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/L005808/1
• 负责人: John Smith
• 金额: $ 48.39万
• 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: 2014
• 资助国家: 英国
• 起止时间: 2014 至 无数据
• 项目状态: 已结题
• 来源: https://gtr.ukri.org/projects?ref=ST%2FL005808%2F1
• 关键词: University; West; Scotland; Nuclear; Physics

It is just over 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 ongoing 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. The overarching aim 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, and for heavy nuclei. Recent experimental observations, supported by theoretical calculations, have begun to suggest that the structure of exotic nuclei may be different from nuclei 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. In order to provide a test of nuclear models, experimental data are needed. In this respect, we will primarily focus our research on two areas of the nuclear chart, close to two doubly-magic nuclei: the proton-rich nuclei around Sn100 (N=Z=50) and the neutron-rich nuclei close to Sn132 (Z=50, N=82). An important consideration in the description of an atomic nucleus is its shape. It is well established that nuclei with filled shells of neutrons and protons are spherical, and nuclei with partially-filled shells can become deformed. Indeed, it is the deformation of the nucleus into a prolate (rugby ball) shape, that leads to rotational excitations. A more exotic form of deformation is when the nucleus takes on a reflection-asymmetric "pear shape". The so-called "octupole deformation" is most prominent in localized regions of the nuclear chart, such as the light actinide region (radium, thorium, uranium nuclei with A~224) and the neutron-rich lanthanides (such as the A~144 barium and cerium nuclei). Although octupole correlations in nuclei have been studied for a number of years, recent developments in accelerator and detector technology will now allow experiments to be performed to provide new insights into this type of deformation. In our research programme, we will make a comprehensive study of octupole correlations in nuclei, focusing on the actinide and lanthanide regions, as well as the proton-rich nuclei near N=Z=56. The mirror-symmetry-violating pear shape allows for the search for physics that is responsible for the existent matter-antimatter symmetry violation. Our research will primarily proceed using different methods of gamma-ray spectroscopy. We will use the best facilities available for the physics goals of the project. For example, we will carry out Coulomb excitation experiments at ISOLDE at CERN, fission-fragment spectroscopy at Institut Laue Langevin in Grenoble, and gamma-ray plus conversion electron spectroscopy with SAGE at JYFL in Jyväskylä, Finland. The funds requested here will provide support for postdoctoral research associates and PhD Students to help carry out this work, as well as funds for travel and subsistence. We have also requested funds to enable world leading theoretical nuclear physicists to visit our group to help with the interpretation of our results, and to provide important theoretical input into our experimental research programme.

