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
Regan PH
(2012)
From RISING to the DESPEC fast-timing project within NUSTAR at FAIR: sub-nanosecond nuclear timing spectroscopy with LaBr3 scintillators.
in Applied radiation and isotopes : including data, instrumentation and methods for use in agriculture, industry and medicine
Alharbi T
(2012)
Gamma-ray fast-timing coincidence measurements from the 18O+18O fusion-evaporation reaction using a mixed LaBr3-HPGe array.
in Applied radiation and isotopes : including data, instrumentation and methods for use in agriculture, industry and medicine
Browne F
(2015)
Gamma-ray Spectroscopy in the Vicinity of $^{108}$Zr
in Acta Physica Polonica B
Valencia E
(2014)
Gamma/neutron competition above the neutron separation energy in delayed neutron emitters
in EPJ Web of Conferences
Mcfadden Johnjoe
(2015)
Good Vibrations
in SCIENTIST
Chakraborty S
(2014)
Ground-state configuration of neutron-rich Aluminum isotopes through Coulomb Breakup
in EPJ Web of Conferences
Roberts O
(2013)
Half-life Measurements of Excited States in <sup><span class="cmr-7">132</span></sup>Te, <sup><span class="cmr-7">134</span></sup>Xe
in Acta Physica Polonica B
Mason P
(2012)
Half-life of the I p = 4 - intruder state in 34 P: M 2 transition strengths approaching the island of inversion
in Physical Review C
Mason P
(2013)
Half-life of the yrast 2 + state in 188 W: Evolution of deformation and collectivity in neutron-rich tungsten isotopes
in Physical Review C
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
Walker P
(2016)
High- K isomerism in rotational nuclei
in Physica Scripta
Shi Y
(2012)
High- K isomers in neutron-rich zirconium isotopes
in Physical Review C
Söderström P
(2012)
High-spin structure in 40 K
in Physical Review C
Bunce M
(2013)
High-spin study of the shell model nucleus 88 Y 49
in Physical Review C
Gonzalez-Boquera C
(2017)
Higher-order symmetry energy and neutron star core-crust transition with Gogny forces
in Physical Review C
Gonzalez-Boquera C
(2017)
Higher-order symmetry energy and neutron star core-crust transition with Gogny forces
Swan T
(2012)
Hindered decays from a non-yrast four-quasiparticle isomer in 164 Er
in Physical Review C
Grodner E
(2014)
Hindered Gamow-Teller decay to the odd-odd N=Z (62)Ga: absence of proton-neutron T=0 condensate in A=62.
in Physical review letters
Timofeyuk N
(2017)
Hyperspherical Harmonics Expansion on Lagrange Meshes for Bosonic Systems in One Dimension
in Few-Body Systems
Nishimura N
(2016)
Impact of the first-forbidden ß decay on the production of A~ 195 r-process peak
in Physics Letters B
Waldecker S
(2016)
Implications for ( d , p ) reaction theory from nonlocal dispersive optical model analysis of Ca 40 ( d , p ) Ca 41
in Physical Review C
Britton R
(2013)
Improving the effectiveness of a low-energy Compton suppression system
in Nuclear Instruments and Methods in Physics Research Section A: Accelerators, Spectrometers, Detectors and Associated Equipment
Cáceres L
(2012)
In-beam spectroscopic studies of the 44 S nucleus
in Physical Review C
Akber A
(2015)
Increased isomeric lifetime of hydrogen-like Os 192 m
in Physical Review C
Nara Singh B
(2012)
Influence of the n p interaction on the ß decay of 94 Pd
in Physical Review C
Minkov N
(2014)
Influence of the octupole mode on nuclear high- K isomeric properties
in Physica Scripta
Togano Y
(2016)
Interaction cross section study of the two-neutron halo nucleus 22 C
in Physics Letters B
Kucuk Y
(2014)
Intermediate-energy four-body breakup calculations for C 22
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
Browne F
(2023)
Interpretation of metastable states in the $$N>70$$ Zr region
in The European Physical Journal A
Collins SM
(2018)
Investigation of ?-? coincidence counting using the National Nuclear Array (NANA) as a primary standard.
in Applied radiation and isotopes : including data, instrumentation and methods for use in agriculture, industry and medicine
Berry T
(2019)
Investigation of the ?n = 0 selection rule in Gamow-Teller transitions: The ß-decay of 207Hg
in Physics Letters B
Walker P
(2017)
Isomer building blocks and K -forbidden decays
in Physica Scripta
Alexander T
(2015)
Isomeric Ratios in $^{206}$Hg
in Acta Physica Polonica B
Yuan C
(2016)
Isomerism in the "south-east" of 132Sn and a predicted neutron-decaying isomer in 129Pd
in Physics Letters B
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
Stevenson P
(2014)
Isoscalar and Isovector Giant Monopole Resonances from a Continuum Hartree-Fock Method
in EPJ Web of Conferences
Milne SA
(2016)
Isospin Symmetry at High Spin Studied via Nucleon Knockout from Isomeric States.
in Physical review letters
Cipollone A
(2013)
Isotopic chains around oxygen from evolved chiral two- and three-nucleon interactions.
in Physical review letters
Sellahewa R
(2014)
Isovector properties of the Gogny interaction
Sellahewa R
(2014)
Isovector properties of the Gogny interaction
in Physical Review C
Browne F
(2017)
K selection in the decay of the ( ? 5 2 [ 532 ] ? 3 2 [ 411 ] ) 4 - isomeric state in Zr 102
in Physical Review C
Modamio V
(2013)
Lifetime measurements in neutron-rich 63 , 65 Co isotopes using the AGATA demonstrator
in Physical Review C
Browne F
(2015)
Lifetime measurements of the first 2 + states in 104,106Zr: Evolution of ground-state deformations
in Physics Letters B
Alharbi T
(2015)
Lifetime of the yrast I p = 5 - state and E 1 hindrance in the transitional nucleus Ce 58 136
in Physical Review C
Flavigny F
(2013)
Limited asymmetry dependence of correlations from single nucleon transfer.
in Physical review letters
Reed M
(2012)
Long-lived isomers in neutron-rich Z = 72 -76 nuclides
in Physical Review C
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. |