by C.W Fabjan . Published: 20 March 2013

It started in the CERN cafeteria in December 2000 shortly before Christmas, where I ran into my friend and former colleague, Lodovico Riccati. This gentleman, well known for his aristocratic reserved demeanour, was visibly in a hurry, when he asked me: Would you like to become the Alice Technical Coordinator? Let me think about it, was my equally short reply.

The Christmas break gave me ample time to think; my involvement in the ATLAS Muon spectrometer was at a turning point, with R&D terminated and the production of the various detector systems for the muon detection in full swing. Having made a switch in my professional focus about every ten years, this was one more reason to seriously contemplate this challenge. Attending the ALICE collaboration meeting in January 2001, I became convinced that there was enough work for the Technical Coordinator (TC). A few other circumstances helped to shape my decision: Wolfgang Klempt, TC at the time, wanted to devote himself fully to the construction of the TPC and to leading his group. Lars Leistam, another key person, received me warmly. Discussing a possible collaboration we quickly recognized a wonderful level of complementarity in our respective talents (?) and interests. A small team of ‘Technical Coordination’ would be needed. It took some arm twisting to convince Hans Taureg to come on board; I also insisted on the need for a Project Engineer, to which ALICE and PH-management agreed. After discussions with Jürgen Schukraft, Peter Jenni of ATLAS and the PH-Department Head, G. Goggi, the way was cleared. Lodovico, then chair of the ALICE Collaboration board, ensured that my ‘hearing’ at the February CB went smoothly, starting eight exciting years.



Prof. Chris Fabjan inside the ALICE experimement cavern.


Lars was the ‘Master at Point 2’, having managed the L3 experiment, and having been instrumental, together with Jürgen, in the transfer of the unique L3 magnet to Alice. What a legacy! Lars was (fortunately) somewhat infected by a lavish working style, now history: whenever Lars took responsibility for an activity, we were sure, it would be done excellently, albeit not inexpensively…It was therefore natural (thank God, Lars did not insist on a career switch...) that he would bring his knowledge, competence and talents to taking responsibility of all issues related to Point 2 (P2), in particular the integration, infrastructure and assembly. At that time Lars already looked back at a very distinguished career, but he became a CERN-wide notoriety, when he insisted, against all CERN policies, that ALICE should get a machine shop at P2, to the envy of the two heavyweights, ATLAS and CMS. As it turned out, this was essential to putting Alice on the ‘real plane’. He got his workshop but without workers. His next stroke of a genius: while Jürgen was courting potential Chinese collaborators with the promise of the Quark-Gluon Soup, Lars settled the bondage by convincing them that nothing would be more important to Alice then a team of Chinese craftsmen. Our Chinese colleagues agreed with the added bonus of nominating a charming and resolute lady engineer to lead the team. Very well done, Lars, indeed (and inexpensively, for a change). This team was incredibly effective and result-oriented, frequently placing work ahead of safety concerns. For Lars and me safety was of course of upmost importance, and we had to work quite hard to instil this ‘Cultural Revolution’. We managed without major incidents, also due to the pragmatic interventions of the ever-present crane driver, Robert Porret. He was one of these very special persons, whose home was CERN and whose omnipresence and care for the experiment was legendary. The culture of our Chinese team was visible in many ways. Most notable were their Chinese New Year celebrations, to which the colleagues stationed at P2 were invited (I suppose my invitation was ex-officio). Asia would become ever more present: we hosted a team from Pakistan and had surveyors from India.



To celebrate the CERN 50th anniversary and to emphasize the close ties between the community of Saint-Genis-Pouilly, CERN and the ALICE Collaboration, Hubert Bertrand, Mayor of Saint-Genis-Pouilly and Christian Fabjan, Technical Coordinator of the ALICE Experiment, planted a tree on Saturday 16 October 2004 in front of the Jean Monet Culture Center.


Not only did Alice have the best workshop at its experimental site, we also had… the best Barbeque Infrastructure, mostly thanks to our technician and polytalent – he moonlights as an accomplished artist – Didier (Anstett). There I take some credit, having allocated some modest resources for a continuous upgrade of the BBQ facilities. Our annual collaboration summer parties with several suckling pigs roasting in our High-Tec outdoor facility belong to very fond memories.

While Lars was masterminding the ‘House of Alice’ at P2, one of my prime responsibilities was to make sure that the ‘furniture’, the myriad of detectors needed to make ALICE functional would be built to specifications. One tool was the so called ‘Production Readiness Review’ (PRR), of which Hans and I together with our Project Engineer, Diego Perini, took charge of. These reviews were held at the respective home institutions. It provided us with the scientifically and socially very important opportunity to strengthen the all-important local presence of Alice. These were also wonderful occasions to meet the members of the Institute and to create a link of respect and friendship. It was an outstanding team-building tool. We loved it.

On these occasions I discovered India and became very fond of it. We used the visit to our colleagues in Kolkata to always add a few days of tourism, expertly prepared by our local hosts. I have to confess that we were good in finding reasons to schedule a rather large number of PRRs in India, which our hosts endured with grace and elegance, always making us feel welcome. Wonderful memories…

Italy was, understandably, another prime PRR-destination. At one major institute, home of Europe’s oldest university, PRRs were considered not really necessary, but dedicated working meetings were thought very useful. These were productive working sessions, frequently accompanied by considerable media attention and always by exquisite Italian hospitality.

Of course, we had some close calls. I mention two, indicative of the very good collaborative spirit.

One was associated with the ‘Space frame’. This device is a gigantic support structure (see the photo below) for all of the central detectors. Our imaginative Project Engineer, under pressure by the collaboration to design an essentially massless support structure, developed a concept of an extremely light structure, which would assume its perfect shape, only with all the detectors installed. Although manufacturing tolerances were carefully evaluated and respected, it turned out that over the full length of the structure (8 m) tolerances could conspire to make the installation of the detectors difficult, if not impossible. The problem was particularly acute for the Transition Radiation Detector (TRD). We concluded that we had a problem, which we had to confess to the Project Leader, Johanna Stachel. Frankly, I was a bit scared. Johanna has a way of speaking charmingly and softly, yet I have never seen her losing an argument. The TC team made its ‘Canossa Trip’ to Heidelberg…we explained the issue…several hours later with lots of discussion (and a bit of luck) an imaginative and acceptable solution emerged. We went back relieved and grateful for this constructive attitude.



The famous space frame during installation: Too large to pass the doors of the Alice hall, it had to be lifted through the roof. A pleased Diego Perini is taking time out for a photo session


The closest call occurred during the final installation. It required a complexly orchestrated ‘ballet’ of movements involving the displacement of the 80 ton loaded space frame over the most delicate beryllium vacuum chamber with sub-millimetre tolerances. Werner Riegler was the ‘chef d’orchestre’. With great foresight he had installed an elaborate system of position and tension monitors to control the stress on the vacuum chamber within the specifications set by the LHC Vacuum Group. Halfway through the installation the strain gauges on the vacuum chamber indicated values close to maximum allowed stress. Red light! Stop! Thinking, discussing, measuring…Werner finally concluded that – impossible to happen in the view of the experts- a spring-loaded support of the vacuum chamber was blocked…The Vacuum Team managed to unblock the support and the installation was successfully finished.

I was grateful to the Alice management to support my contract extension beyond the fateful age of 65 to help bring ALICE to working functionality. The farewell party was most memorable: to the collaboration I am grateful for 8 marvellous years spent in its company and to the artist-in-residence, Didier, for a remarkable piece of sculpture as a farewell present.

Many happy returns and a most successful continuation, dear ALICE!