CRIS-TRAP: a gas-filled linear Paul trap for the CRIS experiment at ISOLDE

Nuclear Physics aims to understand the structure and dynamics of nuclear systems. It is the key to understanding the Universe from the first microseconds of its inception when the quark-gluon plasma prevailed, through its history of star and galaxy formation where nuclear reactions play an essential role both in the generation of energy and the creation of elements. The field also has applications that benefit society in diverse areas, from medicine and security to power production, and a strong impact on other fields of science.

Atomic nuclei are a unique quantal laboratory in which microscopic as well as mesoscopic features, driven by effective two-body and three-body forces, can be studied. They are complex many-body systems, but often display unexpected regularities and simple excitation patterns that arise from underlying shell structure, pairing and collective modes of excitation. Such properties are also exhibited by simpler mesoscopic systems (for example, metallic clusters, quantum dots, and atomic condensates) the understanding of which draws heavily on techniques developed and honed in nuclear physics. A fundamental challenge is to understand nuclear properties ab-initio from the interplay of the strong, weak, and electromagnetic forces between individual nucleons. In recent years, enormous progress has been made with such programmes for light nuclei. For heavier nuclei, shell, cluster and other beyond mean field many-body techniques, based on effective interactions, provide essential frameworks for correlating experimental data, yet still lack the refinement to reliably predict nuclear properties as one moves more than a few nucleons from well-studied stable nuclei.

We plan to make measurements of ground-state and isomer properties using lasers to yield data with which to study the development of nuclear shapes, the evolution of nuclear structure in exotic isotopes important for the s and r nucleosynthetic pathways. Precision laser spectroscopy experiments provide robust observables to test and validate these new theoretical models. This validation work directly supports the next generation of experiments searching for physics beyond the standard model, such as dark matter detection, neutrino oscillation and neutrinoless double beta decay, which all require accurate determination of the associated nuclear matrix elements. It is therefore essential that these nuclear theories are vigorously tested against experimental observables.

A specific aspect of the CRIS method has applications in mass spectrometry. The CRIS technique has the ability to efficiently suppress interference masses that otherwise prevent the detection of the isotope or molecule of interest. In principle it can be used to increase the sensitivity of mass spectrometry techniques such as inductively coupled plasma mass spectrometry (ICP-MS) and isotope-ratio mass spectrometry (IR-MS) by many orders of magnitude. With the level of sensitivity offered by the CRIS technique may represent a disruptive technology in the field of carbon dating. See Pathways to Impact for more details.

Trained manpower at postgraduate and postdoctoral levels is in great demand in nuclear, software and instrumentation industries. Young scientists trained within academic nuclear physics are the only source of independent expertise in areas concerning radioactivity and radiation detection. The importance of this expertise can only increase in the future as the UK moves into its new nuclear build programme. The Nuclear Industrial Strategy recognises the key enablers will be an increase in nuclear R&D and development of nuclear skills. Handling and disposal of nuclear wastes, reactor decommissioning and advanced reactor designs will become even more important issues in society. The research undertaken will also directly inform the teaching of undergraduates at Manchester who will benefit from advanced courses involving examples from topical, current research issues.