Jean Gervaise 1921 -2007
Jean Gervaise, a pioneer of metrology at CERN, passed away on 10 April. A French geodesist, he was behind the creation and development of CERN's metrology group and was a consistently fervent advocate of innovation to meet the increasingly demanding alignment needs of the accelerators and detectors. Under his leadership, metrology at CERN acquired international renown.
In spite of the disruptions caused by the second world war, Jean Gervaise was able to complete an engineering degree at the Ecole nationale des Sciences géographiques in Paris, which led to a first job in the prestigious Geodesy Department of the Institut géographique national (IGN). This 'queen of disciplines', as he called it, is the most scientific and most complex of the branches of cartography, offering opportunities for exciting and varied - sometimes highly adventurous - missions at home and abroad. The rich experience he acquired here helped to form his great professional qualities, as well as his main traits of character as a private individual and public figure. For Jean Gervaise not only had bold and pertinent technical ideas but was a flamboyant and experienced practical man who was not afraid to speak his mind.
Sent to CERN on a temporary mission by the IGN, he arrived with André Decae on 13 December 1954 to design the PS positioning metrology ('alignment', to use the official jargon). The project placed great demands on the tools available at the time and thus required innovative solutions. The mission became a secondment that later resulted in the award of a first CERN contract starting on 1 January 1956. This marked the beginning of an extraordinary career imbued with the enthusiasm and innovative spirit of CERN's pioneers, each of whom were faced with the task of designing, developing and producing everything from scratch in their respective fields.
In charge of what is generally known as the 'Survey Group' (also 'Alignment', 'Metrology and Topometry' and 'Applied Geodesics' over the years), he succeeded in meeting the increasingly challenging needs of successive machines and experiments, acquiring the required new skills, initiating the development of specific methods and instruments (Distinvar, wire and laser offset measuring devices) and achieving technical performances that gained him international recognition in the field. His developments have found applications not only in particle accelerators but in many other scientific, technical and industrial domains.
Jean Gervaise's remarkable innovations and achievements from the very start of his career led to a brilliant PhD from the University of Munich in 1965. Passionate about geology and geomechanics, he looked back with particular fondness on the search for and geotechnical classification of possible sites for the 300 GeV (SPS) machine, which he regarded as one of the great periods of his career. Other highlights include technical and methodological developments for the underground north-finding gyroscopes and his daring decision to base the piloting of the SPS and subsequently LEP tunnelling machines on unusually long distances between reference points issued from the surface, thus generating significant savings. The required precision involved made this seem inconceivable but it proved a great success in both cases. The acquisition of an exceptional distance metre (known as the Terrameter, with a precision of 1 mm per 10 km) gave LEP the world's most precise ever geodetic network. This enabled conclusive checks of the high-precision geodetic use of GPS to be carried out, the results of which were greeted with great excitement at a conference on the first applications of GPS technology for precision positioning held in 1985.
At the same time, Jean Gervaise was a manager with an eye on both CERN's future and that of his colleagues, always concerned for their personal development and to ensure that they enjoyed harmonious relations and were happy in their work. Conscious of the importance of education and communication, he was particularly attentive to the training of young people. This was the start of a tradition that has been continued and even reinforced by his successors, as the group has welcomed more than 250 trainees over its history.
Following his retirement in 1986, he helped to found the CERN Pensioners Association and served a term of office as its chairman. It would be impossible to conclude this tribute without mentioning the man behind the public figure. He was a good and true friend to those who knew him, hospitable and generous, and always ready - together with his wife Madeleine - to welcome you to his home or table; we will not forget the happy times we spent with him nor the warmth of his personality.
Michel Mayoud -
Successor to Jean Gervaise from 1986 to 2005
