Nuclear physicists at the GANIL laboratory in France have created nickel-48 nuclei - the last of the so-called "doubly magic" nuclei - for the first time. The discovery will shed new light on theories of nuclear structure. A nickel-48 nucleus contains a magic number of neutrons (20) and a magic number of protons (28). Magic-number nuclei are expected to be very stable, but some theorists had predicted that nickel-48 would be unstable because it contains 11 fewer neutrons than the most common isotope of nickel.
The name magic number comes from the shell model of the nucleus. The combined quantum mechanical effects of protons and neutrons in the nucleus can create energy shells similar to the electron energy levels found in atoms. The number of protons or neutrons required to fill each shell is called a magic number. The GANIL team detected two nickel-48 nuclei among the debris of collisions between a beam of nickel-58 ions and a target containing various nickel isotopes.
