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
Pang D
(2013)
Rapid convergence of the Weinberg expansion of the deuteron stripping amplitude
in Physical Review C
Goddard P
(2015)
Fission dynamics within time-dependent Hartree-Fock: Deformation-induced fission
in Physical Review C
Pérez-Cerdán A
(2013)
Deformation of Sr and Rb isotopes close to the N = Z line via ß -decay studies using the total absorption technique
in Physical Review C
Goddard P
(2016)
Fission dynamics within time-dependent Hartree-Fock. II. Boost-induced fission
in Physical Review C
Shi Y
(2012)
Superdeformed multi-quasiparticle high- K states and possible isomers in Pb and Po isotopes
in Physical Review C
Carbone A
(2013)
Self-consistent Green's functions formalism with three-body interactions
in Physical Review C
Reed M
(2012)
Long-lived isomers in neutron-rich Z = 72 -76 nuclides
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
Shi Y
(2012)
High- K isomers in neutron-rich zirconium isotopes
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
Fracasso S
(2012)
Unrestricted Skyrme-tensor time-dependent Hartree-Fock model and its application to the nuclear response from spherical to triaxial nuclei
in Physical Review C
Randisi G
(2014)
Structure of 13 Be probed via secondary-beam reactions
in Physical Review C
Modamio V
(2013)
Lifetime measurements in neutron-rich 63 , 65 Co isotopes using the AGATA demonstrator
in Physical Review C
Isaule F
(2016)
Di-neutrons in neutron matter within a Brueckner-Hartree-Fock approach
in Physical Review C
Guadilla V
(2017)
Experimental study of Tc 100 ß decay with total absorption ? -ray spectroscopy
in Physical Review C
Banu A
(2012)
One-proton breakup of 24 Si and the 23 Al( p , ? ) 24 Si reaction in type I x-ray bursts
in Physical Review C
Swan T
(2012)
Hindered decays from a non-yrast four-quasiparticle isomer in 164 Er
in Physical Review C
Crawford H
(2017)
Unexpected distribution of ? 1 f 7 / 2 strength in Ca 49
in Physical Review C
Kobayashi N
(2012)
One- and two-neutron removal reactions from the most neutron-rich carbon isotopes
in Physical Review C
Morales A
(2013)
ß -delayed ? -ray spectroscopy of 203 , 204 Au and 200 - 202 Pt
in Physical Review C
Pardi C
(2013)
Continuum time-dependent Hartree-Fock method for giant resonances in spherical nuclei
in Physical Review C
Recchia F
(2016)
Neutron single-particle strengths at N = 40 , 42: Neutron knockout from Ni 68 , 70 ground and isomeric states
in Physical Review C
Nita C
(2014)
Fast-timing lifetime measurements of excited states in Cu 67
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
Taprogge J
(2015)
ß decay of Cd 129 and excited states in In 129
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. |