Exploring The Changing Shell Structure Of Nuclei

Lead Research Organisation: University of Manchester
Department Name: Physics and Astronomy

Abstract

Most of the mass of the Universe that we can see around us is made up of atomic nuclei, the dense cores of atoms which are only about a million millionth of a centimetre in radius. They contain up to several hundred protons and neutrons (collectively called nucleons) held together by strong nuclear forces and influenced by the electrostatic forces between the positively charged protons. The particular ratios of protons-to-neutrons in the stable nuclei we find in nature are determined by a subtle balance between these forces. Most of the characteristic properties of a nucleus are determined by the way nucleons move inside. This is somewhat similar to atomic physics where the electrons in an atom orbit around its centre. Certain atoms, Nobel gases, are more chemically stable than others. This is related to so-called shell gaps in the energy sequence of the electron orbits which makes these atoms more difficult to excite. Similar quantum mechanical effects come into play in nuclei, where nucleons orbit around the centre of the nucleus. The resulting shell structure is very different as nuclei and atoms are bound by different forces. The nucleon numbers related to shell gaps are known as magic numbers. The corresponding magic and doubly magic nuclei, the latter having magic numbers of protons AND neutrons, have properties associated with enhanced stability, they are harder to excite and react, have long lifetimes and spherical shape. It is easy to study magic numbers in stable nuclei as they already exist in Nature and do not need to be manufactured. These numbers, 2, 8, 20, 28, 50, 82.... are well understood and are related to the specific ways in which a nucleon interacts with the others in the nucleus. Practically all nuclear properties, such as shape, the modes of excitation, the spin, magnetic characteristics and so on, depend on the underlying nucleon orbits. Orbitals and magic numbers are therefore fundamental to understanding the way nuclei behave and how they
 
Description Developed an understanding of collectivity and single-particle structure in sd and fp-shell nuclei. Furthered understanding of matrix elements for double beta decay.
Exploitation Route Input into fundamental science.
Sectors Education,Other

 
Description Contributed to various outreach activities.
First Year Of Impact 2009
Sector Education,Culture, Heritage, Museums and Collections,Other
Impact Types Cultural

 
Description STFC Buclear Physics Grants Round 2007
Amount £1,579,024 (GBP)
Organisation Science and Technologies Facilities Council (STFC) 
Sector Academic/University
Country United Kingdom
Start 08/2008 
End 07/2011
 
Description Argonne National Laboratory 
Organisation Argonne National Laboratory
Department Physics Division
Country United States 
Sector Public 
PI Contribution Intellectual input, performing experiments, data analysis, writing publications
Collaborator Contribution Facility provision and intellectual input
Impact Publications.
 
Description Legnaro National Laboratory 
Organisation National Institute for Nuclear Physics
Department Legnaro National Laboratories
Country Italy 
Sector Public 
PI Contribution Intellectual input, performing experiments, data analysis, writing publications.
Collaborator Contribution Facility provision, intellectual input.
Impact Publications
 
Description Michigan State University 
Organisation Michigan State University
Department National Superconducting Cyclotron Laboratory
Country United States 
Sector Academic/University 
PI Contribution Intellectual input, performing experiments, assisting writing publications.
Collaborator Contribution Facility provision, intellectual input
Impact Publications
 
Description STFC Daresbury 
Organisation Daresbury Laboratory
Department Nuclear Physics Support Group
Country United Kingdom 
Sector Academic/University 
PI Contribution Detector development
Collaborator Contribution Joint grant application, electronics and daq, target manufacture.
Impact Publications. Equipment production.
 
Description UWS 
Organisation University of the West of Scotland
Department School of Physics
Country United Kingdom 
Sector Academic/University 
PI Contribution Performing experiments, intellectual input, writing publications.
Collaborator Contribution Intellectual input, publications.
Impact Publications
 
Description Yale University 
Organisation Yale University
Department Wright Nuclear Structure Laboratory
Country United States 
Sector Academic/University 
PI Contribution Intellectual input, performing experiments, data analysis, writing publications.
Collaborator Contribution Facility provision, intellectual input
Impact Publications
 
Description Rutherford Exhibition at Museum of Science and Industry 
Form Of Engagement Activity Participation in an activity, workshop or similar
Part Of Official Scheme? No
Type Of Presentation Workshop Facilitator
Geographic Reach National
Primary Audience Public/other audiences
Results and Impact Three month exhibition Aug to Oct 2011 of nuclear physics past and present to celebrate the Rutherford Centennial. Estimated visitors 200,000.

Manchester played advisory and facilitator role.

Media coverage.
Year(s) Of Engagement Activity 2011
 
Description Variety of activities as Schools Liaison Officer 
Form Of Engagement Activity Participation in an open day or visit at my research institution
Part Of Official Scheme? No
Primary Audience Schools_students
Results and Impact The PI of the grant was the Schools and Colleges Liaison Officer for Physics and Astronomy. The research outputs of the grant have contributed to talks given as part of the responsibilities this post, to local schools and colleges, at University Open Days held three times a year, and at many one-off events.

Many.
Year(s) Of Engagement Activity 2006,2007,2008,2009,2010