Laser spectroscopy of Radioactive Isotopes

放射性同位素激光光谱

• 批准号: EP/D077133/1
• 负责人: Paul Stevenson
• 金额: $ 11.26万
• 依托单位: University of Surrey
• 依托单位国家: 英国
• 项目类别: Research Grant
• 财政年份: 2007
• 资助国家: 英国
• 起止时间: 2007 至 无数据
• 项目状态: 已结题
• 来源: https://gtr.ukri.org/projects?ref=EP%2FD077133%2F1
• 关键词: Laser; spectroscopy; Radioactive; Isotopes

Nuclear properties such as the size and magnetic field strength slightly shift or perturb the orbits of the atomic electrons.These shifts are small and at the level of a part per million of the electron binding energies. They can be measured with great precision by a variety of techniques using tunable laser light, which can be controlled with part per billion precision. When the laser light is tuned to exactly match an electronic transition frequency, it resonantly excites an isotope of the selected element. The excited atom quickly decays with the emission of fluorescence light which may be detected by photomultipliers sensitive to single photons. In this way the frequency of the laser resonance can be measured experimentally. The analysis of the resonant frequencies across an isotope series allows us to deduce the change in nuclear size as a function of neutron number. It is possible to detect the change of the proton distribution caused by the removal of a single neutron. The same data can show in a clear way whether the nucleus is changing its shape as neutrons are added or subtracted. The magnetic field strength around the nucleus, also measured in these experiments, is produced by the motion of both protons and neutrons. The theory of the magnetic field is well understood and clear conclusions can be drawn about the nucleon orbits occupied by the protons and neutrons. Thus the laser method provides fundamental information on basic properties of the nucleus - size, shape, magnetic properties, nuclear 'spin' angular momentum - which helps to refine our theoretical approaches to explain observed properties, and predict properties of nuclei we can not yet synthesize in the laboratory. The predictive power of these theories is very important. Many of the nuclei unavailable for study on Earth are involved in supernova processes. We cannot begin to understand the processes without first having an understanding of the nuclei involved. The laser techniques we

原子核的性质，如大小和磁场强度，使原子电子的轨道发生轻微的移动或扰动。这些移动很小，只是电子结合能的百万分之一的水平。它们可以通过使用可调激光的各种技术以极高的精度进行测量，这种激光可以以十亿分之一的精度进行控制。当激光被调谐到与电子跃迁频率完全匹配时，它就会共振地激发所选元素的同位素。被激发的原子随着荧光光的发射而迅速衰减，这可能是对单光子敏感的光电倍增管所能探测到的。通过这种方法，可以从实验上测量激光共振的频率。通过对一个同位素系列的共振频率的分析，我们可以推断出原子核大小随中子数的变化。可以检测由于单个中子的去除而引起的质子分布的变化。同样的数据可以清楚地显示原子核是否随着中子的增加或减少而改变其形状。原子核周围的磁场强度也是在这些实验中测量的，是由质子和中子的运动产生的。人们很好地理解了磁场理论，并且可以对质子和中子占据的核子轨道得出明确的结论。因此，激光方法提供了有关原子核的基本性质的基本信息--大小、形状、磁性、核的自旋角动量--这有助于改进我们的理论方法，以解释观察到的性质，并预测我们还不能在实验室合成的原子核的性质。这些理论的预测力非常重要。许多无法在地球上研究的原子核都参与了超新星过程。如果不先了解所涉及的原子核，我们就不能开始了解这些过程。我们的激光技术

项目成果

High-Spin Study of the Shell Model Nucleus 88 Y 49

• DOI: 10.1103/physrevc.87.044337
• 发表时间: 2013-04
• 期刊: Physical Review C
• 影响因子: 3.1
• 作者: M. Bunce;P. Regan;V. Werner;C. Beausang;V. Anagnostatou;M. Bowry;R. Casperson;Danyi Chen;N. Cooper;P. Goddard;R. Hughes;G. Ilie;P. Mason;B. Pauerstein;M. Reed;T. Ross;E. Simpson

Skyrme interaction and nuclear matter constraints

• DOI: 10.1103/physrevc.85.035201
• 发表时间: 2012-03-05
• 期刊: PHYSICAL REVIEW C
• 影响因子: 3.1
• 作者: Dutra, M.;Lourenco, O.;Stevenson, P. D.
• 通讯作者: Stevenson, P. D.

Spectroscopic calculations of the low-lying structure in exotic Os and W isotopes

• DOI: 10.1103/physrevc.83.054303
• 发表时间: 2011-01
• 期刊: Physical Review C
• 影响因子: 3.1
• 作者: K. Nomura;T. Otsuka;R. Rodríguez-Guzmán;L. Robledo;P. Sarriguren;P. Regan;P. Stevenson;Z. Podolyák

Charge radius isotope shift across the N=126 shell gap.

• DOI: 10.1103/physrevlett.110.032503
• 发表时间: 2012-10
• 期刊: Physical review letters
• 影响因子: 8.6
• 作者: P. Goddard;P. Stevenson;Arnau Rios

Lifetime of the yrast I p = 5 - state and E 1 hindrance in the transitional nucleus Ce 58 136

yrast 的寿命 I p = 5 - 状态和 E 1 过渡核 Ce 58 136 中的障碍

• DOI: 10.1103/physrevc.91.027302
• 发表时间: 2015
• 期刊: Physical Review C
• 影响因子: 3.1
• 作者: Alharbi T