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Julien Fuchs, recipient of the 2018 ERC Advanced Grants for his Genesis project

Julien Fuchs, CNRS research director at the Laboratory for the Use of Intense Lasers was awarded an ERC Advanced Grant to conduct experiments to elucidate the formation of the heaviest atoms in the universe. These laboratory astrophysics experiments rely on the capacities of ultraintense lasers, like the Apollon laser.

The ERC’s Advanced Grants target high-level researchers recognized as leaders in their respective fields for innovative research subjects, such as the project of Julien Fuchs, CNRS researcher director at the Laboratory for the Use of Intense Lasers (LULI - UMR CNRS, École Polytechnique, CEA). The Genesis Project aims at recreating in laboratory the synthesis of the heaviest atoms in the universe.

The Genesis Project

The origin of so-called “superheavy” elements is still poorly understood. Scientist theorize that they formed during violent celestial events (supernovae explosions or the fusion of neutron stars), but no one has yet been able to reproduce the conditions in laboratory to confirm these hypotheses. The aim of Julien Fuchs’s Genesis project is to bring together the conditions of this synthesis in the laboratory using the new generation of ultraintense lasers, in which researchers from École polytechnique have been involved.

In fact, two ambitious programs – the Extreme Light Infrastructure (ELI) on a European scale and the Apollon laser facilities in Paris-Saclay – are expected to deliver intensities much higher than current systems. The principle of synthesis proposed by the researcher relies precisely on these capacities. 

To manufacture superheavy elements, such as uranium, the atomic nuclei must be enriched all at once in order to overcome the “barrier of bismuth,” an element that decays too rapidly to be made any heavier.  The goal in using intense lasers is to create a plasma (a substance made of charged particles, ions, and electrons) that accelerates the protons, and then to use this proton beam to produce neutrons by nuclear reaction. Finally, by bombarding atoms all at once with multiple neutrons, it will be possible to get past the “barrier of bismuth” and produce in the laboratory elements that are usually created in space.

This methodology is based on the expertise that Julien Fuchs developed on laser-created plasmas in the course of his research career, and that has found new applications thanks to Labex Plas@par – a laboratory of excellence that federates the scientific community of the Greater Paris Area to study plasmas. There, Julien Fuchs had the opportunity to work with astrophysicists to clarify phenomena observed in space.

Their work inspired this innovative research project. The support of the ERC for purchasing equipment and the hiring of doctoral students and young researchers will enable him to further our understanding of the conditions of formation of these superheavy atoms and to identify the astronomical sites in space that may have given birth to them.