This project uses the Modular Neutron Array (MoNA) to study the nuclear properties of very neutron-rich isotopes. The nuclear structure of these isotopes is particularly interesting as much of our current knowledge of atomic nuclei has been built up by studying the naturally occurring isotopes, which have nearly equal numbers of neutrons and protons. The MoNA collaboration will measure the decay energy of several neutron-unbound nuclei. These measurements will help to refine nuclear mass models and to examine the evolution of nuclear structure in these very neutron-rich isotopes, particularly as the last few neutrons become only very weakly bound to the nucleus. We hope to study several such isotopes in the region from beryllium to near oxygen and fluorine, including the unbound oxygen nucleus with an atomic mass of 25 (nine more neutrons than the most common stable isotope, which has an atomic mass of 16).
The Modular Neutron Array was built by undergraduates, and continues to be used in ways that are designed involve students in experimental work and data analysis. The MoNA collaboration is a group of faculty and students from nine colleges and universities that work together to study the structure of nuclei close to or slightly beyond the neutron dripline (where there are no particle stable isotopes with a greater number of neutrons). The experimental work will be carried out at the National Superconducting Cyclotron Laboratory at Michigan State University. The focus of this research is on the structure of the neutron rich oxygen and carbon isotopes. One clear but less tangible result of both of these research activities will be that several undergraduate students will have the opportunity to participate in exciting nuclear research during the earliest years of their scientific careers.
