Nuclear 'magic numbers' collapse beyond the doubly magic nickel 78

Scientists from the RIKEN Nishina Center for Accelerator-Based Research and collaborators have used the center's heavy ion accelerator, the RI Beam Factory, to demonstrate that nickel-78, a neutron-rich "doubly magic" isotope of nickel with 28 protons and 50 neutrons, still maintains a spherical shape that makes it relatively stable despite the large imbalance in the number of protons and neutrons. They also discovered a surprise—observations from the experiment suggest that nickel-78 may be the lightest nucleus with 50 neutrons to have a magic nature. Lighter isotones—meaning nuclei with the same number of neutrons but different number of protons—would inevitably be deformed, despite having the magic number of neutrons.

* This article was originally published here