C.J. “Kees” Zilverschoon (1923 - 2012)

C.J. was one of the first staff to join CERN, in May 1954 – when there was no laboratory and only the beginnings of an organization, which was formally founded in September 1954. Most people coming to CERN at that time left a well-established position at home, choosing (as J. B. Adams said in an interview) an ‘adventure against job safety’.


C.J. Zilverschoon in the PS Control Room, 1960. See the full version of the image (with A. Schoch and K. Johnsen) here.

Coming from the University of Amsterdam as an applied physicist, where he had worked on isotope separators, his obvious place at CERN was with the construction project of the 25 GeV Proton Synchrotron. There, he took charge of general engineering and, later, installation and the setting up an operations group. He collaborated closely with C.A. Ramm and G.L. Munday, who were in charge of the PS magnet and the vacuum system, respectively.

When the PS was finished, C.J. chose to work on developing future projects and joined the Accelerator Research Division. He was thus one of the leading figures preparing the design and cost estimate of the next large projects of CERN: the Intersecting Storage Rings (ISR) and the 300 GeV synchrotron (now SPS). There was fierce competition between the two projects for several years: whether to increase the available collision energy by building a pair of 30 GeV storage rings (ISR) or by building a 300 GeV synchrotron (now SPS).

After the Council decision in 1965 in favour of the ISR, C.J. joined it as deputy project leader while still leading, for many years, the group examining proposals from many Member States for possible alternative locations of the SPS.

While the ISR installation was finalized and commissioning started in 1970, C.J. became Director of the PS Department, where a new 50 MeV LINAC and the 800 MeV Booster were added to the PS. At the same time, he assumed the charge of Director for Programme and Budget until 1975. After this, he returned to Long-term Studies, where he was co-leader of the study of the Electron-Positron Collider (LEP), later replaced by the LHC.

He was a member of the ISR Division till 1982 and of the LEP Division till 1988, when he reached retirement age. During these years – and for a few more years during his retirement – he was Chairman of Council’s Committee in charge of the reform of the CERN Pension Fund.

Everyone appreciated C.J. as a very frank, friendly and unassuming senior colleague combining cheerfulness with a very natural authority. For more than thirty years, he was one of the leading personalities who formed CERN to become the laboratory of worldwide radiance it is today.

His colleagues and friends