Determining the role of non-axial deformation on proton decays; DPUNS - A Differential Plunger for Unbound Nuclear States.
Lead Research Organisation:
University of Manchester
Department Name: Physics and Astronomy
Abstract
This grant will further our understanding of one of the fundamental limits of nuclear stability. As more and more protons are added to a nucleus there comes a point at which the nucleus can no longer hold on to the last proton. This point is called the proton drip line. The last proton will usually be re-emitted in a very short time, on the scale of milliseconds or microseconds, after it has been absorbed. Nevertheless, excited states which decay by gamma-ray emission, on a picosecond time scale, can still exist in proton-unbound nuclei. In this grant we will characterise these excited states by building a new detector, DPUNS, which will uniquely allow the measurement of their lifetimes. This in turn permits, for the first time, the determination of the shapes of proton-unbound nuclei. Since the proton emission half-life depends sensitively on the shape of the nucleus, a consistent understanding of proton decay is our objective. This proposal contains a collaborative aspect with some of the world's experts in proton decays. Together, we will perform new calculations with unique new data to examine the role of asymmetric nuclear shapes on the proton emission rates and thereby, learn about the binding of the nuclear force. This is a challenging proposal which has the potential to bring about a step change in our ability to investigate nuclear structure beyond the proton drip line.
People |
ORCID iD |
David Matthew Cullen (Principal Investigator) |
Publications
Procter M
(2011)
High- K four-quasiparticle states in Gd 138
in Physical Review C
Wood R
(2017)
Three-quasiparticle isomer in Ta 173 and the excitation energy dependence of K -forbidden transition rates
in Physical Review C
Taylor M
(2013)
Competing single-particle and collective states in the low-energy structure of 113 I
in Physical Review C
Hodge D
(2016)
Deformation of the proton emitter Cs 113 from electromagnetic transition and proton-emission rates
in Physical Review C
Astier A
(2013)
First proton-pair breaking in semi-magic nuclei beyond 132 Sn and 208 Pb: Configuration of the long-lived isomer of 217 Pa
in Physical Review C
Grahn T
(2016)
Excited states and reduced transition probabilities in Os 168
in Physical Review C
Cullen D
(2011)
Discovery of a 10 µ s isomeric state in 63 139 Eu
in Physical Review C
Giles M
(2019)
Probing isospin symmetry in the ( Fe 50 , Mn 50 , Cr 50 ) isobaric triplet via electromagnetic transition rates
in Physical Review C
Lane J
(2013)
ß -delayed fission of 186 , 188 Bi isotopes
in Physical Review C
Zhang Y
(2012)
High-spin proton alignments and evidence for a second band with enhanced deformation in 171 Hf
in Physical Review C
Description | In this award, a new differential plunger device was built which enable the lifetime of nuclear states in exotic nuclei to be determined for the first time. This information was used to guid nuclear theory and gain a better understanding of how proton are emitted from exotic nuclei at the limits of nuclear existence. |
Exploitation Route | The new device is being used in collaboration by other international users to further their research at the moment in Finland. |
Sectors | Education Electronics |
Description | STFC Industrial CASE Studentship Panel (Dave Cullen) |
Geographic Reach | National |
Policy Influence Type | Membership of a guideline committee |
URL | https://stfc.ukri.org/funding/studentships/industrial-case-studentships/ |
Description | Nuclear physics consolidated grant 2014 |
Amount | £1,300,000 (GBP) |
Funding ID | ST/L005794/1 |
Organisation | Science and Technologies Facilities Council (STFC) |
Sector | Public |
Country | United Kingdom |
Start | 07/2014 |
End | 09/2018 |
Title | A new charge plunger device to measure the lifetimes of excited nuclear states with transitions dominated by internal conversion |
Description | The DPUNS plunger device has been adapted to allow for a different method of measuring nuclear lifetimes that does not rely on the detection of gamma rays. Instead, the charge state distribution of excited nuclei is detected as a function of plunger distance. This allows for the measurement of nuclear lifetimes that depopulate through transitions that have a low rate of gamma ray emission, such as a in super-heavy nuclei and low energy transitions, that would not have been possible with the standard DPUNS plunger approach. This work is currently being prepared for publication. |
Type Of Material | Improvements to research infrastructure |
