"Nuclear isomers are the long-lived excited states of nuclei. Therefore, they constitute the meta-stable landscape of nuclei. The first isomer was probably identified as early as 1921. Since then, the number of isomers has been growing steadily picking up pace in recent times. Interest in nuclear isomers has grown in recent years for many reasons. The experimental capabilities to observe isomers have been expanding to cover a wider time scale. This has opened up new windows to observe and decipher the underlying nuclear structure and interactions. Further, the isomers are beginning to be seen as potential energy storage devices and nuclear clocks with a host of applications. Possible discovery of a gamma ray laser has also ignited many researches in this area. Isomers now cover the full nuclear landscape with structural peculiarities specific to each region of the nuclear chart. Exploring the nuclear isomers, therefore, provides a novel insight into the nuclear structure properties of that region. There could be many different reasons for the long lives of excited nuclear states, which lead to the classification of isomers. Isomers are broadly classified in to four classes: Spin isomers, shape isomers, fission isomers and K-isomers. Seniority isomers have also been identified which are often clubbed with the spin isomers. We discuss this classification and the underlying causes in detail. Many examples are considered to highlight the large variety of isomers. The range of half-lives covered by the isomers varies from billions of years to nano-seconds and even small. To understand this vast variation is a fascinating endeavor in itself. The angular momentum couplings, nuclear shapes, pairing etc. conspire together to give this vast range of half-lives. We go through these aspects in detail, highlighting the various selection rules at work. It is interesting that the nuclear shapes play an important role in many types of isomers. The spin isomers, which occur in spherical or, near-spherical nuclei, are generally confined to the magic numbers. Seniority isomers are largely found in semi-magic nuclei and should be explored in conjunction with the spin isomers. New developments in seniority and generalized seniority isomers are discussed in detail. As the nuclei deform; the nature of isomers changes. We take a close look into the decay properties of isomers in deformed nuclei, particularly the K isomers, the shape isomers and the fission isomers. While doing so, the theoretical and experimental developments of isomers are also addressed. A number of open questions are posed for possible new experiments and better understanding of the isomers."-- Back cover

lgli/P:\springer_dnd140621\springer/10.1007%2F978-3-030-78675-5.pdf

lgrsnf/Nuclear Isomers - A Primer.pdf

scihub/10.1007/978-3-030-78675-5.pdf

zlib/Physics/Nuclear/Ashok Kumar Jain, Bhoomika Maheshwari, Alpana Goel/Nuclear Isomers: A Primer_16696450.pdf

475242_1_En_Print.indd

Jain, Ashok Kumar; Maheshwari, Bhoomika; Goel, Alpana

Ashok Kumar Jain; Bhoomika Maheshwari; Alpana Goel

u6fonter

Springer International Publishing AG

Springer Nature Switzerland AG

Springer Nature, Cham, 2021

Switzerland, Switzerland

Cham, Switzerland, 2021

7, 20210710

lg3051937

producers:
Acrobat Distiller 10.0.0 (Windows)

