Department of Astronomy & Physics
Exploring Neutron Rich Isotopes in our Universe.
We are proud to announce that Saint Mary’s University Physics Professor Rituparna Kanungo has been awarded an NSERC-DAS award (Discovery Accelerator Supplements) for $120,000 over three years to study the structure of the nucleus of the atom. The DAS award, to quote the NSERC web site, is given to “researchers who have a well-established research program [which is highly rated in terms of originality and innovation] and who show strong potential to become international leaders in their respective area of research.” The award will supplement her five year NSERC Discovery grant of $500,000.
Dr. Kanungo is studying neutron rich nuclei. The conventional picture of the atom we were taught in school still holds true: the atom is made up of a core, or nucleus, of neutrons and protons surrounded by electrons. The protons have a positive charge that in neutral atoms is balanced by the negative charge of the electrons. Neutrons have about the same mass as protons but do not have any electric charge. So what are the neutrons for? This is exactly the kind of question that Dr. Kanungo is trying to answer by studying some of the most exotic, rule-breaking types of nuclei, nuclei that have an unusually high number of neutrons compared to protons. Neutron rich nuclei are unstable and decay quickly to other more conventional or stable nuclei. As a consequence they have to be created in the laboratory. Dr. Kanungo is using the particle accelerator beams at TRIUMF (Canada’s national laboratory located at UBC in Vancouver) to create and study neutron rich nuclei.
As to why Nature needs neutrons, Dr. Kanungo, explains, “A neutron and a proton together create a bound system. Two protons (or two neutrons) together are not bound. Such is the mystery of the strongest force in nature (the nuclear force), a complete understanding of which remains as one of our major goals in nuclear science. Neutrons being uncharged, can be added on to a positively charged nucleus without much effort (since they do not face Coulomb repulsion) to create heavier isotopes. Nature likely has chosen this path to create most of heavy elements around us like gold, platinum, and uranium, in the core of supernovae, which are a natural site of many neutrons. We are working on creating and understanding the behavior of these neutron-rich nuclei that are unknown to us now.”
The number of neutrons and protons in isotopes of the known elements. The half-life is color coded with light blue corresponding to unstable isotopes and dark red corresponding to stable isotopes.