Nuclear Physics consolidated grant

Lead Research Organisation: University of York
Department Name: Physics

Abstract

The atomic nucleus was 'discovered' by Ernest Rutherford a hundred years ago. It comprises the tiny massive core at the centre of the atom. We now know that the nucleus is composed of protons and neutrons, and that these particles are themselves comprised of quarks, but this does not allow us to make a complete prediction of the behaviour of any given nucleus or isotope. The system is too complex, involving three of the four forces: the electromagnetic, weak and strong nuclear forces. The behaviour of the nucleus is often described as an emergent phenomenon as it cannot be readily predicted from its component parts. This drives theoretical effort and the need to benchmark theory with precision measurements. Our group addresses several fascinating aspects of the atomic nucleus: We study nuclei on the very limits of stability, in particular those with an excess of protons, and those which have the same number of protons and neutrons (N=Z nuclei). These nuclei exhibit special symmetries and deviations from these symmetries tell us very detailed information on the validity of competing nuclear models. Such measurements are very challenging as these nuclei are very difficult to produce in any quantity to perform experiments on. Our programme uses some of the principal facilities for nuclear physics worldwide where such exotic nuclei can be produced. A further aspect of our research into the structure of the nucleus concerns the shape of the nucleus. It is a remarkable property of the nucleus that it can adopt different shapes: spherical, oblate (smartie-shaped) and prolate (rugby-ball shaped) often for a small costs in energy. Predicting the shape of a nucleus and how this shape evolves as the nucleus is excited (given more energy) is extremely challenging from a theoretical perspective. Determining nuclear shape experimentally can help to discriminate between competing models of the nucleus and pin down our theoretical understanding. The third strand of our research is into the origin of the chemical elements in stars, and the role played by nuclear physics in this question. Some elements and isotopes are only produced in very hot and exotic events such as exploding stars: novae and supernovae. In these events, a rapid series of nuclear reactions takes place. We seek to understand how rapidly such reactions take place by reproducing them in the laboratory. This is very challenging as many of the nuclei involved in these studies are themselves radioactive and difficult to produce. Nevertheless, we are able to advance our understanding of how the chemical elements are created.
 
Description This grant contained two key research themes. These were the studies of nuclear structure related to nuclei with roughly equal numbers of protons and neutrons and nuclear reactions that are important to a variety of different astrophysical processes.

We have made significant progress in our understanding of the production of radioactive fluorine in nova explosions. This isotope is important as its observation could provide constraints on the explosion mechanism, if the nuclear reaction rates are well enough known. Through a series of coordinated measurements, using direct measurements and studies of the relevant nuclear structure properties we have found that previously assumed properties of key nuclear states are in fact incorrect. We determined that states, previously assumed to interfere quantum mechanically, will not interfere, resulting in the uncertainty in the reaction rate being significantly reduced. In addition we found that a nuclear state, assumed to play a role in one of the destruction reactions, is insignificant. Overall we significantly reduced the uncertainty in the rate of destruction of radioactive fluorine, allowing better estimates of its final abundance to be made.

The radioisotope 26Al can be observed in the Galaxy through the gamma ray resulting from its decay and so maps of the Galaxy can be produced showing 26Al distribution. As 26Al was present during the formation of the Solar System, understanding its production in stars can help understand the conditions in which
the Solar System formed. 26Al is thought to be produced in massive stars and there are a small number of reactions affecting its abundance. One of these, the fusion of sodium and helium, had been measured and found to have a surprisingly high reaction rate.
We measured this reaction at two laboratories, TRIUMF (Canada) and Aarhus (Denmark), using complementary techniques and found the previously published rate to be incorrect by almost two orders of magnitude.

Key results for the proton rich nuclei include the first identification of the low-lying (low spin) excited states in the very exotic N=Z nucleus 92Pd (N=Z=46) and the interpretation of the states using the nuclear shell model in terms of a new neutron-proton spin-aligned coupling scheme. Such a feature is special to nuclei with equal numbers of neutrons and protons the protons and results from the particles occupying the same orbitals in the nuclear potential. Evidence for special effects related to the (isoscalar) neutron-proton interaction responsible for such an effect has been sought for many years. This work was reported in Nature, with additional related work on a special high-spin isomer in 96Cd (N=Z=48) being reported in Physical Review Letters. This interaction can have important consequences for nuclear structure and impact on nuclear synthesis processes associated with the rapid-proton capture process.

