Clustering in nuclei

Electromagnetic transitions as a probe of clustering in nuclei

USIAS Fellow: David Jenkins
Post-doc: Daniele Montanari

Nuclear physics is presently undergoing a renaissance with the availability of intense radioactive beams at new facilities such as SPIRAL2 under construction in Caen, Normandy. Allied to this are key developments in detector technology which promises a step change in what is achievable. The atomic nucleus is a complex, many-body system built up from up to several hundred protons and neutrons. The structure of the nucleus and how it behaves in different circumstances may be understood as a complex interplay between the individual, single-particle structure and collective structure where the nucleons act coherently. A further way of describing the nucleus is the so-called alpha cluster model, where nuclear states in some light nuclei are considered as built up from building blocks of alpha particles rather than individual protons and neutrons. The alpha particle is not itself a fundamental particle and comprises two protons and two neutrons bound together; the binding is so strong, however, that the alpha particle may be treated as a fundamental particle.
Clustering in nuclei has traditionally been explored principally via nuclear reaction studies. This project will address some key issues associated with alpha clustering using a new approach based on searching for electromagnetic transitions connecting cluster states. The availability of the PARIS calorimeter, in which the nuclear physics group at IPHC in Strasbourg has played a leading role, promises to revolutionise our ability to study electromagnetic transitions. This calorimeter makes use of the novel scintillator material, lanthanum bromide, which has excellent energy resolution. Experiments are anticipated at IPN Orsay and at the iThemba laboratory in South Africa. This project will be carried out in close collaboration with the cluster group at the IPHC in Strasbourg. The project has the potential to open up new directions in nuclear physics and may have important applications to nuclear astrophysics – the origin of the chemical elements.

10-11 February 2014
Course of the Doctoral College of Physics and Chemical Physics:
Interface of Nuclear Structure and Astrophysics
Enabled by USIAS Fellowship of dr. David Jenkins