Laser spectroscopic determination of new forms of nuclear matter in the trans-lead nuclei.

In the subject of Nuclear Physics there exists several key open questions, these include the limits of nuclear existence, whether new forms of matter are present in loosely bound nuclei and how does the ordering of the quantum system change at these extremes. It is only possible to provide answers to these questions by directly studying exotic nuclei that are unstable with respect particle emission. The discovery of a diffuse halo structure in light nuclei such as 8He, 11Li and 14Be, is one example of nuclear structure that surprised the entire nuclear community. These incredibly systems, with just a few nucleons have a diffuse structure that is comparable in size to some of the heaviest nuclei known in nature such as 238U. With a new technique that offers a vast improvement in sensitivity, this fellowship has the unique opportunity to make measurements in a region of the nuclear chart previously described as 'terra incognito'. Such measurements offer the tantalizing possibility of discovering new structural phenomena and thereby begin to provide answers to the current open questions in Nuclear Physics. This fellowship will unambiguously measure specific nuclear observables, which can be extracted without invoking nuclear models, by studying the orbital atomic electron. Although often quoted as negligible there is a finite interaction between the nucleus and the atomic electrons, which is approximately a hundred million times smaller than the energy spacing of quantum levels within the atom. Such small effects are well within the scope of modern laser technology, which can perform measurements with an unprecedented resolution of one part in a thousand billion! This proposal will accurately measure the change in energy of the outer atomic electron in exotic radioactive isotopes and by doing so extract several key nuclear observables; the magnetic and electric moments, the angular momentum of the nuclear state and the change in the average charge radius of nucleus. These observables provide a wealth of information on the distribution of matter and how the quantum levels are ordered within the nucleus. This proposal will therefore be a significant part of the UK strategy in nuclear physics research providing for the first time, measurements on exotic nuclei where new forms of matter may exist.