In experiments at the GSI Helmholtzzentrum für Schwerionenforschung accelerator facility scientists discovered a total of six new elements.
Chemical elements are produced in stars and in stellar explosions. Ultimately, these elements are the building blocks of all materials that surround us — including every atom of our bodies. However, the universe is also home to a large number of other atoms that do not occur on the Earth.
One of the key tasks of the researchers at GSI is to attempt to create previously unknown elements in the laboratory. For the creation of a new element, scientists use two elements existing on Earth of which the atomic nuclei added together have as many protons as the new element. They try to fuse the nuclei of the two elements together in order to create a new atomic nucleus much larger and heavier than the two original nuclei. For this purpose, scientists accelerate charged atoms – so-called ions – of the one element by means of a 120 m long linear accelerator to extremely high velocities of roughly 30,000 kilometers per second. Subsequently, the accelerated ions are “fired” at a very thin foil of the other element. In a very rare cases, e. g. once a week, the two elements fuse to form a new element.
By means of a very sensitive detector, the new element is being identified. Thereby it is decisive that the new element is not stable. It decays into another, lighter element already after splits of a second. During the decay process, it emits a characteristic alpha particle. This process is repeated several times. The detector can precisely measure these emitted alpha particles and thus clearly identify the new element.
In these experiments scientists at the GSI Helmholtzzentrum discovered the chemical elements with atomic numbers 107 to 112. The highest currently discovered element is 118. It is not clear whether any element can exist beyond that number.