Nuclear Structure and Reactions: Theory and Experiment
Lead Research Organisation:
University of Surrey
Department Name: Physics
Abstract
Nuclear physics research is undergoing a transformation. For a hundred years, atomic nuclei have been probed by collisions between stable beams and stable targets, with just a small number of radioactive isotopes being available. Now, building on steady progress over the past 20 years, it is at last becoming possible to generate intense beams of a wide range of short-lived isotopes, so-called 'radioactive beams'. This enables us vastly to expand the scope of experimental nuclear research. For example, it is now realistic to plan to study in the laboratory a range of nuclear reactions that take place in exploding stars. Thereby, we will be able to understand how the chemical elements that we find on Earth were formed and distributed through the Universe. At the core of our experimental research is our strong participation at leading European radioactive-beam facilities: FAIR at GSI, Darmstadt, Germany; SPIRAL at GANIL, Caen, France; and ISOLDE at CERN, Geneva, Switzerland. While we are now contributing, or planning to contribute, to substantial technical developments at these facilities, the present grant request is focused on the exploitation of the capabilities that are now becoming available. To achieve our physics objectives, we also need to use other facilities, including stable-isotope accelerators, since these can provide complementary capabilities. Experimental progress is intimately linked with theory, where novel and practical approaches are a hallmark of the Surrey group. A key and unique feature (within the UK) of our group is our blend of theoretical and experimental capability. Our science goals are aligned with current STFC strategy for nuclear physics, as expressed in detail through the Nuclear Physics Advisory Panel. We wish to understand the boundaries of nuclear existence, i.e. the limiting conditions that enable neutrons and protons to bind together to form nuclei. Under such conditions, the nuclear system is in a delicate state and shows unusual phenomena. It is very sensitive to the properties of the nuclear force. For example, weakly bound neutrons can orbit their parent nucleus at remarkably large distances. This is already known, and our group made key contributions to this knowledge. What is unknown is whether, and to what extent, the neutrons and protons can show different collective behaviours. Also unknown, for most elements, is how many neutrons can bind to a given number of protons. It is features such as these that determine how stars explode. So, we need a more sophisticated understanding of the nuclear force, and we need experimental information about nuclei with unusual combinations of neutrons and protons to test our theoretical ideas and models. Therefore, theory and experiment go hand-in-hand as we push forward towards the nuclear limits. An overview of nuclear binding reveals that about one half of predicted nuclei have never been observed, and the vast majority of this unknown territory involves nuclei with an excess of neutrons. The focus of our activity addresses this 'neutron-rich' territory, exploiting the new capabilities with radioactive beams. Our principal motivation is the basic science, and we contribute strongly to the world sum of knowledge and understanding. Nevertheless, there are more-tangible benefits. For example, our radiation-detector advances can be incorporated in medical diagnosis and treatment. In addition, we provide an excellent training environment for our research students and staff, many of whom go on to work in the nuclear power industry, helping to fill the current skills gap. On a more adventurous note, our special interest in nuclear isomers (energy traps) could lead to novel energy applications. Furthermore, we have a keen interest in sharing our specialist knowledge with a wide audience, and we already have an enviable track record with the media.
Organisations
Publications
Sumikama T
(2021)
Observation of new neutron-rich isotopes in the vicinity of Zr 110
in Physical Review C
McDaniel S
(2012)
Intermediate-energy inverse-kinematics one-proton pickup reactions on neutron-deficient f p -shell nuclei
in Physical Review C
Colomer F
(2016)
Extension of the ratio method to low energy
in Physical Review C
Somà V
(2013)
Ab initio Gorkov-Green's function calculations of open-shell nuclei
in Physical Review C
McCleskey E
(2016)
Simultaneous measurement of ß -delayed proton and ? decay of P 27
in Physical Review C
Kobayashi N
(2016)
One-neutron removal from Ne 29 : Defining the lower limits of the island of inversion
in Physical Review C
Pang D
(2013)
Rapid convergence of the Weinberg expansion of the deuteron stripping amplitude
in Physical Review C
Söderström P
(2012)
High-spin structure in 40 K
in Physical Review C
Carbone A
(2014)
Correlated density-dependent chiral forces for infinite-matter calculations within the Green's function approach
in Physical Review C
Cipollone A
(2015)
Chiral three-nucleon forces and the evolution of correlations along the oxygen isotopic chain
in Physical Review C
Baldwin T
(2012)
First excited 1 2 + state in 9 B
in Physical Review C
Liu H
(2012)
Understanding the different rotational behaviors of 252 No and 254 No
in Physical Review C
Reed M
(2012)
Long-lived isomers in neutron-rich Z = 72 -76 nuclides
in Physical Review C
Grinyer G
(2012)
Systematic study of p -shell nuclei via single-nucleon knockout reactions
in Physical Review C
Jiao C
(2015)
Shape-coexisting rotation in neutron-deficient Hg and Pb nuclei
in Physical Review C
Timofeyuk N
(2012)
Core excitations and narrow states beyond the proton dripline: The exotic nucleus 21 Al
in Physical Review C
Taprogge J
(2015)
ß decay of Cd 129 and excited states in In 129
in Physical Review C
Tostevin J
(2013)
Two-proton removal from 44 S and the structure of 42 Si
in Physical Review C
Caesar C
(2013)
Beyond the neutron drip line: The unbound oxygen isotopes 25 O and 26 O
in Physical Review C
Carbone A
(2013)
Symmetric nuclear matter with chiral three-nucleon forces in the self-consistent Green's functions approach
in Physical Review C
Morrison L
(2020)
Quadrupole deformation of Xe 130 measured in a Coulomb-excitation experiment
in Physical Review C
Grahn T
(2016)
Excited states and reduced transition probabilities in Os 168
in Physical Review C
Chen F
(2012)
Residual interactions and the K -mixing-induced fast decay of the three-quasiparticle isomer in 171 Tm
in Physical Review C
Nita C
(2014)
Fast-timing lifetime measurements of excited states in Cu 67
in Physical Review C
Lorusso G
(2015)
ß-Decay Half-Lives of 110 Neutron-Rich Nuclei across the N=82 Shell Gap: Implications for the Mechanism and Universality of the Astrophysical r Process.
