Distinguished CERN physicist Adolf Minten passed away on 21 March at the age of 88.
After graduating from the University of Bonn, where he worked in the team of Wolfgang Paul on the 500 MeV electron synchrotron, Adolf joined the CERN Track Chamber division in 1962. Working under Charles Peyrou, he set up beamlines for the two-metre bubble chamber and actively participated in its broad physics programme. Another important milestone of his career was his time as a visiting scientist at SLAC from 1966 to 1967, where he took part in the early experiments on hadron electro-production and electron scattering at the new two-mile accelerator.
Adolf returned to CERN at a time of decisive developments in accelerator and detector technologies. In parallel to his continued participation in bubble-chamber experiments, he became interested in the physics programme of the Intersecting Storage Rings, the world’s first proton–proton collider, which started operation in 1971. To cope with the high interaction rates expected at this new machine, the development of track detectors focused on the multi-wire proportional chamber (MWPC) developed by Georges Charpak. One of the designs was a large multi-purpose spectrometer called the split-field magnet (SFM). At that time, a large-scale application of the revolutionary MWPC technology, hitherto available only in single-wire devices or small-surface detectors, presented a formidable challenge. In 1969, Adolf became responsible for the construction of the SFM facility, which covered the full solid angle with an unprecedented 300 m2 detector surface, and 70,000 wires and electronics channels. Major detector, electronics and software developments were needed to bring this project into operation in 1974.
In 1975, to prepare for the next generation of experiments at the new SPS machine, the CERN management proposed the creation of a new Experimental Facilities (EF) division. Adolf was elected to lead the new EF division, a position that required a combination of strong scientific and technical authority, and in which he commanded the unreserved respect of his collaborators. Following support provided to the major facilities for the SPS fixed-target programme, such as BEBC, the Omega spectrometer and the neutrino, muon and other experiments, his new division soon became involved in the successful experiments at the SPS proton–antiproton collider.
In 1984 Adolf stepped down from his position as EF division leader and joined the ALEPH experiment at LEP. The LEP experiments were a quantum leap in size and complexity when compared to previous experiments, and demanded new organisational structures. As head of the ALEPH steering committee, Adolf was instrumental in setting up an organisation whose role he compared to an “orchestra, where it is not sufficient that all the instruments be properly tuned, they must also harmonise”. However, his true role of an “elder statesman” went far beyond organisational responsibilities; equally important were his human qualities, which were remarkable indeed and for which he was respected by both young and old.
Adolf maintained a constant interest in DESY, where he was highly appreciated. In 1981 Bjorn Wiik’s study group had finished the HERA design report, and DESY set up an international evaluation committee to analyse it in detail. Adolf was invited to chair this committee. Its positive recommendation was a significant step towards the approval of the HERA project. He chaired the DESY scientific council from 1987 until 1990, during the main construction phase of the storage rings and the H1 and ZEUS multi-purpose detectors.
Adolf retired from CERN in 1996. We remember him as a supremely well-organised scientist of deep and incisive intelligence, unafraid to challenge and question preconceived ideas, and always inspiring others to do the same. At the same time, he was a modest person who cared profoundly for all the people around him, and their families.