Italians win a technological bet with the international CMS experiment at CERN in Geneva
The last 800 of more than thirty thousand crystals of an extremely sophisticated technology are on their way from the INFN/ENEA Laboratory at the ENEA Casaccia Centre (Rome) towards the European laboratory for particle physics at CERN in Geneva. On March 28th, on the occasion of the last transport to CERN, a closing ceremony will be held at the Casaccia Research Centre, to the presence of the highest authorities of the Entities and of Management of the CMS experiment at CERN.
The event is a great Italian endeavour in science and technology that will allow the new particle accelerator in Geneva, the Large Hadron Collider (LHC), to search for the traces of the “Sacred Graal” of particles, the very “Higgs boson” around which a true scientific competition has developed between Europeans and Americans.
The instrument designed by the INFN and ENEA researchers is called an electromagnetic calorimeter with scintillator tiles and it will be installed in the CMS (Compact Muon Solenoid), experiment which has essentially three duties:
1) to find the Higgs boson, the particle that gives their mass to all the other particles;
2) to study the asymmetry between matter and antimatter that could explain why we live in a universe where all we know is made of matter rather than of antimatter;
3) to seek confirmation of the super-symmetry, one of the theories developed by physicists to solve some of the problems left open by the Standard Model, used by scientists to describe the universe.
The CMS experiment is carried out by a consortium of 55 International Institutes.
The construction of the calorimeter saw the fruitful collaboration of high energy and matter structure physicists pertaining to two of the most important Research Institutes in Italy, the INFN and the ENEA. This collaboration began in 1994 with the study and the development of the innovative lead tungstate crystals. This research project enjoyed strong contributions from ENEA physicists precisely in this domain. In 1997, on conclusion of the research and development phase on the single components of the detector, the two Organisations signed a Working Agreement to institute a Laboratory for the assembly of the calorimeter at the Casaccia. This Laboratory hosts physicists and technicians employed by both Organisations and it is equipped with highly technological scientific devices developed by the INFN. This centre is one of the two in the world where the pieces of the detector are assembled; the other is at CERN.
The 30600 mono-crystals, each of which is 23 centimetres long, have been characterized (that is to say, all their physical properties were measured), instrumented (meaning equipped so they will be able to extract the light they emit when the particles go through them) and set up into alveolar (trapeze shaped) structures. As soon as they were built and mounted onto the modules, the crystals were tied to structures equipped with shock absorbers and they were periodically transported to CERN in Geneva for the final positioning of the detector.