱仪是研究奇异核结构的最佳方法之一，在这里我们将利用莱尼亚罗国家实验室、GSI 和 GANIL 的新型 AGATA 伽马射线跟踪光谱仪进行研究。我们将在芬兰于韦斯屈莱 (Jyväskylä) 使用配备 RITU 反冲分离器的 Jurogam 伽马射线能谱仪。此外，我们还将在 ISOLDE 开发新的砹放射性束。

项目成果

First in-beam ? -ray study of the level structure of neutron-rich S 39

第一个光束内？

• DOI: http://dx.10.1103/physrevc.94.024325
• 发表时间: 2016
• 期刊: Physical Review C
• 影响因子: 3.1
• 作者: Chapman R

Direct Evidence of Octupole Deformation in Neutron-Rich ^{144}Ba.

富中子中八极变形的直接证据^{144}Ba。

• DOI: http://dx.10.1103/physrevlett.116.112503
• 发表时间: 2016
• 期刊: Physical review letters
• 影响因子: 8.6
• 作者: Bucher B

Electromagnetic Transition Rate Measurements in the N =80 Isotone, 138 Ce

N =80 Isotone、138 Ce 中的电磁跃迁率测量

• DOI: http://dx.10.1088/1742-6596/381/1/012057
• 发表时间: 2012
• 期刊: Conference Series
• 作者: Alharbi T

Delayed or absent p ( h 11 / 2 ) 2 alignment in Xe 111

Xe 111 中的 p ( h 11 / 2 ) 2 对齐延迟或缺失

• DOI: http://dx.10.1103/physrevc.101.014313
• 发表时间: 2020
• 期刊: Physical Review C
• 影响因子: 3.1
• 作者: Capponi L

Shape coexistence in the neutron-deficient even-even (182-188)Hg isotopes studied via coulomb excitation.

通过库仑激发研究了缺中子偶-偶 (182-188)Hg 同位素的形状共存。

• DOI: http://dx.10.1103/physrevlett.112.162701
• 发表时间: 2014
• 期刊: Physical review letters
• 影响因子: 8.6
• 作者: Bree N