Edinburgh Nuclear Physics Group Consolidated Grant Proposal
Lead Research Organisation:
University of Edinburgh
Department Name: Sch of Physics and Astronomy
Abstract
The Greeks used to say matter was indivisible. This notion took a beating when Rutherford and co-workers showed that elements could be transformed by nuclear reactions. For a while it was thought that all the elements were produced in the big bang. Scientists such as Bethe and Hoyle showed in fact that nearly all the elements are produced in nuclear reactions in stars, which also for example make our sun shine. We are still seeking to understand the means by which these elements are produced and how stars evolve during their lifetime. This problem is being addressed through new detailed observations of stellar chemical abundances in the cosmos with telescopes, and here on earth, by trying to re-create the reactions occurring in stars.
Elements can be produced by nuclear reactions in highly explosive, hot dense environments such as found in supernovae explosions, with the material subsequently thrown out into the cosmos, and eventually fetching up in locations such as our sun or the interstellar medium. In explosive environments it is the reactions and properties of unstable nuclei that are critical for understanding element production and energy generation in these processes. One can make an analogy with a river in full flood bursting its banks and then flowing in completely different directions: normally life is quiescent and stable, but it is often in these violent episodes that permanent imprints remain. New generation accelerator facilities are able to produce an increasingly large number of the key radioactive nuclear species involved in these explosive processes. So we can now study the reactions occurring in the stars and the subsequent decay paths of nuclei that end up in the stable isotopes we see around us. The elemental abundances of these stable isotopes provide coded information on their often violent history. This new information is required to discover the nature of the explosive environments in which such elements were first formed.
In the longer quiescent phase of stars, their evolution is controlled by nuclear reactions occurring at much lower temperatures and densities, and which involve stable isotopes. You might think these would be easier to study, but because the reactions occur at much lower temperatures and densities nuclear fusion is strongly inhibited by the repulsions between the positively charged nuclei, and can only take place with very low probability by quantum tunneling. This leads to low experimental yields, and the signature for the fusion reaction is swamped by reactions produced by cosmic rays. So we are now working at the only underground nuclear astrophysics accelerator laboratory in the world where the rock above forms a protective canopy for our experiments.
The structure of stars is intimately tied to the structure of nuclear matter. Neutron stars, a relic of supernovae explosions can usefully be viewed as gigantic nuclei held together by the gravitational force. Precision experiments we are performing with high energy point-like fundamental particle beams are revealing a skin of almost pure neutron matter around the nucleus whose precise thickness tells us about the likely structure of neutron stars. These beams also allow us to peer inside a proton and explore the different ways the quarks inside can re-arrange themselves. These arrangements take the form of different excited states known as nucleon resonances. We think we have a good theory, QCD, to understand the proton but in fact it predicts many more resonances than we observe, so we are going to search for the new ones! Even more exotic configurations, are the so-called hybrids, in which the glue binding quarks together combines with quarks to produce a new form of matter. This would be a major discovery.
Elements can be produced by nuclear reactions in highly explosive, hot dense environments such as found in supernovae explosions, with the material subsequently thrown out into the cosmos, and eventually fetching up in locations such as our sun or the interstellar medium. In explosive environments it is the reactions and properties of unstable nuclei that are critical for understanding element production and energy generation in these processes. One can make an analogy with a river in full flood bursting its banks and then flowing in completely different directions: normally life is quiescent and stable, but it is often in these violent episodes that permanent imprints remain. New generation accelerator facilities are able to produce an increasingly large number of the key radioactive nuclear species involved in these explosive processes. So we can now study the reactions occurring in the stars and the subsequent decay paths of nuclei that end up in the stable isotopes we see around us. The elemental abundances of these stable isotopes provide coded information on their often violent history. This new information is required to discover the nature of the explosive environments in which such elements were first formed.