Other key findings of our nuclear structure work relate to the study of nuclei with opposite numbers of protons and neutrons (ie mirror nuclei). The isospin symmetry of the nuclear force results in near-identical behaviour between nuclei with opposite numbers of neutron and protons. Our work in such nuclei has demonstrated the need to include, in addition to the normal Coulomb term which is well known to break isospin symmetry, an isospin non-conserving (INC) term in the nuclear interaction for which the matrix elements have a strong dependence with the coupled angular momentum. The physical origin of this INC term is still not understood and further work is ongoing to see if it is required in regions other than the light fp shell (mass 40-54) nuclei, and also to determine whether the strength of the interaction required to fit the data remains constant or varies with the orbitals occupied (ie with increasing mass number). The ultimate goal is to understand the origin of this isospin non-conserving interaction.
Exploitation Route Several papers have been published as a result of this grant. These can be used by both the academic (and non-academic communities where appropriate) to further research in nuclear structure and nuclear astrophysics. Some of the results from the nuclear astrophysics and structure work will impact on astrophysics modelling for various types of explosive stellar processes. The knowledge gained will also impact on education via training of teachers and the many outreach activities carried out by members of the group.
Detector developments made for the nuclear structure research part of the programme covered by this grant have impacted on developments from our nuclear technology laboratory, which operates in conjunction with companies that use radiation detectors for various applications.
Sectors Education

 
Description Experimental results obtained have been used to test and improve models of nuclear structure physics and nuclear astrophysics in relation to explosive nuclear synthesis scenarios. Detector development work performed as part of the grant has led to further grants being submitted for applications based funding related to nuclear decommissioning and other nuclear technology applications.
First Year Of Impact 2014
Sector Education,Environment,Other
 
Description ENSAR
Amount € 24,000 (EUR)
Organisation Sixth Framework Programme (FP6) 
Sector Public
Country European Union (EU)
Start 01/2008 
End 12/2012
 
Description AGATA collaboration 
Organisation Daresbury Laboratory
Country United Kingdom of Great Britain & Northern Ireland (UK) 
Sector Private 
PI Contribution Work was carried out to simulate the performance of the AGATA demonstrator array for use with relativistic beams at GSI. Codes were developed and are currently stored at Daresbury laboratory under the supervision of Dr M Labiche.
Collaborator Contribution Collaborators from various countries involved with the AGATA spectrometer have contributed to the development work of the simulation codes. The spectrometer itself is funded by many different European countries, including the UK.
Impact Outcomes have been achieved by other research groups in the UK associated with the AGATA grants, notably Dr A Boston from the University of Liverpool and the nuclear physics team at the Daresbury laboratory. The work involved in developing the detectors used for AGATA and the processing of the signals has had impact on development of radiation detection methods in medical physics.
 
Description AGATA collaboration 
Organisation University of Brighton
Department Arts and Humanities
Country United Kingdom of Great Britain & Northern Ireland (UK) 
Sector Academic/University 
PI Contribution Work was carried out to simulate the performance of the AGATA demonstrator array for use with relativistic beams at GSI. Codes were developed and are currently stored at Daresbury laboratory under the supervision of Dr M Labiche.
Collaborator Contribution Collaborators from various countries involved with the AGATA spectrometer have contributed to the development work of the simulation codes. The spectrometer itself is funded by many different European countries, including the UK.
Impact Outcomes have been achieved by other research groups in the UK associated with the AGATA grants, notably Dr A Boston from the University of Liverpool and the nuclear physics team at the Daresbury laboratory. The work involved in developing the detectors used for AGATA and the processing of the signals has had impact on development of radiation detection methods in medical physics.
 
Description AGATA collaboration 
Organisation University of Liverpool
Country United Kingdom of Great Britain & Northern Ireland (UK) 
Sector Academic/University 
PI Contribution Work was carried out to simulate the performance of the AGATA demonstrator array for use with relativistic beams at GSI. Codes were developed and are currently stored at Daresbury laboratory under the supervision of Dr M Labiche.
Collaborator Contribution Collaborators from various countries involved with the AGATA spectrometer have contributed to the development work of the simulation codes. The spectrometer itself is funded by many different European countries, including the UK.
Impact Outcomes have been achieved by other research groups in the UK associated with the AGATA grants, notably Dr A Boston from the University of Liverpool and the nuclear physics team at the Daresbury laboratory. The work involved in developing the detectors used for AGATA and the processing of the signals has had impact on development of radiation detection methods in medical physics.
 
