Strip Scintillator Array with ultra-FAst timing for Rare Isotope study (SAFARI)

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Nuclei, the core of all visible matter, embody the beauty of nature's strong force binding the building blocks, protons and into a wide variety of complex many body systems. Most of the long--lived nuclei occurring naturally on earth have a nearly balanced ratio of neutrons to protons. Rare isotopes with a large neutron to proton asymmetry are created in some of nature's most exotic environments that are rich in neutrons, such as neutron stars and supernovae, or rich in protons, such a accretion disks on the surface of a neutron star. These neutron--rich or proton--rich isotopes therefore, open before us a wealth of new knowledge on the fundamentals of how nature organizes such systems and their role in creation of majority of the heavy elements around us. Signature of such element synthesis was recently seen in one of nature's most cataclysmic events, in the merger of two neutron stars. This proposal aims to develop ultra-fast-timing plastic scintillator arrays that are necessary to identify the rare isotopes produced in our laboratories. Their production takes place with nuclear reactions, such as fragmentation or fission in a few specialized accelerator facilities in the world among which the facility at GSI in Germany provides highest energy beams of the rare isotopes. Using the relativistic rare isotope beams we aim to unravel how the neutrons are distributed in such np asymmetric conditions. This provides guidance to characterize the behavior of neutron--rich environments of our Universe. This also brings new information on the nuclear (strong) force and how that governs the arrangement, i.e. shell structure, and properties of the rare isotopes. The properties of these isotopes determine how their reactions and decays drive the creation of most of the heavy elements in nature.