Examining the Shape of Proton Emitting Nuclei

What is the shape of the nucleus in the moments before it emits a proton? How does the shape of the nucleus change when the proton becomes unbound? This project aims to perform the first laser spectroscopy studies on proton-emitting nuclei, in order to measure the shape and other nuclear properties of these exotic species.

At the edges of the nuclear landscape, a rare form of radioactive decay occurs where the nucleus emits a proton. Studying proton-emitting nuclei with laser spectroscopy provides an opportunity to measure their nuclear properties and understand the behaviour of nuclei right at the limits of nuclear existence.

Laser spectroscopy measures the hyperfine structure of atoms, an atomic fingerprint that allows nuclear properties (e.g. spin, electromagnetic moments and charge radii) to be measured in a nuclear-model-independent way. For example, the charge radius tells us about the proton distribution in the nucleus i.e. its shape. By measuring nuclei across the proton-drip line (beyond which proton decay occurs), we can understand the effect of the proton on the nucleus before it is emitted and gain a unique insight into how this single proton can influence the behaviour of the whole nucleus.

This project will be carried out at the ISOLDE facility (CERN, Switzerland) and the newly-built FRIB facility (Michigan State Univeristy, USA). It will use state-of-the-art laser spectroscopy techniques, such as Collinear Resonance Ionization Spectroscopy (CRIS) and the newly-developed PI-LIST setup, to measure the properties of proton-rich nuclei. There is a Ph.D. studentship available in the areas of laser spectroscopy and decay spectroscopy.