Laser spectroscopy of Radioactive Isotopes
Lead Research Organisation:
University of Surrey
Department Name: Nuclear and Radiation Physics
Abstract
Nuclear properties such as the size and magnetic field strength slightly shift or perturb the orbits of the atomic electrons.These shifts are small and at the level of a part per million of the electron binding energies. They can be measured with great precision by a variety of techniques using tunable laser light, which can be controlled with part per billion precision. When the laser light is tuned to exactly match an electronic transition frequency, it resonantly excites an isotope of the selected element. The excited atom quickly decays with the emission of fluorescence light which may be detected by photomultipliers sensitive to single photons. In this way the frequency of the laser resonance can be measured experimentally. The analysis of the resonant frequencies across an isotope series allows us to deduce the change in nuclear size as a function of neutron number. It is possible to detect the change of the proton distribution caused by the removal of a single neutron. The same data can show in a clear way whether the nucleus is changing its shape as neutrons are added or subtracted. The magnetic field strength around the nucleus, also measured in these experiments, is produced by the motion of both protons and neutrons. The theory of the magnetic field is well understood and clear conclusions can be drawn about the nucleon orbits occupied by the protons and neutrons. Thus the laser method provides fundamental information on basic properties of the nucleus - size, shape, magnetic properties, nuclear 'spin' angular momentum - which helps to refine our theoretical approaches to explain observed properties, and predict properties of nuclei we can not yet synthesize in the laboratory. The predictive power of these theories is very important. Many of the nuclei unavailable for study on Earth are involved in supernova processes. We cannot begin to understand the processes without first having an understanding of the nuclei involved. The laser techniques we
People |
ORCID iD |
Paul Stevenson (Principal Investigator) |
Publications
Alharbi T
(2015)
Lifetime of the yrast I p = 5 - state and E 1 hindrance in the transitional nucleus Ce 58 136
in Physical Review C
Alharbi T
(2013)
Electromagnetic transition rates in the N = 80 nucleus 58 138 Ce
in Physical Review C
Bunce M
(2013)
High-spin study of the shell model nucleus 88 Y 49
in Physical Review C
Goddard PM
(2013)
Charge radius isotope shift across the N=126 shell gap.
in Physical review letters
Dutra M
(2012)
Skyrme interaction and nuclear matter constraints
in Physical Review C
Avgoulea M
(2011)
Nuclear charge radii and electromagnetic moments of radioactive scandium isotopes and isomers
in Journal of Physics G: Nuclear and Particle Physics
Nomura K
(2011)
Spectroscopic calculations of the low-lying structure in exotic Os and W isotopes
in Physical Review C
Description | We gained an understanding of how the interaction between protons and neutron in the nucleus leads to the characteristic size of each nucleus, particular as one adds neutrons, one by one, to examine an isotopic chain |
Exploitation Route | Details of nuclear states may be used in the longer term in quantum technology devices. |
Sectors | Energy |
Description | Nuclear Physics Rolling grant scheme |
Amount | £2,294,916 (GBP) |
Funding ID | ST/F012012/1 |
Organisation | Science and Technologies Facilities Council (STFC) |
Sector | Public |
Country | United Kingdom |
Start | 07/2008 |
End | 07/2013 |
Description | Rayner Rodriguez |
Organisation | Spanish National Research Council (CSIC) |
Country | Spain |
Sector | Public |
PI Contribution | hosting a visit by Dr Rodriguez-Guzman and performing calculations together. |
Collaborator Contribution | by developing a new collaboration amongst theoretical physicists |
Impact | a preprint of a paper has appeared http://arxiv.org/abs/1101.1699 though it is not yet accepted for publication |
Start Year | 2010 |
Description | Shell Model for Laser Spectroscopy |
Organisation | University of Manchester |
Department | School of Physics and Astronomy Manchester |
Country | United Kingdom |
Sector | Academic/University |
PI Contribution | provision of theoretical calculations to compare with their experimental data |
Impact | paper as listed in publications section |
Start Year | 2007 |
Description | I'm a scientist |
Form Of Engagement Activity | A press release, press conference or response to a media enquiry/interview |
Part Of Official Scheme? | Yes |
Primary Audience | Schools |
Results and Impact | Live web chat with school pupils; answering their questions about my research immediate positive feedback from school pupils from years 7-11 |
Year(s) Of Engagement Activity | 2010 |