C.J. Zilverschoon — 1923-2012

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

Coming from the University of Amsterdam as an applied physicist, he was one of the staff whose engineering competence was particularly appreciated at CERN by some of the research staff coming from smaller home institutions. Arriving in 1954, his obvious place at CERN was the PS project, the construction of the 25 GeV Proton Synchrotron, where he took charge of General Engineering. After my arrival 2 years later one of my first (and repeated) experiences in the barracks where we had our offices up to early 1957 was shouting laughter out of C. A. Ramm’s office, CAR was my Group Leader in charge of PS magnets. Kees (CJZ) and CAR had become close friends.

When the PS was finished, CJZ choose to work on developing future projects and joined the Accelerator Research Division. He thus was an important participant in the fierce competition which continued for several years between two projects: increasing the available collision energy by building a pair of 30 GeV storage rings or by building a 300 GeV synchrotron (now known as the SPS). After tests on a prototype electron storage ring it was decided in 1965 to build a system of Intersecting Storage Rings. CJZ joined the ISR Project while still leading the Committee examining proposals from many Member States for possible alternative locations of the SPS. The ISR began operation in 1971 and was stopped in 1983.

From 1970 to 1975 CJZ was Director of the PS Department, where a new 50 MeV linac and the 800 MeV Booster were added to the PS. He assumed at the same time the charge of Director for Programme and Budget.

Thereafter he returned to Long-term Studies, were he was mostly interested in the Electron-Positron Collider (LEP), which is now replaced in the same tunnel by the Large Hadron Collider (LHC).

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

Even without close contacts, Kees was always appreciated by everybody as a friendly senior colleague combining an enormous 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 to-day.

Günther Plass