50 years GSI



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History of GSI – A Laboratory for Everyone

The GSI Helmholtz Center for Heavy Ion Research was founded in 1969 under the name Gesellschaft für Schwerionenforschung mbH (GSI), renamed in 2008. Since the foundation the major research institution has gained international renommee. Ideas like the synthesis of superheavy elements and the tumor therapy with heavy ions that GSI has realized and owes its renown to have existed already 40 years ago. But Germany lacked a laboratory for nuclear physics that bundled the capacities of the scientists and helped them to fulfill their visions. "In the 1960s nuclear physicists conducted their research on their own in their universities. Here in Hessen a strong desire for a central facility existed," says Professor Dr. Rudolf Bock, one of the founding fathers of GSI and prime mover of heavy ion research.

Nuclear scientists of the three Hessian universities in Darmstadt, Frankfurt and Marburg triggered the project in 1966: They founded the "Kernphysikalische Arbeitsgemeinschaft Hessen" (KAH) to further science in the region. Hessen was supposed to be the birthplace of a research facility for heavy ion research in proximity to the universities, open for all scientiest with good ideas. Later the universities in Gießen, Heidelberg and Mainz joined the KAH.

Construction works of GSI buildings at the beginning of the 1970s: In the foreground the experimental halls are being built, in the background facilities for the UNILAC accelerator.
A. Zschau, GSI Helmholtzzentrum für Schwerionenforschung

Milestones of GSI History


Foundation of Gesellschaft für Schwerionenforschung mbH


Participation in the the Arbeitsgemeinschaft der Großforschungseinrichtungen (AGF) (now the Helmholtz Association)


First experiments with linear accelerator UNILAC

1981 until 2010

Discovery of six new chemical elements and their official recognization by IUPAC in the Periodic Table of the Elements: Bohrium, Hassium, Meitnerium, Darmstadtium, Roentgenium, Copernicium


Commissioning of the ring accelerator SIS-18 and the storage ring ESR


First patient treatment with carbon ions at GSI therapy facility


Federal Ministry of Education and Research gives green light for the realization of the new accelerator facility FAIR with international participation


FAIR Start Event – official start of the project, FAIR partner countries sign joint communiqué


Commissioning of the PHELIX laser system


Renaming into GSI Helmholtzzentrum für Schwerionenforschung GmbH (GSI Helmholtz Center for Heavy Ion Research)


Opening of the Heidelberg Ion-Beam Therapy Center (HIT)


Foundation of FAIR GmbH, GSI holds a share of 75 percent

Since the beginning of the 1960s professor Dr. Christoph Schmelzer from the University of Heidelberg worked on a concept of a linear accelerator for heavy ions, UNILAC, for projectiles of all elements up to uranium. "I consider the symbiosis of the Hessian goals for the laboratory and this powerful accelerator a stroke of luck. Together a concept for an accelerator facility was developed in the following years," says Bock.

To finance the project the governmental investors had to be convinced. In 1969 the ministry of research in Bonn and the Hessian ministry of education agreed on the funding, the concept, the instrumentation and the location of the new facility – after a discussion with scientists and consultants that lasted three years.

The date of foundation was December 17, 1969. The construction took five years. The planning of the buildings pursued a new concept to further interdisciplinary teamwork. "We didn't want seperated institutes, no kingdoms, but a variable configuaration to enhance communication by mixing operators and users," muses Bock. Building costs were 180 million DM of which 80% came from the federal government and 20% from the state of Hessen. Hessens premier Georg August Zinn had promised an increased percentage above the usual 10% from a state.

This allowed the construction of GSI in Hessen instead of with the competitor Kernforschungszentrum Karlsruhe. In 1975 the UNILAC accelerated the first heavy ions and the experiments quickly started their operation. GSI scientists acquired knowledge about reaction mechanisms of nuclei, their high spin states, about neutron and proton rich nuclei and about atoms without their electron shell by using new devices and methods. A huge success were the discoveries of the chemical elements 107 to 112. Leading question for the researchers was: Where are the limits of stability in the world of nuclei?

Soon a desire for ion beams with significantly higher energies arose, so called relativistic energies. On the one hand these high energies were essential for a tumor therapy, on the other hand they offered new perspectives for the physics of nuclear matter, its equation of state and possible phase transitions.

With regard to a later GSI upgrade already in 1974 a collaboration with the research facility LBNL in Berkeley, California, was established where GSI scientists conducted similiar experiments at the BEVALAC accelerator. The success of these pioneers convinced GSI at the beginning of the 1980s to build an additional ring accelerator, the heavy ion synchrotron SIS-18. Additionally a fragment separator and the storage ring ESR for heavy ions were constructed - innovations significally nourishing and enhancing GSI's experimental possibilities.

In 1972 scientists of the involved universities meet at the GSI depot to discuss the future experimental program.
GSI Helmholtzzentrum für Schwerionenforschung

In 1997 the combination of UNILAC and SIS-18 allowed the successful treatment of patients with tumors by irradiation with carbon ions. With the fragment seperator hundreds of new nuclei could be produced and analysed. The discovery of three new forms of radioactive decay is just another example for outstanding research results.

To probe quark gluon plasma, a state of nuclear matter under extreme density and temperature, GSI initiated the heavy ion program at the european nuclear research facility CERN. They aided in the construction of a heavy ion injector offering a unique experimental program till this day. GSI played a leading part in the ALICE experiment at the new CERN accelerator LHC from the beginning.

But also in Darmstadt the developments continue: At GSI the accelerator center FAIR is being built in international collaboration. FAIR will deliver beams of antiprotons and ions with so far unparalled intensities. Scientists from all over the world expect new insights into the building blocks of matter and the evolution of the universe, from the big bang till today. About 3,000 scientists from more than 50 countries are already working on the planning and realization of the scientific program and the experiment facilities.

GSI's scientific director Kienle (l.) and former director Schmelzer (r.) start the synchrotron SIS-18 in 1990. In the chart in the lower right corner the signal of the first circulation of the beam through the ring can be seen.
A. Zschau, GSI Helmholtzzentrum für Schwerionenforschung