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

Publications

10 25 50
 
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 Academic/University
Country United Kingdom
Start 08/2008 
End 07/2013
 
Description Rayner Rodriguez 
Organisation Spanish National Research Council (CSIC)
Country European Union (EU) 
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