Leggi in italiano

The FAIR site in Darmstadt, Germany, Credit: GSI Helmholtzzentrum für Schwerionenforschung GmbH, M. Konradt.

You could call it a LHC for nuclei. What CERN’s Large Hadron Collider does for particles, the Facility for Antiproton and Ion Research (FAIR) will do for heavy ions. By accelerating them and making them collide, it will reproduce the exotic nuclear reactions that take place inside stars. FAIR is under construction at the GSI Helmholtz Centre for Heavy Ion Research in Darmstadt, Germany, and will be fully operational in late 2025. Physicist, Paolo Giubellino, currently on leave from the Italian National Institute for Nuclear Physics, has been the scientific director of GSI and FAIR since 2017, after his term as spokesperson for the ALICE experiment at CERN. We spoke to him about the research programme, why – despite an Italian director and the involvement of several researchers and companies – Italy is not an official member of FAIR, and why next year may be the last opportunity to join in.

What makes FAIR a unique facility for nuclear physics?

It will have the highest intensity ever reached for ion beams, of the order of a billion of ions per second. It is 100 times higher than current facilities, thanks to special superconductive magnets in our 1,100 metre synchrotron ring. Unlike LHC that focuses on high energy collisions in order to study the interactions among elementary particles, we focus on intensity, the number of particles in the flux, to study very rare nuclear processes. FAIR will accelerate any kind of ion, from hydrogen to uranium. Furthermore, a device called Super Fragment Separator will sort the exotic isotopes produced in the interactions, and three storage rings will decelerate them to study processes which occur inside stars and planets at lower energies.

What are the basic questions that scientists will be able to address?

The CBM experiment will study high-density matter, such as that found inside stars and planets. We know a lot about the surface of celestial objects, but very little about their inner structure. The NUSTAR collaboration will run experiments to reproduce the processes that occur during supernova explosions and mergers of neutron stars, from which exotic isotopes are originated. The chemical elements heavier than iron emerge from the decay of these isotopes, and we want to understand how they are formed and their relative abundance on Earth. This would be impossible to perform at lower intensities, because the processes are extremely rare. Finally, the PANDA experiment will create exotic hadrons and study how strong interactions, that bind together quarks and gluons inside them, behave at larger distances.

Paolo Giubellino. Credit: GSI Helmholtzzentrum für Schwerionenforschung GmbH, G. Otto.

FAIR will also carry on applied sciences. Which are the most compelling potential applications?

FAIR will allow the improvement hadron therapy for cancer. The APPA collaboration will explore methods to limit the damage to the healthy tissues, such as flash irradiation, where a curative dose of radiation is delivered in less than a second. A second project will concern the use of radioactive carbon isotopes to simultaneously treat cancer and perform imaging, in order to adjust the beam direction in real time. Moreover, the collaboration will study the effects of space radiation on astronauts and materials in collaboration with the European Space Agency, producing the best simulation of cosmic rays ever.

Italian scientists are involved in all four scientific collaborations, but Italy is not among the consortium members, which include seven European states, Russia and India. Why?

Out of 3,000 researchers from more than 50 countries who participate to FAIR research, 150 belong to Italian institutions. Italian industry has been involved in important components, such as magnets for the Super Fragment Separator manufactured by Asg Superconductors in Genoa, or power supply units provided by OCEM in Bologna. But the agreement to become full members of FAIR was signed in the early 2010s at the beginning of the debt crisis, and this prevented several Southern European countries from joining. In addition, at the time the nuclear physics community in Italy was strongly supporting the development of the SPES facility at the Legnaro National Laboratories, which will tackle similar problems with a different technology.

What would it take for Italy to become member of FAIR, and what benefits could it derive from it?

Member countries are requested to offer in-kind contributions (i.e. products or services provided to the consortium for free) for at least 1% of the construction costs, which amount to nearly €3 billion. The orders already obtained by Italian industries would have been enough. There are still in-kind contributions which Italian industries could offer for a total of almost €30 million, but the agreements on these components will be signed in the next year or so. Being a member would give opportunities for industrial development and to influence the future of the facility. FAIR has several decades of activity ahead and it will remain unsurpassed for a very long time.