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 international radioactive-beam facilities. 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.
Experimental progress is intimately linked with theory, where novel and practical approaches are a hallmark of the Surrey group. An outstanding feature, which is key to our group's research plans and is unique in the UK, is our powerful 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. To tackle these problems, 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. Much 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.
At the core of our experimental research is our strong participation at leading international radioactive-beam facilities. 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.
Experimental progress is intimately linked with theory, where novel and practical approaches are a hallmark of the Surrey group. An outstanding feature, which is key to our group's research plans and is unique in the UK, is our powerful 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. To tackle these problems, 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. Much 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.
Planned Impact
Here we address more specifically the wider community who may benefit from our basic research.
A key current topic is that of nuclear security. Here our advanced experimental and theoretical techniques may help to address the needs of the security industry. In this regard we are well connected with AWE plc, including collaborative PhD students.
We have recently developed strong links with the National Physical Laboratory, where we enhance their capabilities in radionuclide metrology.
Sustainable energy production is another vital issue for society, and nuclear energy has an important role to play. We have made fundamental advances that lead to a better understanding of decay heat in nuclear reactors. Furthermore, our basic studies of both reaction processes and the structure of unstable nuclei may be important for future nuclear energy technologies.
Cancer diagnosis and treatment is of great importance. Our radiation-detector advances can lead to improved imaging systems, that benefit cancer and other medical treatments.
A key current topic is that of nuclear security. Here our advanced experimental and theoretical techniques may help to address the needs of the security industry. In this regard we are well connected with AWE plc, including collaborative PhD students.
We have recently developed strong links with the National Physical Laboratory, where we enhance their capabilities in radionuclide metrology.
Sustainable energy production is another vital issue for society, and nuclear energy has an important role to play. We have made fundamental advances that lead to a better understanding of decay heat in nuclear reactors. Furthermore, our basic studies of both reaction processes and the structure of unstable nuclei may be important for future nuclear energy technologies.
Cancer diagnosis and treatment is of great importance. Our radiation-detector advances can lead to improved imaging systems, that benefit cancer and other medical treatments.
Organisations
Publications
Blank B
(2016)
New neutron-deficient isotopes from Kr 78 fragmentation
in Physical Review C
Mutschler A
(2016)
Spectroscopy of P 35 using the one-proton knockout reaction
in Physical Review C
Johnson R
(2015)
Erratum: Spin dependence of the incident channel distorted wave in the theory of the A ( d , p ) B reaction [Phys. Rev. C 91 , 054604 (2015)]
in Physical Review C
Spieker M
(2019)
Experimental identification of the T = 1 , J p = 6 + state of Co 54 and isospin symmetry in A = 54 studied via one-nucleon knockout reactions
in Physical Review C
Sellahewa R
(2014)
Isovector properties of the Gogny interaction
in Physical Review C
Lay J
(2016)
Evidence of strong dynamic core excitation in C 19 resonant break-up
in Physical Review C
Crawford H
(2017)
Unexpected distribution of ? 1 f 7 / 2 strength in Ca 49
in Physical Review C
Barbieri C
(2022)
Gorkov algebraic diagrammatic construction formalism at third order
in Physical Review C
Tain JL
(2015)
Enhanced ?-Ray Emission from Neutron Unbound States Populated in ß Decay.
in Physical review letters
Chen ZQ
(2019)
Proton Shell Evolution below ^{132}Sn: First Measurement of Low-Lying ß-Emitting Isomers in ^{123,125}Ag.
in Physical review letters
Idini A
(2019)
Ab Initio Optical Potentials and Nucleon Scattering on Medium Mass Nuclei.
in Physical review letters
Lotay G
(2016)
Direct Measurement of the Astrophysical ^{38}K(p,?)^{39}Ca Reaction and Its Influence on the Production of Nuclides toward the End Point of Nova Nucleosynthesis.
in Physical review letters
Goigoux T
(2016)
Two-Proton Radioactivity of ^{67}Kr.
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
Estienne M
(2019)
Updated Summation Model: An Improved Agreement with the Daya Bay Antineutrino Fluxes.
in Physical review letters
Gade A
(2019)
Is the Structure of ^{42}Si Understood?
in Physical review letters
Milne SA
(2016)
Isospin Symmetry at High Spin Studied via Nucleon Knockout from Isomeric States.
in Physical review letters
Guadilla V
(2019)
Large Impact of the Decay of Niobium Isomers on the Reactor ? ¯ e Summation Calculations
in Physical Review Letters
Paul N
(2019)
Prominence of Pairing in Inclusive (p,2p) and (p,pn) Cross Sections from Neutron-Rich Nuclei.
in Physical review letters
Caballero-Folch R
(2016)
First Measurement of Several ß-Delayed Neutron Emitting Isotopes Beyond N=126.