Description AGATA collaboration 
Organisation University of Manchester
Department Division of Infection, Immunity & Respiratory Medicine
Country United Kingdom of Great Britain & Northern Ireland (UK) 
Sector Academic/University 
PI Contribution Work was carried out to simulate the performance of the AGATA demonstrator array for use with relativistic beams at GSI. Codes were developed and are currently stored at Daresbury laboratory under the supervision of Dr M Labiche.
Collaborator Contribution Collaborators from various countries involved with the AGATA spectrometer have contributed to the development work of the simulation codes. The spectrometer itself is funded by many different European countries, including the UK.
Impact Outcomes have been achieved by other research groups in the UK associated with the AGATA grants, notably Dr A Boston from the University of Liverpool and the nuclear physics team at the Daresbury laboratory. The work involved in developing the detectors used for AGATA and the processing of the signals has had impact on development of radiation detection methods in medical physics.
 
Description AGATA collaboration 
Organisation University of Surrey
Department Section of Chronobiology
Country United Kingdom of Great Britain & Northern Ireland (UK) 
Sector Hospitals 
PI Contribution Work was carried out to simulate the performance of the AGATA demonstrator array for use with relativistic beams at GSI. Codes were developed and are currently stored at Daresbury laboratory under the supervision of Dr M Labiche.
Collaborator Contribution Collaborators from various countries involved with the AGATA spectrometer have contributed to the development work of the simulation codes. The spectrometer itself is funded by many different European countries, including the UK.
Impact Outcomes have been achieved by other research groups in the UK associated with the AGATA grants, notably Dr A Boston from the University of Liverpool and the nuclear physics team at the Daresbury laboratory. The work involved in developing the detectors used for AGATA and the processing of the signals has had impact on development of radiation detection methods in medical physics.
 
Description NEDA array 
Organisation National Institute for Nuclear Physics
Department Legnaro National Laboratories
Country Italy, Italian Republic 
Sector Public 
PI Contribution Studies related to the development of a new neutron array (NEDA) for use with high intensity stable beam and radioactive beam studies, in particular investigations of new readout devices for both solid and liquid scintillator neutron detectors.
Collaborator Contribution Testing, design and charactersiation of new detectors for the new NEDA array.
Impact Design of a full array has been performed. An interim design for a first phase of development of the new array is in the final stages of completion. Publications on monte carlo studies of the NEDA neutron detectors (in Nucl Instr. and Meth A,673, p 64 and a forthcoming publication on neutron-gamma discrimination tests with different photomultipliers (to be published in Nucl Instr. and Meth A767, p83, Dec 14)
Start Year 2010
 
Description Binding Blocks - University visits and widening participation 2016 
Form Of Engagement Activity Participation in an open day or visit at my research institution
Part Of Official Scheme? No
Geographic Reach National
Primary Audience Schools
Results and Impact University visits and widening participation (~700 participants):
Physics 50th Anniversary (~100 participants, Jan 2016); York College visit (~30, Mar 2016); Widening Participation event (~20, Mar 2016); University Open Days (~250, June 2016); Schools Physicists of the Year Awards (~200, June 2016); Widening Participation (~50, July 2016); Girls in Physics (12 participants, Aug 2016); Physics Review Anniversary (~100, Oct 2016).
Most of the visits were dominated by students in secondary schools. For each of the schools events, (part of) a Binding Blocks nuclear (Segre) chart was built by the participants, while undergraduate students, postgraduate researchers, and/or academics discuss foundational nuclear physics principles (including constituents of nuclei, decay and energy) in conjunction with cutting edge research across fundamental nuclear physics and nuclear astrophysics, as well as nuclear applications and nuclear medicine. The school students were very engaged in the activity, and reported learning of - and inspiration towards engaging further with - nuclear physics. Undergraduate and Postgraduate students (taking part in) delivering the events reported a greater confidence in communicating this area of physics. Visiting professionals, including those from the industry, showed a strong interest in the concepts, and a number of these participants requested further information for future engagement in the programme.
Year(s) Of Engagement Activity 2016
URL https://www.york.ac.uk/physics/public-and-schools/secondary/binding-blocks/
 
Description Binding Blocks Public Events 2015 
Form Of Engagement Activity Participation in an activity, workshop or similar
Part Of Official Scheme? No
Geographic Reach Local
Primary Audience Public/other audiences
Results and Impact Public event 2015 (~5,000 participants): European Researchers' Night - YorNight (5000+, Sep 2015). A Binding Blocks nuclear (Segre) chart was built by the participants, while undergraduate students, postgraduate researchers, and academics discuss foundational nuclear physics principles (including constituents of nuclei, decay and energy) in conjunction with cutting edge research across fundamental nuclear physics and nuclear astrophysics, as well as nuclear applications and nuclear medicine. The members of the public were very engaged in the activity, and both children and adults alike showed a great interest in the underlying physics and applications.
Year(s) Of Engagement Activity 2015
URL https://www.york.ac.uk/physics/public-and-schools/secondary/binding-blocks/
 