In the longer quiescent phase of stars, their evolution is controlled by nuclear reactions occurring at much lower temperatures and densities, and which involve stable isotopes. You might think these would be easier to study, but because the reactions occur at much lower temperatures and densities nuclear fusion is strongly inhibited by the repulsions between the positively charged nuclei, and can only take place with very low probability by quantum tunneling. This leads to low experimental yields, and the signature for the fusion reaction is swamped by reactions produced by cosmic rays. So we are now working at the only underground nuclear astrophysics accelerator laboratory in the world where the rock above forms a protective canopy for our experiments.
The structure of stars is intimately tied to the structure of nuclear matter. Neutron stars, a relic of supernovae explosions can usefully be viewed as gigantic nuclei held together by the gravitational force. Precision experiments we are performing with high energy point-like fundamental particle beams are revealing a skin of almost pure neutron matter around the nucleus whose precise thickness tells us about the likely structure of neutron stars. These beams also allow us to peer inside a proton and explore the different ways the quarks inside can re-arrange themselves. These arrangements take the form of different excited states known as nucleon resonances. We think we have a good theory, QCD, to understand the proton but in fact it predicts many more resonances than we observe, so we are going to search for the new ones! Even more exotic configurations, are the so-called hybrids, in which the glue binding quarks together combines with quarks to produce a new form of matter. This would be a major discovery.
Planned Impact
This proposal outlines a wide-ranging, innovative and internationally competitive research programme. The delivery of this programme depends critically on the group's 25+ years of intellectual investment in, and exploitation of, state of the art experimental techniques using advanced silicon radiation detector and instrumentation technologies.
The requirements of the UK nuclear physics research programme have led to the development of large area silicon strip detectors using both very thin (c. 20 micron) and very thick ( > 1mm) wafers which are now commercially available from the UK company Micron Semiconductor Ltd. These capabilities provide Micron Semiconductor Ltd with a range of unique product features and access to a large, worldwide export market.
Our continuing collaboration with the STFC Daresbury and Rutherford Laboratories in the development of advanced instrumentation systems (e.g. Advanced Implantation Detector Array - AIDA) directly benefits the UK science base by providing access to advanced technology for applications and maintains core skills and expertise for the UK science community.
The research and development programme for the Edinburgh nucleon polarimeter at MAMI has prompted new ideas for improving Positron Emission Tomography (PET) imaging. This has led to the award of STFC Follow on Funding and direct collaboration with clinicians and medical physicists.
Within the BRIKEN collaboration, we will measure beta-delayed neutron emission probabilities (Pn-values) for a large number of unstable isotopes for the first time. Pn-values affect the dynamic time response and the decay-heat in nuclear reactors, so this experimental programme will provide necessary nuclear data from the point of view of nuclear reactor operation and safety, and for the design of future reactors with advanced fuel cycles.
The nuclear physics research programme provides excellent training opprtunities for PhD students. The size and scope of nuclear physics experiments means that PhD students must actively engage with all of the scientific and technical aspects of the experiments from beam transport to the experimental target, to the analysis and interpretation of experimental data, and all points in between. The research programme produces young scientists with a wide range of scientific and technical competencies with employment opportunities in industry, business and academia.
The requirements of the UK nuclear physics research programme have led to the development of large area silicon strip detectors using both very thin (c. 20 micron) and very thick ( > 1mm) wafers which are now commercially available from the UK company Micron Semiconductor Ltd. These capabilities provide Micron Semiconductor Ltd with a range of unique product features and access to a large, worldwide export market.
Our continuing collaboration with the STFC Daresbury and Rutherford Laboratories in the development of advanced instrumentation systems (e.g. Advanced Implantation Detector Array - AIDA) directly benefits the UK science base by providing access to advanced technology for applications and maintains core skills and expertise for the UK science community.
The research and development programme for the Edinburgh nucleon polarimeter at MAMI has prompted new ideas for improving Positron Emission Tomography (PET) imaging. This has led to the award of STFC Follow on Funding and direct collaboration with clinicians and medical physicists.