Foreword 6
Preface 7
Acknowledgements 9
Contents 10
1 An Overview of Nuclear Isomers 13
1.1 Why a Primer on Nuclear Isomers 13
1.2 What are Nuclear Isomers? 13
1.3 Early History 14
1.4 Where are the Isomers Found? 15
1.5 Definition and Scope of Isomers 16
1.6 Half-Life of Isomers 17
1.7 Classification of Isomers and Hindrance Mechanisms 18
1.8 Systematic Features of Isomers 18
1.8.1 Half-Life Systematic 21
1.8.2 Spin Systematic 21
1.8.3 Multipolarity Systematic 23
1.8.4 Role of Pairing in Isomeric Energies 24
References 27
2 Spin Isomers 29
2.1 Isomeric Transitions 29
2.2 Internal Conversion and Isomeric Half-Life 32
2.3 Islands of Spin Isomers Near Magic Numbers 34
2.3.1 g9/2 Spin Isomers 35
2.3.2 h11/2 Spin Isomers 36
2.3.3 i13/2 Spin Isomers 37
2.4 High-Spin Isomers Near the Proton Drip Line 39
2.5 Spin Isomers in 180mTa and the Only Natural Isomer 39
2.6 Spin Isomers in 208Pb 42
2.7 E5 Decaying Spin Isomers 43
References 44
3 Seniority Isomers 46
3.1 Seniority and Seniority Isomers 46
3.1.1 Single-j Quasi-spin Scheme 48
3.1.2 Decay Properties 51
3.1.3 Magnetic Moments and g-Factors 56
3.2 Examples of Seniority Isomers and Their Moments 57
3.2.1 Seniority Isomers in N=50 Isotones 57
3.2.2 Seniority Mixing in 72,74Ni Isotopes 58
3.2.3 Seniority Isomers in 128Pd and 126Pd 60
3.2.4 Seniority Isomers in Pb Isotopes 61
References 61
4 Generalized Seniority Isomers 62
4.1 Multi-j Quasi Spin Scheme 62
4.1.1 Decay Properties 65
4.1.2 Group Theoretical Understanding 67
4.1.3 Excitation Energies 68
4.2 Generalized Seniority in the Sn Isotopes 68
4.2.1 The 10+, 13-, and 15- Isomers 72
4.2.2 Comparison of Sn, Pb and N=82 Isomers 74
4.3 First 2+ and 3- States in Sn, Cd, Te Isotopes 75
4.3.1 Twin Asymmetric B(E2) Parabola in Sn Isotopes 75
4.3.2 Twin Asymmetric B(E2) Parabola in Cd and Te Isotopes 77
4.3.3 Inverted B(E3) Parabola in Sn Isotopes 78
4.3.4 Inverted B(E3) Parabola in Cd and Te Isotopes 79
4.4 Isomeric Moments 81
4.4.1 Quadrupole Moment of 11/2- States 81
4.4.2 Generalized Seniority Schmidt Model 84
References 88
5 K-Isomers in Deformed Nuclei 90
5.1 The K-Quantum Number 90
5.2 Deformed Nilsson Model and High-K States 92
5.2.1 Quasi-particles 94
5.2.2 High-K MQP States and Isomers 95
5.3 Calculation of MQP States 96
5.3.1 Three-Quasiparticle States 99
5.3.2 MQP States 100
5.4 Some General Features of High-K States 101
5.4.1 K-Isomer in 250No 102
5.4.2 K-Mixing 103
5.4.3 K-Isomeric Rotational Band 105
5.5 Theoretical Treatments Used for K-Isomers 105
References 109
6 Shape and Fission Isomers 111
6.1 Double-Hump Barrier and the Shell Corrections 111
6.2 Discovery of the Fission Isomers 114
6.3 Additional Features of Fission Isomers 117
6.4 The Low-Lying 0+ Shape Isomers 118
6.5 Half-Lives of the Shape Isomers 122
6.5.1 Projected Shell Model Calculations 122
6.5.2 Other Microscopic Calculations 123
References 124
7 Unusual Isomers 126
7.1 Examples of Unusual Isomers 126
7.1.1 High Energy Isomers 126
7.1.2 Extremely Low Energy (ELE) Isomers 127
7.1.3 Very High-Spin Isomers 127
7.1.4 Very Long-Lived Isomers 127
7.1.5 Highest Multipolarity Isomers 128
7.1.6 100 % Proton Decaying Isomers 128
7.1.7 Highest Quasi-particle Isomer 128
7.2 ELE Isomers 128
7.3 A Specific Case of ELE Isomer in 229Th 130
7.4 β-Decaying Isomers 134
References 136
8 Experimental Methods, Applications, Future Prospects 139
8.1 Experimental Methods and Applications 139
8.1.1 Gamma Ray Spectroscopy 140
8.1.2 Recoil/Fragment Mass Analyzers 140
8.1.3 Mass Measurement Techniques 141
8.1.4 Highly Charged Ion Storage Rings 142
8.1.5 Isomeric Targets and Isomeric Beams 142
8.1.6 Medical Applications of Isomers 143
8.1.7 Isomer Depletion by External Triggers 144
8.1.8 Moments and g-Factor Measurements 145
8.2 Future Applications of Isomers 147
8.2.1 Isomer Battery and Gamma Ray Laser 147
8.2.2 Nuclear Clock 147
References 148
Appendix Summary 150

2021-07-12