Description Binding Blocks Public Events 2016 
Form Of Engagement Activity Participation in an activity, workshop or similar
Part Of Official Scheme? No
Geographic Reach Regional
Primary Audience Public/other audiences
Results and Impact Public events 2016 (~10,000 participants):
Regional Big Bang Fair (2000+, Doncaster, June 2016); Family Fringe Day (1000+, June 2016); Three Minutes to Midnight (~200, June 2016); STFC Science Up Close Open Day (7000+ people, Daresbury Laboratory, July 2016); iThemba LABS Open Day (~150, Cape Town, South Africa, Sep 2016); Nuclear Science Day (~40, University of Guelph, Canada, Oct 2016).
For each of the public events, a Binding Blocks nuclear (Segre) chart was built by the participants, while undergraduate students, postgraduate researchers, and academics discuss foundational nuclear physics principles (including constituents of nuclei, decay and energy) in conjunction with cutting edge research across fundamental nuclear physics and nuclear astrophysics, as well as nuclear applications and nuclear medicine. The members of the public were very engaged in the activity, and both children and adults alike showed a great interest in the underlying physics and applications.
Year(s) Of Engagement Activity 2016
URL https://www.york.ac.uk/physics/public-and-schools/secondary/binding-blocks/
 
Description Binding Blocks Schools Events 2016 
Form Of Engagement Activity Participation in an activity, workshop or similar
Part Of Official Scheme? No
Geographic Reach International
Primary Audience Schools
Results and Impact Schools events 2016 (~160 participants):
Star Gazing, St Peter's School, York (~100, Jan 2016); Huntington School (~20, Mar 2016); Queen Ethelburga's School (~20, Mar 2016); Morsø Gymnasium, Denmark (~25, Dec 2016). For each of the schools events, (part of) a Binding Blocks nuclear (Segre) chart was built by the participants, while undergraduate students, postgraduate researchers, and/or academics discuss foundational nuclear physics principles (including constituents of nuclei, decay and energy) in conjunction with cutting edge research across fundamental nuclear physics and nuclear astrophysics, as well as nuclear applications and nuclear medicine. The school students were very engaged in the activity, and reported learning of - and inspiration towards engaging further with - nuclear physics. The sessions were furthermore integrated into the curriculum as an integral part of the students' learning of the material. Undergraduate and Postgraduate students (taking part in) delivering the events reported a greater confidence in communicating this area of physics.
Year(s) Of Engagement Activity 2016
URL https://www.york.ac.uk/physics/public-and-schools/secondary/binding-blocks/
 
Description Binding Blocks Student and Academic Promotion and Training 2016 
Form Of Engagement Activity Participation in an activity, workshop or similar
Part Of Official Scheme? No
Geographic Reach International
Primary Audience Professional Practitioners
Results and Impact Student and Academic promotion and training 2016 (~700 students and academics):
Department of Physics student-training day (~40 participants, May 2016). Institute of Physics Nuclear Physics Conference (~120, Liverpool, Apr 2016), Geometric Models of Nuclear Matter (~40, Canterbury, Sep 2016), International Nuclear Physics Conference (~400, Adelaide, Australia, Sep 2016), NUSTAR Week (~100, York, Sep 2016). Student-training day (Hull University, Nov 2016). Participation in conferences has yielded an international engagement in the Binding Blocks programme, with overseas funding currently being sought by collaborators and several public events already run overseas. Student training has developed the local UK team and thereby facilitated the numerous external events delivered subsequently.
Year(s) Of Engagement Activity 2016
URL https://www.york.ac.uk/physics/public-and-schools/secondary/binding-blocks/
 