Within the BRIKEN collaboration, we will measure beta-delayed neutron emission probabilities (Pn-values) for a large number of unstable isotopes for the first time. Pn-values affect the dynamic time response and the decay-heat in nuclear reactors, so this experimental programme will provide necessary nuclear data from the point of view of nuclear reactor operation and safety, and for the design of future reactors with advanced fuel cycles.
The nuclear physics research programme provides excellent training opprtunities for PhD students. The size and scope of nuclear physics experiments means that PhD students must actively engage with all of the scientific and technical aspects of the experiments from beam transport to the experimental target, to the analysis and interpretation of experimental data, and all points in between. The research programme produces young scientists with a wide range of scientific and technical competencies with employment opportunities in industry, business and academia.
Organisations
Publications
Sotty C
(2015)
(97)(37)Rb(60): The Cornerstone of the Region of Deformation around A ~ 100 [corrected].
in Physical review letters
Cavallaro M
(2015)
10Li low-lying resonances populated by one-neutron transfer
Slemer A
(2017)
22 Ne and 23 Na ejecta from intermediate-mass stars: the impact of the new LUNA rate for 22 Ne( p , ?) 23 Na
in Monthly Notices of the Royal Astronomical Society
Taggart M
(2019)
A direct measurement of the 17O(a,?)21Ne reaction in inverse kinematics and its impact on heavy element production
in Physics Letters B
Skowronski J
(2023)
Advances in radiative capture studies at LUNA with a segmented BGO detector
in Journal of Physics G: Nuclear and Particle Physics
Glorius J
(2019)
Approaching the Gamow Window with Stored Ions: Direct Measurement of ^{124}Xe(p,?) in the ESR Storage Ring.
in Physical review letters
Domingo-Pardo C
(2016)
Approaching the precursor nuclei of the third r-process peak with RIBs
in Journal of Physics: Conference Series
Trezzi D
(2017)
Big Bang 6 Li nucleosynthesis studied deep underground (LUNA collaboration)
in Astroparticle Physics
Albers M
(2016)
Corrigendum to: "Shape dynamics in neutron-rich Kr isotopes: Coulomb excitation of 92Kr, 94Kr and 96Kr" [Nucl. Phys. A 899 (2013) 1-28]
in Nuclear Physics A
Lederer-Woods C
(2021)
Destruction of the cosmic ? -ray emitter Al 26 in massive stars: Study of the key Al 26 ( n , a ) reaction
in Physical Review C
Lederer-Woods C
(2021)
Destruction of the cosmic ? -ray emitter Al 26 in massive stars: Study of the key Al 26 ( n , p ) reaction
in Physical Review C
Bashkanov M
(2019)
Deuteron photodisintegration by polarized photons in the region of the d?(2380)
in Physics Letters B
Depalo R
(2016)
Direct measurement of low-energy Ne 22 ( p , ? ) Na 23 resonances
in Physical Review C
Kröger F
(2020)
Electron capture of Xe 54 + in collisions with H 2 molecules in the energy range between 5.5 and 30.9 MeV/u
in Physical Review A
Paudyal D
(2020)
Extracting the spin polarizabilities of the proton by measurement of Compton double-polarization observables
in Physical Review C
Piatti D
(2022)
First direct limit on the 334 keV resonance strength in $$^{22}$$Ne($$\alpha $$,$$\gamma $$)$$^{26}$$Mg reaction
in The European Physical Journal A
Caballero-Folch R
(2016)
First Measurement of Several ß-Delayed Neutron Emitting Isotopes Beyond N=126.
in Physical review letters
Bruno C
(2019)
Improved astrophysical rate for the 18O(p,a)15N reaction by underground measurements
in Physics Letters B
Bruno CG
(2016)
Improved Direct Measurement of the 64.5 keV Resonance Strength in the ^{17}O(p,a)^{14}N Reaction at LUNA.
