GSI  >  @Work  >  Research  >  NUSTAR/ENNA  >  NUSTAR/ENNA Divisions  >  SHE-Physik  >  Research

Research

Research at SHIP concentrates on the synthesis and investigation of superheavy nuclei and of very neutron-deficient heavy isotopes.

Nuclear chart
fileadmin/_migrated/pics/NuklidkartenIsotope.jpg
Picture 1: Nuclear chart with the region of known heavy and superheavy nuclei. The nuclei discovered at SHIP are marked with blue frames(Image source: GSI Helmholtzzentrum für Schwerionenforschung)
Nuclear chart

 

Elements with proton numbers Z≥104 are called superheavy elements (SHE). They can only exist because the neutrons and protons are arranged in shells. This gives an additional stability to the nuclei, which prevents their instantaneous fission. For certain neutron and proton numbers a particularly high stability is expected for the respective nuclei which should enhance their half-lives.  This "island of stability" is expected for proton numbers Z=114 or 120-126 and neutron numbers N=184. To reach and explore this island is presently the main goal of SHE research.

Nuclear Spectroscopy

With spectroscopic methods the arrangement and energy levels of the neutrons and protons in the nucleus can be determined.  Especially the structure of nuclei at the limits of stability is essential for the test and further development of nuclear models. At SHIP spectroscopy is performed on heavy and superheavy nuclei with up to 110 protons by detecting alpha particles, gamma rays and conversion electrons which are emitted from excited nuclei.

When the projectile and target nucleus come into nuclear contact during a collision they stick together and form a di-nuclear system. This allows the neutrons and protons to flow from one nucleus to the other, which is regarded as first step of a fusion process by some theoretical models. At SHIP the formation and time development of di-nuclear systems which lead to the formation of superheavy elements can be studied.

The mass of an atomic nucleus reflects its binding energy and, hence, the nuclear forces. Therefore, the measurement of nuclear masses with high accuracy allows for the test of nuclear models, which is especially interesting for nuclei at the limits of stability. High-precision mass measurements on heavy and superheavy nuclei are feasible with the SHIPTrap facility.