Year Produced | 2020 |
Provided To Others? | Yes |
Impact | The application of the charge plunger technique to DPUNS will allow for lifetime measurements to be made in super-heavy nuclei that were not previously accessible. There are a lack of experimental lifetime measurements for excited states in super-heavy nuclei, while there are several motivations for obtaining them. The application of this method with the adapted DPUNS plunger will allow for shell-gaps and deformation in super-heavy nuclei to be determined. |
URL | http://www.doi.org/10.1016/j.nima.2020.164454 |
Title | DPUNS - A new differential plunger device was constructed to measure the lifetime of exotic nuclear states. |
Description | DPUNS - A new differential plunger device was constructed to measure the lifetime of exotic nuclear states. This device enable the lifetime of nuclear states to be measured in exotic nuclei beyond the drip line for the first time. The device enable a new simultaneous theoretical approach to determining proton-emission and gamma-emission rates in nuclei. The plunger device was commissioned in Finland and is now used by a series of international groups to further their research. |
Type Of Material | Improvements to research infrastructure |
Year Produced | 2016 |
Provided To Others? | Yes |
Impact | The plunger device was commissioned in Finland and is now used by a series of international groups to measure liefeimte in nuclei beyond what was originally thought o be possible. A series of papers have been published in high-impact journals, Physical Review Letters, Physics Letters B and Physical Review C. |
Title | TPEN- A new triple-foil differential plunger device was constructed to measure the lifetime of exotic nuclear states. |
Description | TPEN- A new Triple Foil differential plunger device was constructed to measure the lifetime of exotic nuclear states. This device enable the lifetime of nuclear states to be measured in exotic nuclei and was able to reduce the beam time required by a factor of 4 over previous plunger devices. The plunger device was commissioned in Finland and is now used by a series of international groups to further their research. |
Type Of Material | Improvements to research infrastructure |
Year Produced | 2019 |
Provided To Others? | Yes |
Impact | Research papers have been produced based on this device. |
Title | Several large database of nuclear gamma-ray spectroscopy for lifetime analysis of particular isotopes. |
Description | These databases consist of collections of gamma-ray coincidence data for transitions between nuclear energy levels in a series of isotopes produced in heavy-ion fusion-evaporation reactions with large arrays of germanium detectors. The data are primarily constructed for analysing nuclear state lifetimes. |
Type Of Material | Database/Collection of data |
Year Produced | 2014 |
Provided To Others? | No |
Impact | Mainly publications and invited talks. |
Description | IFIN-HH, Romania |
Organisation | Horia Hulubei National Institute of Physics and Nuclear Engineering |
Country | Romania |
Sector | Public |
PI Contribution | Our collaboration performed lifetime measurements of excited states in the triaxial nucleus 163Ta using the DPUNS device. |
Collaborator Contribution | P. Petkov at IFIN-HH performed particle-triaxial rotor model calculations in order to describe the experimental lifetimes of 163Ta in a theoretical framework. The partners have also provided our collaboration with the codes themselves, which have since been developed by our collaboration. |
Impact | Experimental lifetimes in 163Ta have been successfully described by the particle-triaxial rotor model. The contributions from this collaboration are being prepared for publication. |
Start Year | 2019 |
Description | Univeristy of Jyvaskyla |
Organisation | University of Jyvaskyla |
Department | Department of Physics |
Country | Finland |
Sector | Academic/University |
PI Contribution | Brought the differential plunger to JYFL in order to carry out experiments with this device |
Collaborator Contribution | Collaboration supportedd this device and paid for some infrastructure. |
Impact | Many publications and support for additional STFC grant proposals |
Description | University of Cologne |
Organisation | University of Cologne |
Department | Department of Physics |
Country | Germany |
Sector | Academic/University |
PI Contribution | Collaboration on experiments involving plungers and differential plunger devices for lifetime measurements. |
Collaborator Contribution | The partner has provided expertise and knowledge to this collaboration. |
Impact | Several research papers |
Start Year | 2008 |