in Physical review letters
Skowronski J
(2023)
Improved S factor of the C 12 ( p , ? ) N 13 reaction at E = 320 - 620 keV and the 422 keV resonance
in Physical Review C
Cavallaro M
(2017)
Investigation of the ^{10}Li shell inversion by neutron continuum transfer reaction.
in Physical review letters
Pantaleo F
(2021)
Low-energy resonances in the O 18 ( p , ? ) 19 F reaction
in Physical Review C
Tomlinson JR
(2015)
Measurement of 23Na(a,p)26Mg at Energies Relevant to 26Al Production in Massive Stars.
in Physical review letters
Cividini F
(2022)
Measurement of the helicity dependence for single $$\pi ^{0}$$ photoproduction from the deuteron
in The European Physical Journal A
Reifarth R
(2016)
Nuclear astrophysics with radioactive ions at FAIR
in Journal of Physics: Conference Series
Doherty D
(2015)
Nuclear transfer reaction measurements at the ESR-for the investigation of the astrophysical 15 O( a , ? ) 19 Ne reaction
in Physica Scripta
Lugaro M
(2017)
Origin of meteoritic stardust unveiled by a revised proton-capture rate of 17O
in Nature Astronomy
Lestinsky M
(2016)
Physics book: CRYRING@ESR
in The European Physical Journal Special Topics
Cavallaro M
(2016)
Preliminary study of the 10 Li nucleus via one-neutron transfer
in EPJ Web of Conferences
Bruno C
(2015)
Resonance strengths in the 17,18O(p, a)14,15N reactions and background suppression underground Commissioning of a new setup for charged-particle detection at LUNA
in The European Physical Journal A
Boeltzig A
(2016)
Shell and explosive hydrogen burning Nuclear reaction rates for hydrogen burning in RGB, AGB and Novae
in The European Physical Journal A
Bashkanov M
(2020)
Signatures of the d^{*}(2380) Hexaquark in d(?,pn[over ?]).
in Physical review letters
McCleskey E
(2016)
Simultaneous measurement of ß -delayed proton and ? decay of P 27
in Physical Review C
Kahl D
(2019)
Single-particle shell strengths near the doubly magic nucleus 56Ni and the 56Ni(p,?)57Cu reaction rate in explosive astrophysical burning
in Physics Letters B
Margerin V
(2014)
Study of the Ti 44 ( a , p ) V 47 reaction and implications for core collapse supernovae
in Physics Letters B
Vidaña I
(2017)
The $d^*(2380)$ in neutron stars - a new degree of freedom?
Vidaña I
(2018)
The d?(2380) in Neutron Stars - A New Degree of Freedom?
in Physics Letters B
Straniero O
(2017)
The impact of the revised 17 O(p, a ) 14 N reaction rate on 17 O stellar abundances and yields
in Astronomy & Astrophysics
Varga L
(2020)
Towards background-free studies of capture reaction in a heavy-ion storage ring
in Journal of Physics: Conference Series
Butler P
(2016)
TSR: A Storage Ring for HIE-ISOLDE
in Acta Physica Polonica B
Gervino G
(2016)
Ultra-sensitive ?-ray spectroscopy set-up for investigating primordial lithium problem
in Nuclear Instruments and Methods in Physics Research Section A: Accelerators, Spectrometers, Detectors and Associated Equipment
Caballero-Folch R
(2017)
ß -decay half-lives and ß -delayed neutron emission probabilities for several isotopes of Au, Hg, Tl, Pb, and Bi, beyond N = 126
in Physical Review C
Description | discovered key resonance for destruction of cosmic gamma ray emitter developed new transfer reaction technique, first results show dramatic effect on abundances of heavy elements in novae ejecta studied destruction of cosmic gamma ray emitter by neutron destruction developed new storage ring technique to measure p process reactions |
Exploitation Route | the findings will be used in stellar models |
Sectors | Other |