距欧内斯特·卢瑟福（Ernest Rutherford）证明原子核存在的开创性实验刚刚过去100多年。在随后的一个世纪里，具有里程碑意义的发展，如20世纪40年代核壳模型的开始，20世纪60年代重离子加速器的建设，以及核探测器技术的重大进展，已经牢固地确立了核物理学作为科学研究前沿的国际活动。在过去的几十年里，对远离稳定谷的奇异核的性质的探索已经取得了相当大的实验进展。本综合拨款申请所述的研究计划涵盖对远离稳定的原子核的结构和性质的研究。我们研究计划的首要目标是更好地理解外来核的结构和行为，包括稳定谷中富含中子和质子的那一边，以及重核。在理论计算的支持下，最近的实验观察已经开始表明，外来核的结构可能与接近稳定的核不同。例如，众所周知的魔数序列，对应于核壳结构中的能量间隙，现在被认为在原子核中随着中子的极端过剩而发生变化。在中子数N=20附近，这种变化的证据已经令人信服，并且在N=28、50和82的其他壳隙中，预计也会产生类似的影响。为了提供核模型的测试，需要实验数据。在这方面，我们将主要集中研究原子核图的两个区域，靠近两个双魔核：Sn100附近的富质子核（N=Z=50）和Sn132附近的富中子核（Z=50， N=82）。描述原子核时要考虑的一个重要问题是它的形状。众所周知，壳层被中子和质子填充的原子核是球形的，而壳层被部分填充的原子核则会变形。事实上，正是原子核变形成一个长形（橄榄球）的形状，导致了旋转激发。一种更奇特的变形形式是原子核呈现出反射不对称的“梨形”。所谓的“八极变形”在核图的局部区域最为突出，如轻锕系元素区（镭、钍、含A~224的铀核）和富中子镧系元素区（如A~144的钡和铈核）。尽管人们已经研究了原子核中的八极相关数年，但加速器和探测器技术的最新发展现在将允许进行实验，为这种变形提供新的见解。在我们的研究计划中，我们将对原子核中的八极相关进行全面的研究，重点是锕系和镧系区域，以及N=Z=56附近的富质子核。违反镜像对称的梨形允许寻找导致存在的物质-反物质对称违反的物理。我们的研究将主要使用不同的伽马射线光谱学方法。我们将使用最好的设备来实现这个项目的物理目标。例如，我们将在CERN的ISOLDE进行库仑激发实验，在格勒诺布尔的Laue Langevin研究所进行裂变碎片光谱，在芬兰Jyväskylä的JYFL与SAGE进行伽马射线加转换电子能谱。申请的资金将用于支持博士后研究员和博士生开展这项工作，以及旅费和生活费。我们还要求提供资金，使世界领先的理论核物理学家能够访问我们的小组，帮助解释我们的结果，并为我们的实验研究计划提供重要的理论投入。

项目成果

Studies of Re?ection Asymmetry in Heavy Nuclei

重核反射不对称性的研究

• DOI: 10.1088/1402-4896/ad22c9
• 发表时间: 2024
• 期刊: Physica Scripta
• 影响因子: 2.9
• 作者: Butler P

Experimental study of the lifetime and phase transition in neutron-rich Zr 98 , 100 , 102

富中子Zr 98 , 100 , 102 寿命和相变的实验研究

• DOI: 10.1103/physrevc.96.054323
• 发表时间: 2017
• 期刊: Physical Review C
• 影响因子: 3.1
• 作者: Ansari S

Near-yrast excitations in nucleus As 83 : Tracing the p g 9 / 2 orbital in the Ni 78 region

As 83 核中的近 yrast 激发：追踪 Ni 78 区域中的 p g 9 / 2 轨道

• DOI: 10.1103/physrevc.91.047302
• 发表时间: 2015
• 期刊: Physical Review C
• 影响因子: 3.1
• 作者: Baczyk P

Evolution of Octupole Deformation in Radium Nuclei from Coulomb Excitation of Radioactive ^{222}Ra and ^{228}Ra Beams.

• DOI: 10.1103/physrevlett.124.042503
• 发表时间: 2020-01
• 期刊: Physical review letters
• 影响因子: 8.6
• 作者: P. Butler;L. Gaffney;P. Spagnoletti;K. Abrahams;M. Bowry;J. Cederkäll;G. de Angelis;H. De Witte;P. Garrett;A. Goldkuhle;C. Henrich;A. Illana;K. Johnston;D. Joss;J. Keatings;N. Kelly;M. Komorowska;J. Konki;T. Kröll;M. Lozano;B. S. Nara Singh;D. O’Donnell;J. Ojala;R. Page;L. Pedersen;C. Raison;P. Reiter;Julia Bella Rodriguez;D. Rosiak;S. Rothe;M. Scheck;M. Seidlitz;T. Shneidman;B. Siebeck;J. Sinclair;J. F. Smith-J. F.-Smith-2127105908;M. Stryjczyk;P. Van Duppen;S. Viñals;V. Virtanen;N. Warr;K. Wrzosek-Lipska;M. Zielińska

Lifetime measurement in neutron-rich A~100 nuclei

富中子 A~100 原子核的寿命测量

• DOI: 10.1051/epjconf/201819305003
• 发表时间: 2018
• 期刊: EPJ Web of Conferences
• 作者: Ansari S