Robert Aymar, CERN Director General from January 2004 to December 2008, passed away on 23 September at the age of 88. An inspirational leader in big-science projects for several decades, including the International Thermonuclear Experimental Reactor (ITER), his term of office at CERN was marked by the completion of construction and the first commissioning of the Large Hadron Collider (LHC). His experience of complex industrial projects proved to be crucial, as the CERN teams had to overcome numerous challenges linked to the LHC’s innovative technologies and their industrial production.
Robert Aymar was educated at Ecole Polytechnique in Paris. He started his career in plasma physics at Commissariat à l’Energie Atomique (CEA), since renamed Commissariat à l’Energie Atomique et aux Energies Alternatives, at the time when thermonuclear fusion was declassified and research started on its application to energy production. After being involved in several studies at CEA, Aymar contributed to the design of the Joint European Torus, the European tokamak project based on conventional magnet technology, built in Culham, UK in the late 1970s. In the same period, CEA was considering a compact tokamak project based on superconducting magnet technology, for which Aymar decided to use pressurised superfluid helium cooling — a technology then recently developed by Gérard Claudet and his team at CEA Grenoble. Aymar was naturally appointed head of the TORE SUPRA tokamak project, built at CEA Cadarache from 1977 to 1988. The successful project served inter alia as an industrial-size demonstrator of superfluid helium cryogenics, which became a key technology of the LHC.
Robert Aymar set out to bring together the physics of the infinitely large and the infinitely small
As head of the Département des Sciences de la Matière at CEA from 1990 to 1994, Robert Aymar set out to bring together the physics of the infinitely large and the infinitely small, as well as the associated instrumentation, in a department that has now become the Institut de Recherche sur les Lois Fondamentales de l’Univers. In that position, he actively supported CEA-CERN collaboration agreements on R&D for the LHC and served on many national and international committees. In 1993 he chaired the LHC external review committee, whose recommendation proved decisive in the project’s approval. From 1994 to 2003, he led the ITER engineering design activities under the auspices of the International Atomic Energy Agency, establishing the basic design and validity of the project that would be approved for construction in 2006. In 2001, the CERN Council called on his expertise once again by entrusting him to chair the external review committee for CERN’s activities.
When Robert Aymar took over as Director General of CERN in 2004, the construction of the LHC was well under way. But there were many industrial and financial challenges, and a few production crises still to overcome. During his tenure, which saw the ramp-up, series production and installation of major components, the machine was completed and the first beams circulated. That first start-up in 2008 was followed by a major technical problem that led to a shutdown lasting several months. But the LHC had demonstrated that it could run, and in 2009 the machine was successfully restarted. Robert Aymar’s term of office also saw a simplification of CERN’s structure and procedures, aimed at making the laboratory more efficient. He also set about reducing costs and secured additional funding to complete the construction and optimise the operation of the LHC. After retirement, he remained active as scientific advisor to the head of the CEA, occasionally visiting CERN and the ITER construction site in Cadarache.
Robert Aymar was a dedicated and demanding leader, with a strong drive and search for pragmatic solutions in the activities he undertook or supervised. CERN and the LHC project own much to his efforts. He was also a man of culture with a marked interest in history. It was a privilege to serve under his direction.
