Colleagues recall his many contributions and accomplishments.
Franco Bonaudi, who died on 21 December 2008, was one of the first electronic engineers to work for CERN. In July 1952, two years before the organization was formally created, he was sent from Rome by Edoardo Amaldi to Liverpool, to learn about synchrocyclotrons. Speaking only some basic English, he arrived in Liverpool with Frank Krienen, assistant to Cornelis Bakker, the newly appointed team leader for the 600 MeV Synchrocyclotron (SC) that was to be CERN’s first accelerator facility. Bonaudi got on so well with his hosts and his new boss that, as well as perfecting his English and learning about accelerators, he acquired valuable training in dealing with industrial firms, as Krienen had earlier worked in the research laboratories of Philips at Hilversum. Krienen and Bonaudi left Liverpool when the CERN staff started to gather close to the Geneva site where the new European laboratory was to be built. Most of the SC team were housed in barracks at Geneva’s airport, but Bonaudi, with Joop Vermeulen, was soon dispatched to a hut on the Meyrin site to oversee the construction of the accelerator. The staff of the infant CERN numbered around 150 at that time and were of many different nationalities and nearly all strangers to the region. Communicating in poor English, they worked together as family and friends – the first CERN telephone directory contained private numbers. Bonaudi said of that period: “We made real friendships”. At the same time, they rapidly completed their professional task and the first beam circulated in the SC on 1 August 1957.
Meanwhile, a much larger undertaking was progressing well, with the construction of the 24 GeV PS. Before the machine saw its own first beam on 24 November 1959, Bonaudi had become leader of the Apparatus Layout Group and so taken his first steps from machine builder towards experimental support, which was to become his greatest strength. Theo Kröwerath, a charismatic figure who progressed from driving a tank to being responsible for CERN’s Transport Group, still remembers the trips to suppliers that he made with Bonaudi at that time and believes that he owes his professional success to those, like Bonaudi, whose approach epitomized the spirit of the early CERN. This ethos was grounded in a tremendous respect for the work of all members of a team, whether they were engineers, physicists, technicians, mechanics or crane drivers, with – an added speciality of CERN – the more nationalities in a group, the better.
In 1963, with construction of the SLAC 20 GeV linear accelerator just beginning, Bonaudi went to California for a year to help to design the experimental areas. He shared an office with David Coward, who remembers that Bonaudi’s experience proved invaluable. He made significant contributions to designs of radiation shielding, for both personnel and experimental equipment, and to the design of the distribution of utilities throughout the SLAC experimental areas. He also actively participated in the physics meetings that helped to establish the nascent SLAC experimental physics programme. At the same time, Bonaudi made friends for life and helped to initiate a successful series of exchanges of physicists and engineers.
Back at CERN, Bonaudi was asked to design the experimental areas for the Intersecting Storage Rings (ISR), based on the space and facilities indicated by some initial ideas for experiments. Construction began in 1966, with CERN’s Meyrin site extended into France to accommodate the machine. Bonaudi, as head of the ISR General Layout Group, was responsible for building the halls for experiments and the tunnels for the whole machine.
The group included its own civil engineering section and later had sections for both electrical cabling and power distribution. Taking over responsibility for the control and signal cabling – invariably underestimated for physics and machines alike – revealed another insight into Bonaudi’s way of solving problems. When cabling teams fell behind schedule, he would invite all of the members of the group to join him on a cable-pulling weekend. Such was his popularity that it was always a huge success, with everybody knowing that “the boss” would be working harder than anyone, on the worst part of the task. His unspoken motto was: “Let’s get the job done as simply and quietly as possible.”
From the ISR to LEP
With the ISR construction satisfactorily completed and first beams colliding in January 1971, Bonaudi converted his construction team into the ISR Experimental Support Group, which offered extensive assistance to the many and diverse experiments. It is worth noting that, while it was necessary to excavate a few pits to create more space under the collision regions for some of the later, larger experiments, the halls proved to be correctly dimensioned, though some of the built-in flexibility, such as demountable machine piers, was never needed.
Both John Adams and Léon Van Hove, as executive and research directors-general respectively, recognized Bonaudi’s success at the ISR. As a result, he became a much appreciated member of the directorate with responsibility for the entire CERN accelerator complex. His mandate included the period when the SPS was converted into a proton–antiproton collider, following the proposal by Carlo Rubbia. Bonaudi chaired the committee of accelerator experts that defined the final layout of the whole project and chose stochastic cooling, invented by Simon van der Meer at the ISR, to produce the low-emittance, 3.5 GeV beams of antiprotons. This latter choice, together with the decision to accelerate the antiproton beam in the PS before injection into the SPS – an essential point that Bonaudi recognized and finally decided – was the key to the success of the Nobel Prize-winning project.
After completing his three-year term in the directorate, Bonaudi was delighted to be invited to join the UA2 experiment and work hands on with particle detectors, namely the central calorimeter, from testing to data taking. Pierre Darriulat, who was the spokesman of the UA2 experiment, recalls that Bonaudi’s colleagues on UA2 liked him a lot, and respected him highly for his wisdom. On many occasions where a difficult decision had to be made, his advice was taken and followed. In Darriulat’s words: “He visibly enjoyed the exciting research atmosphere and the contacts with younger colleagues, and his relations with the members of the collaboration were of a very close and profound friendship.” Bonaudi’s wisdom was soon required again by CERN for the LEP project. He was invited to join the project management team with responsibility for the experimental areas. The four, deep, underground areas in CERN’s first project to be classified as an Installation Nucléaire de Base by the French government required a new approach to safety throughout the construction and installation phase. Bonaudi took these aspects seriously and the low accident rates during the project show how successful he was.
