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
Stevenson P
(2015)
Shapes and Dynamics from the Time-Dependent Mean Field
Grieser M
(2012)
Storage ring at HIE-ISOLDE Technical design report
in The European Physical Journal Special Topics
Browne F
(2023)
Interpretation of metastable states in the $$N>70$$ Zr region
in The European Physical Journal A
Arellano H
(2016)
Di-nucleon structures in homogeneous nuclear matter based on two- and three-nucleon interactions
in The European Physical Journal A
Carbone A
(2014)
Tensor force effects and high-momentum components in the nuclear symmetry energy
in The European Physical Journal A
Makek M
(2016)
Differential cross section measurement of the 12C(e,e'pp)10Beg.s. reaction
in The European Physical Journal A
Kankainen A
(2016)
Angle-integrated measurements of the 26Al (d, n)27Si reaction cross section: a probe of spectroscopic factors and astrophysical resonance strengths
in The European Physical Journal A
Minkov N
(2012)
Magnetic moments of K isomers as indicators of octupole collectivity
in The European Physical Journal A
Vidaña I
(2014)
Effect of Tensor Correlations on the Density Dependence of the Nuclear Symmetry Energy
in Symmetry
Mcfadden Johnjoe
(2015)
Good Vibrations
in SCIENTIST
Jiao C
(2012)
Competition between collective oblate rotation and non-collective prolate K isomerism in neutron-rich tungsten isotopes
in Science China Physics, Mechanics and Astronomy
Dracoulis GD
(2016)
Review of metastable states in heavy nuclei.
in Reports on progress in physics. Physical Society (Great Britain)
Nakhostin M
(2013)
A thermal neutron beam monitor based on avalanche counter
in Radiation Physics and Chemistry
Nakhostin M
(2013)
Use of commercial operational amplifiers in a low cost multi-channel preamplifier system
in Radiation Physics and Chemistry
Regan P
(2015)
Precision measurement of sub-nanosecond lifetimes of excited nuclear states using fast-timing coincidences with LaBr3(Ce) detectors
in Radiation Physics and Chemistry
Larijani C
(2015)
Progress towards the production of the 236gNp standard sources and competing fission fragment production
in Radiation Physics and Chemistry
Podolyák Z
(2014)
Studies of exotic nuclei with advanced radiation detectors
in Radiation Physics and Chemistry
Najem M
(2015)
Neutron production from flattening filter free high energy medical linac: A Monte Carlo study
in Radiation Physics and Chemistry
Tostevin J. A.
(2012)
Direct Reaction Probes of Single-Particle States and Correlations
in PROGRESS OF THEORETICAL PHYSICS SUPPLEMENT
Al-Khalili J
(2013)
Nature's quantum subways
in Physics World
Sanetullaev A
(2014)
Neutron spectroscopic factors of 55 Ni hole-states from ( p , d ) transfer reactions
in Physics Letters B
Benzoni G
(2012)
First measurement of beta decay half-lives in neutron-rich Tl and Bi isotopes
in Physics Letters B
Wilson E
(2015)
Core excitations across the neutron shell gap in 207Tl
in Physics Letters B
Sethi J
(2013)
Structure of nearly degenerate dipole bands in 108Ag
in Physics Letters B
Togano Y
(2016)
Interaction cross section study of the two-neutron halo nucleus 22 C
in Physics Letters B
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. |