Research at GSI – An Introduction
Scientific research has provided an increasingly comprehensive insight into the structure of matter and of the development of the universe. At the same time, the new insights generated many technical developments and applications. The bigger part of the insights attained we owe to experiments at accelerator facilities.
A key instrument for research at GSI is such an accelerator facility. In a combination of linear accelerator and synchrotron, in huge vacuum pipes, charged atomic nuclei, lead by magnetic fields, are accelerated to very high velocities and afterwards shot onto a metal foil. An analysis of the "debris" produced thereby, the new particles created, provides new insights and findings about the structure of the investigated systems and the powers holding them together.
The main focus of the GSI research program is the basic investigation of the field of nuclear physics and atomic physics. In parallel, application-oriented research activities in materials research, plasma physics, biophysics and nuclear medicine were developed. To supply state-of-the-art facilities for science, the accelerator facilities and the experiment facilities are permanently being enhanced and improved.
Nuclear and Particle Physics
In the field of nuclear physical basic research, investigations of nuclear structure are of particular importance. One example for this is the synthesis and discovery of the six heaviest elements of the periodic table of the elements up to element 112. Also the study of the properties of exotic nuclei - nuclei with extreme numbers of protons and neutrons - lead to new insights on the origin of chemical elements in stars and star explosions.
Another large field of work of nuclear physical basic research at GSI is the study of hot and dense nuclear matter. With heavy ion beams, the multiple varieties of nuclear matter, from the "liquid" normal state over the free nucleon gas, to the disintegration of the nuclear components into quark-gluon plasma, can be studied. This field of science also concerns astrophysics because scientists believe that few fractions of seconds after the big bang, the whole matter of the universe existed as quark-gluon plasma. Furthermore, the dramatic course of supernova explosions and the characteristics of the neutron stars created there are mainly determined by the behavior of condensed nuclear matter.
The investigation of properties and processes in the atomic shell are also object of the GSI research program. For example, by experiments with hydrogen-like atoms - atoms with only one shell electron - quantum electrodynamics, generally the most accurate physical theory, is now verified for the highest atomic numbers.
Research in plasma physics goes in completely another direction. By irradiation of a gas target by intense ion beams, very hot and dense plasmas can be created, due to the very effective deposition of energy. These studies are designed to contribute to approach conditions that can be found in stars or in the interior of large planets.
Biophysics and Medical Science
The behavior of cells when irradiated by ions is a topic the scientists of the GSI biophysics group deal with. By the tumor therapy developed at GSI they proved in an impressive way how basic research can lead to an application. From 1997 to 2009, tumor patients were successfully treated with ion beams at GSI. In doing so, tumors in the head were irradiated by accelerated carbon ions, tumors that could not be treated with conventional therapy methods hitherto. In this pilot project, newly developed radiobiological and technical methods are applied. The method is now in clinical routine operation at the Heidelberger Ionenstrahl-Therapiezentrum HIT.
But also the properties of solid bodies can be changed systematically by irradiation with ion beams. This allows innovative technological applications in the field of basic materials, e. g. the production of membranes and the modification of materials.
The Search Goes on...
In spite of the enormous progress made in physics, there are still many problems to be solved concerning the structure of matter and the evolution of the universe. This is why the GSI scientists plan a new accelerator facility, consisting of an accelerator ring encompassing 1100 meter and a complex system of storage rings: the Facility for Antiproton and Ion Research FAIR. At the facility, highly intense and highly energetic ion beams and antiproton beams of best quality will be available for research. The project was approved by the 'Bundesministerium für Bildung und Forschung' (Federal Ministry for Education and Science) and will be implemented in international collaboration.