Laser Facility ELI-Beamline, Czechia
ELI-Beamline in Dolní Břežany, close to Praque in Czechia is one out of three sites of the European laser facility Extreme Light Infrastructure (ELI). ELI is part of the European plan to build a new generation of large research facilities selected by the European Strategy Forum on Research Infrastructures (ESFRI).
ELI, which will initially be based at three specialised and complementary facilities in Czechia, Hungary, and Romania, will be the world’s first international laser research infrastructure project, pursuing unique science and research applications for international users. The project involves 40 research institutions from 13 countries.
At the ELI-Beamline facility an international team is installing the world’s most intense laser systems. Once completed, these lasers will enable ground-breaking research, not only in the fields of physics and material science, but also in biomedical research and laboratory astrophysics. Czechia will become the host country for top-ranking international research, which will attract further investments into advanced technologies with high added value.
Designer of the building is the renowned British architectural firm BFLS (now Bogle Architects). Apart from the laser center, the ELI-Beamline premises includes a multifunctional office building and laboratories. The most important part of the campus is the laser hall, a solid concrete vat the size of a football field, whose walls and ceilings are up to 1.6 meters thick. The laser hall building has two underground and four above-ground floors. The underground part includes the actual laser hall, adjacent machine rooms and other experiment rooms. It consists of a rigid case, measuring 110 x 60 meters. Additional experiment rooms and laboratories are housed on the above-ground floors (80 x 48 meters).
The concrete supplied for the massive structure of the walls and floors was subject to demanding requirements for shielding against ionizing radiation and minimising vibrations. The most suitable concrete type C40/50 was made with cement CEM III/B 32.5 N-LH/SV. The cement was produced by HeidelbergCement’s subsidiary Českomoravský cement at its Mokra cement plant and the concrete mix by TBG Metrostav, a joint venture of HeidelbergCement. Based on the results of a series of tests, four concrete types were produced and applied in various parts of the structure, according to the construction requirements. Prior to the start of concreting, all the types of concrete were tested on a 1:1 model. During the construction phase, the concrete quality was monitored continuously; a total of 1,488 samples were tested.
The unique character of the entire building could be seen even during the construction phase. The foundation plate of the laboratories is 0.7 meters thick; the foundation plate of the laser hall and adjacent spaces is 0.8 meters thick, and it is reinforced up to 1 meter under the columns and walls. The normal wall thickness is 1.2 meters – but in spaces with ionizing radiation, the walls reach a thickness of 1.6 meters. The ceiling above the laser hall is 1.6 meters thick, and the ceilings above most experiment rooms have a cellular design and a thickness of 1.5 meters.
Construction of the Laser Hall has now been completed, and the lasers will be installed at the center by experts. Two of the lasers were developed in Czechia and two in the United States. The laser center should begin full operation in 2018.