The director-general of the time, Herwig Schopper, notes that Bonaudi’s responsibilities for the infrastructure of the LEP experiments – which involved getting the complicated detectors and all of the necessary services installed in time – represented a formidable challenge. It was made particularly tricky by the changing time-schedule that arose from difficulties with the LEP tunnelling. “If the experiments were ready to take data at the turn on of the machine, it was in great part thanks to the untiring efforts of Franco,” says Schopper. Both Schopper and Emilio Picasso, the LEP project leader, stress the importance of Bonaudi’s presence on the LEP Management Board. “Franco’s regular contributions at meetings were always appreciated for the competence of his intervention, and we always followed his suggestions,” Picasso recalls. “I also greatly appreciated that, thanks to him and his group, the collaboration with the physics community was smooth and successful.”
Once the LEP beams were successfully circulating in 1989, Bonaudi’s attention returned to particle detectors, this time taking on the task of scientific secretary of the Detector Research and Development Committee, which advised the director-general on the numerous detector R&D projects being launched for the future high-luminosity LHC. While some might see this as a routine task, for Bonaudi it was an opportunity to work with friends and colleagues from the detector community, as he prepared for retirement from CERN in March 1993.
Retirement meant more time to devote to helping people in other ways, and Bonaudi immediately became involved in training and education, in particular in his home city of Turin, where he was appointed a member of the Academy of Science in 1991. He gave lectures on detectors and accelerators at both Turin University and the Politecnico, where he had completed his own studies in 1950. Even before retiring, in 1988 he became an active member of the scientific committee of the Associazione Sviluppo Piemonte (ASP: the Association for the Development of Piedmont), taking care of the relationship between ASP and CERN.
Throughout the 1990s, Bonaudi gave seminars and lectures to complement courses at Turin University on accelerators and detectors. In 1991 he was one of the founding organizers of the successful school for Italian young researchers and doctoral students, Giornate di studio dei Rivelatori. Emilio Chiavassa, professor of physics at Turin, recalls: “Franco was not only a promoter and organizer of the school, but actively participated every year with enthusiasm and competence.” Now in its XIX edition, the school held on 10–13 February was subtitled “Scuola F Bonaudi” in his memory. In addition, he gave many courses on accelerator physics and detectors at the Politecnico, where he was, says Piero Quarati, “a reference point for all the engineering students who went to work at CERN for their laurea or PhD”. Elsewhere, Bonaudi was sought after as a member of several advisory committees, notably at the INFN-Frascati Laboratory.
Andrew Hutton, director of the Accelerator Division at the US Thomas Jefferson Laboratory, who chaired the DAΦNE Machine Advisory Committee, particularly appreciated his experience at the interface between the accelerator builders and the experimenters. “While Franco had the technical understanding of both groups,” says Hutton, “more importantly, he had the personality to be able to bridge the mutual incomprehension between them. Franco always aimed to help everyone see the best way forward and to understand the point of view of the other side, so everyone left his meetings with the sense that they had gained something – a rare talent.” Bonaudi organized a series of meetings between the DAΦNE accelerator builders and the future experimenters, bringing to the Machine Advisory Committee the results of the consensus that he had engineered. “In the committee he was always low key, adding a word here and there to facilitate the discussions,” remembers Hutton. “What I came to realize only later was that he was aware that I had never chaired a committee like this before, and he was steering me away from pitfalls and mistakes without anyone, including me, being aware of it.”
This ability was also appreciated outside Italy. For a number of years Bonaudi was invited ad personam to be a member of more than one advisory committee for the European Southern Observatory (ESO), and he also chaired a working group. Per Olof Lindblad, who was the representative of the ESO Council on another group, recalls that Bonaudi made particularly constructive contributions concerning the roles of a project scientist and the need for a project manager for the Very Large Telescope.
Bonaudi’s concern for others was always evident, whether driving the elderly and needy for a Swiss charitable organization or actively participating in the Middle East Scientific Collaboration (MESC). Eliezer Rabinovici, professor of physics at the Racah Institute of Physics, the Hebrew University, Jerusalem, recalls: “The group of scientists and interested people that gathered under the umbrella of the MESC was very colourful. We prepared together the activities highlighted by the very special meetings in Dahab and Turin.” In particular, the meeting in Turin was the first occasion when the idea of the Synchrotron-light for Experimental Science and Applications in the Middle East – SESAME, the synchrotron radiation laboratory created under the auspices of UNESCO in Jordan – was introduced to a middle-eastern audience.
Franco Bonaudi’s contribution to CERN is obvious and inestimable. He helped to shape the successful, world-renowned research organization that we know today. His influence went far beyond the boundaries of CERN and, no matter where, all of his colleagues remember him as a great friend, the wisest of men, who will be sorely missed. It was a privilege to know and work with him.