Description Binding Blocks Teacher Training 2016 
Form Of Engagement Activity Participation in an activity, workshop or similar
Part Of Official Scheme? No
Geographic Reach National
Primary Audience Schools
Results and Impact Teacher Training Events organised jointly with the National STEM Learning Centre 2016 (~130 teachers and technicians): Full science programme for CERN Teachers Day (~50, NSLC, June 2016) and workshop at York Physics Day (~20, NSLC, June 2016). Contributions to three other courses at NSLC (June 2016): New and Aspiring Primary Science Specialists (~25); Wakefield Academy Group Course (~15); and School Technicians Course (~20). For each of the training events, a 7 metre Binding Blocks nuclear (Segre) chart was wither built by the participants or engaged with, while undergraduate students, postgraduate researchers, academics, and/or learning specialists discuss the foundational nuclear physics principles (including constituents of nuclei, decay and energy) in conjunction with cutting edge research across fundamental nuclear physics and nuclear astrophysics, as well as nuclear applications and nuclear medicine. The school teachers were very engaged in the activity, and developed ideas for integration into the physics curriculum (as well as mathematics and chemistry) at both GCSE and A-level. Undergraduate and Postgraduate students (taking part in) delivering the events reported a greater confidence in communicating this area of physics. Staff members at the NSLC were furthermore impacted by the scale of the display, and organisers (at NSLC) reported a general buzz among staff members as a result of this.
Year(s) Of Engagement Activity 2016
URL https://www.york.ac.uk/physics/public-and-schools/secondary/binding-blocks/
 
Description Binding Blocks Website 
Form Of Engagement Activity Engagement focused website, blog or social media channel
Part Of Official Scheme? No
Geographic Reach International
Primary Audience Schools
Results and Impact Binding Blocks website (developed 2016). This includes event tracking and embedded twitter feed.
Year(s) Of Engagement Activity 2016
URL https://www.york.ac.uk/physics/bindingblocks/
 
Description Binding Blocks Youtube Channel 
Form Of Engagement Activity Engagement focused website, blog or social media channel
Part Of Official Scheme? No
Geographic Reach National
Primary Audience Schools
Results and Impact Development of video material available on the Binding Blocks YouTube channel. These videos include: Binding Blocks Promotional Video; Binding Blocks Introduction; Tour of the Stable Isotopes; Path to Stability; Fragmentation: Ni58 to Co-52; and Isotopic abundance simulation this NuGrid. Apart from the impact on schools, students, teachers, collaborators, and the public, requests for further participation includes contact from Channel4 producer Wall-to-Wall, resulting in contributions to the Child-Genius 2017 show, to be screened in 2017.
Year(s) Of Engagement Activity 2016
URL https://www.youtube.com/channel/UCvIXlFgJyGh4Jle_4_KE2aA
 
Description International conference on nuclear structure physics - Oak Ridge 
Form Of Engagement Activity A talk or presentation
Part Of Official Scheme? No
Geographic Reach International
Primary Audience Professional Practitioners
Results and Impact Research talk to nuclear physicists
Year(s) Of Engagement Activity 2016
 
Description International conference on nuclear structure physics, HIAS 2015 
Form Of Engagement Activity A talk or presentation
Part Of Official Scheme? No
Geographic Reach International
Primary Audience Professional Practitioners
Results and Impact Research talk presented to nuclear physicists.
Year(s) Of Engagement Activity 2015
 
Description Making Stars: Fusion 
Form Of Engagement Activity A magazine, newsletter or online publication
Part Of Official Scheme? No
Geographic Reach National
Primary Audience Schools
Results and Impact Educational material (lesson plans) for integration of nuclear fusion and nuclear astrophysics into the school curriculum. The teaching resource is directed towards secondary school teachers, in particular A-level Physics. The material is published on the STEM CPD Resource network and will be used in conjunction with a video featuring Dr Kim Cave-Aland, a control engineer at Culham Centre for Fusion Energy (CCFE). Quotes from the material include:
"When you tell people you make stars for a living, their heads turn and their mouths open."
"Fusion takes place in the centre of stars across the universe. The Making stars resource contains curriculum linked activities on nuclear fusion, binding energy, radioactivity and the hot CNO cycle in stars. The CNO cycle is the predominant fusion process in stars larger than the Sun. The main activity involves students in the classroom mapping out a real-time hot CNO fusion cycle on the classroom floor."
Available online 13th March 2017.
Year(s) Of Engagement Activity 2017
URL https://www.stem.org.uk/rx6zw6
 
Description Nuclear physics outreach work 
Form Of Engagement Activity Participation in an activity, workshop or similar
Part Of Official Scheme? No
Geographic Reach National
Primary Audience Schools
Results and Impact For the last ten years, I have been involved in a whole range of outreach activities related to nuclear physics, from lectures to local groups e.g. astronomical societies to lectures at major science festivals. A major focus has been on providing continuous professional development courses for teachers. These have taken place at several science learning centres including National Science Learning Centre in York. In addition, they have been given at Rutherford Lab and elsewhere. Around 500 teachers have been reached over the years.
Year(s) Of Engagement Activity 2006,2007,2008,2009,2010