in Physical review letters
Gottardo A
(2012)
New isomers in the full seniority scheme of neutron-rich lead isotopes: the role of effective three-body forces.
in Physical review letters
Kobayashi N
(2014)
Observation of a p-wave one-neutron halo configuration in (37)Mg.
in Physical review letters
Watanabe H
(2013)
Isomers in 128Pd and 126Pd: evidence for a robust shell closure at the neutron magic number 82 in exotic palladium isotopes.
in Physical review letters
Guastalla G
(2013)
Coulomb excitation of 104Sn and the strength of the 100Sn shell closure.
in Physical review letters
Atar L
(2018)
Quasifree (p, 2p) Reactions on Oxygen Isotopes: Observation of Isospin Independence of the Reduced Single-Particle Strength.
in Physical review letters
Kolos K
(2016)
Direct Lifetime Measurements of the Excited States in (72)Ni.
in Physical review letters
Cipollone A
(2013)
Isotopic chains around oxygen from evolved chiral two- and three-nucleon interactions.
in Physical review letters
Leistenschneider E
(2018)
Dawning of the N=32 Shell Closure Seen through Precision Mass Measurements of Neutron-Rich Titanium Isotopes.
in Physical review letters
Morales AI
(2014)
Half-life systematics across the N=126 shell closure: role of first-forbidden transitions in the ß decay of heavy neutron-rich nuclei.
in Physical review letters
Flavigny F
(2013)
Limited asymmetry dependence of correlations from single nucleon transfer.
in Physical review letters
Scott M
(2017)
Observation of the Isovector Giant Monopole Resonance via the Si 28 ( Be 10 , B * 10 [ 1.74 MeV ] ) Reaction at 100 A MeV
in Physical Review Letters
Tain JL
(2015)
Enhanced ?-Ray Emission from Neutron Unbound States Populated in ß Decay.
in Physical review letters
Taprogge J
(2014)
1 p 3 / 2 Proton-Hole State in Sn 132 and the Shell Structure Along N = 82
in Physical Review Letters
Nakamura T
(2014)
Deformation-driven p-wave halos at the drip line: 31Ne.
in Physical review letters
Pain SD
(2015)
Constraint of the astrophysical ^{26g}Al(p,?)^{27}Si destruction rate at stellar temperatures.
in Physical review letters
Revel A
(2020)
Extending the Southern Shore of the Island of Inversion to F 28
in Physical Review Letters
Bailey GW
(2016)
Sensitivity of (d, p) Reactions to High n-p Momenta and the Consequences for Nuclear Spectroscopy Studies.
in Physical review letters
Gade A
(2014)
Nuclear structure towards N = 40 60Ca: in-beam ?-ray spectroscopy of 58,60Ti.
in Physical review letters
Zakari-Issoufou AA
(2015)
Total Absorption Spectroscopy Study of (92)Rb Decay: A Major Contributor to Reactor Antineutrino Spectrum Shape.
in Physical review letters
Davies PJ
(2013)
Mirror energy differences at large isospin studied through direct two-nucleon knockout.
in Physical review letters
Chen L
(2013)
Direct observation of long-lived isomers in 212Bi.
in Physical review letters
Milne SA
(2016)
Isospin Symmetry at High Spin Studied via Nucleon Knockout from Isomeric States.
in Physical review letters
Orrigo SE
(2014)
Observation of the ß-delayed ?-proton decay of (56)Zn and its impact on the Gamow-Teller strength evaluation.
in Physical review letters
Rosenbusch M
(2015)
Probing the N=32 Shell Closure below the Magic Proton Number Z=20: Mass Measurements of the Exotic Isotopes ^{52,53}K.
in Physical review letters
Wimmer K
(2012)
Correlations in intermediate energy two-proton removal reactions.
in Physical review letters
Description | We have advanced the following areas: understanding the limits of the nuclear landscape, especially the neutron-rich limits; understanding and exploiting the reactions needed to reach the limits; studying and understanding novel structures observed on approaching the limits; engaging fully with the international community of nuclear physicists; disseminating results through leading journals and conferences; providing excellent training. |
Exploitation Route | The main beneficiaries of this work will be the national and international nuclear physics communities. In addition, the expected results on shell structure and isomeric states will also be of significant interest to the nuclear-astrophysics and isomer-application communities. We have an active involvement and information exchange with both these nuclear structure 'user' communities. The isomer work also links closely to the atomic physics community, in particular through the study of highly charged ions stored in rings and traps. Our theoretical methods will be of interest to the condensed-matter community, especially in relation to pairing condensates. The work on detector development has wide potential applications for medical diagnosis and treatment. The research will also provide manpower trained to a high level (PhDs and PDRAs with a deep understanding of radiation physics and sensor technologies) who may subsequently be employed in many different areas, such as national security, the nuclear power industries, environmental monitoring and control, and medical physics. |
Sectors | Education,Energy,Environment,Healthcare,Security and Diplomacy |
Description | No specific non-academic impact has yet become material. |