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
Fruet G
(2020)
Advances in the Direct Study of Carbon Burning in Massive Stars.
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
Margerin V
(2015)
Inverse Kinematic Study of the (26g)Al(d,p)(27)Al Reaction and Implications for Destruction of (26)Al in Wolf-Rayet and Asymptotic Giant Branch Stars.
in Physical review letters
Welker A
(2017)
Binding Energy of ^{79}Cu: Probing the Structure of the Doubly Magic ^{78}Ni from Only One Proton Away.
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
Revel A
(2020)
Extending the Southern Shore of the Island of Inversion to F 28
in Physical Review Letters
Kolos K
(2016)
Direct Lifetime Measurements of the Excited States in (72)Ni.
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
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
Podolyák Z
(2016)
Role of the ? Resonance in the Population of a Four-Nucleon State in the ^{56}Fe?^{54}Fe Reaction at Relativistic Energies.
in Physical review letters
Lapoux V
(2016)
Radii and Binding Energies in Oxygen Isotopes: A Challenge for Nuclear Forces.
in Physical review letters
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
Walker PM
(2020)
Properties of ^{187}Ta Revealed through Isomeric Decay.
in Physical review letters
Chen S
(2019)
Quasifree Neutron Knockout from ^{54}Ca Corroborates Arising N=34 Neutron Magic Number.
in Physical review letters
Atanasov D
(2015)
Precision Mass Measurements of ^{129-131}Cd and Their Impact on Stellar Nucleosynthesis via the Rapid Neutron Capture Process.
in Physical review letters
Bazin D
(2017)
Doubly Magic Nickel
in Physics
Ozturk F
(2019)
New test of modulated electron capture decay of hydrogen-like 142Pm ions: Precision measurement of purely exponential decay
in Physics Letters B
Holl M
(2019)
Quasi-free neutron and proton knockout reactions from light nuclei in a wide neutron-to-proton asymmetry range
in Physics Letters B
Ota S
(2020)
Decay properties of 22Ne + a resonances and their impact on s-process nucleosynthesis
in Physics Letters B
Gade A
(2020)
In-beam ?-ray spectroscopy at the proton dripline: 40Sc
in Physics Letters B
Watanabe H
(2016)
Long-lived K isomer and enhanced ? vibration in the neutron-rich nucleus 172Dy: Collectivity beyond double midshell
in Physics Letters B
Berry T
(2019)
Investigation of the ?n = 0 selection rule in Gamow-Teller transitions: The ß-decay of 207Hg
in Physics Letters B
Bocchi G
(2016)
The mutable nature of particle-core excitations with spin in the one-valence-proton nucleus 133 Sb
in Physics Letters B
Pereira-López X
(2020)
Low-lying single-particle structure of 17C and the N = 14 sub-shell closure
in Physics Letters B
Fernández-Domínguez B
(2018)
Re-examining the transition into the N = 20 island of inversion: Structure of 30Mg
in Physics Letters B
Sun Y
(2020)
Restoration of the natural E(1/2 1 + ) - E(3/2 1 + ) energy splitting in odd-K isotopes towards N = 40
in Physics Letters B
Browne F
(2015)
Lifetime measurements of the first 2 + states in 104,106Zr: Evolution of ground-state deformations
in Physics Letters B
Moschini L
(2021)
Tracing the dynamical interplay of low-energy reaction processes of exotic nuclei using a two-center molecular continuum
in Physics Letters B
Nishimura N
(2016)
Impact of the first-forbidden ß decay on the production of A~ 195 r-process peak
in Physics Letters B
Description | The grant has funded experimental work at RIKEN, TRIUMF, Argonne, GANIL and other international laboratories and theoretical collaborations with RIKEN, MSU, GSI and other major centres. New isomeric states in exotic nuclei were discovered and much-improved measurements of nuclear astrophysical cross sections were determined. |
Exploitation Route | Outputs are published in the leading scientific journals and will feed into improved nuclear astrophysics and nuclear structure theories. |
Sectors | Other |
URL | http://www.nucleartheory.net/NPG/recent_publications.htm |