GSI logoGSI is an accelerator facility for ion beams and secondary pion beams which is unique in Europe. It repeatedly enabled researchers to make new, and sometimes unexpected, discoveries. The high quality of accelerators are complemented by a large number of technically highly advanced experimental facilities.


GSI operates an accelerator complex, which consists of the linear accelerator UNILAC, the heavy-ion synchrotron SIS and the experimental storage-cooler ring ESR. Ions of all elements, from hydrogen to uranium, can be accelerated with energies from the Coulomb barrier up to 2 A. GeV. In addition, radioactive and cooled stable beams with high charge states up to U92+ can be delivered. Moreover, secondary pion beams with momenta from 0.5 to 2.5 GeV/c are available.
The high standards of the accelerators are complemented by a large number of technically highly advanced experimental facilities. In particular in the field of hadron physics, GSI provides the following equipment:

  • the 4π detector FOPI to study the properties of compressed and highly excited nuclear matter. FOPI provides a complete momentum coverage for charged particles emerging from the reaction zone;
  • the High-Acceptance Di-Electron Spectrometer HADES to study the properties of vector mesons in nuclear matter, upgraded in 2009/2010;
  • a secondary beam facility for pion beams in the 0.5 to 2.5 GeV/c momentum range. Besides complementary experiments in the nuclear matter program this opens up  unprecedented possibilities in the field of medium-energy hadron physics. The installation of the pion beam facility was supported by the EC within a TMR-RTD project;
  • a detector test facility offering mixed electron, proton and pion beams to be used e.g. by the CBM and PANDA collaborations;
  • a high-intensity upgrade to gradually increase the beam intensities for all ions up to the SIS space charge limit. For 238U26+ this intensity is 2×1010 ions/burst, while it is 1.4×1011 ions/burst for fully stripped 14N. Intense primary N-beams are mandatory for the secondary pion beam facility.

Within the next years, during the construction of FAIR (Facility for Antiproton and Ion Research) experiments at GSI will continue, though experimental beam time will be gradually reduced until 2017, when first experiments are planned to start at FAIR. With the increase in energy and intensity of ion beams by a factor of 20, beams of protons, antiprotons and unstable nuclei supplied by FAIR in brilliant quality, new challenging research topics can be addressed. Beams supplied by GSI and FAIR offer such a large spectrum for high-energy particle research, that more than 2400 scientists worldwide have already declared their interest in performing experiments at those facilities.


The HadronPhysics3 project is supported by the European Union
under the 7th Framework Capacities Programme in the area of Research Infrastructures (RI).