Axon' and the infinitely small

123 Continuing the research into the infinitely small, the CERN, the European Organization for Nuclear Research, has installed a new layer of particle sensors right in the very heart of Atlas on 7th May. This is one of 4 detectors which equip the LHC, the most powerful particle accelerator in the world. No second chance! The challenge was to insert the IBL, a sub detector, closest to the beam pipe where particles collide. Scientists had only a few millimeters to put this instrument in place. Axon’ Cable took up the challenge and equipped the detector with miniature cable assemblies and connectors within a very severe environment. To the last milimetre Just like an onion, the Atlas detector is built up of several layers of specialized detectors. Every layer is dedicated to the detection of particles coming from the interaction of protons at very high energies (up to 14 TeV). It makes it possible either to plot their trajectory or to measure their energy. The closer the beam pipe is to the detector, the higher the density of particles, which requires a very high degree of granularity in the electronic channels. And it is right there, as close to the beam as possible that the sub detector IBL (Insertable B-Layer) has been successfully inserted. The role of Axon’ interconnects is essential: with a 10-meter length, they make the connection between the detector, the supplies and the reader systems which analyse the data. Space saving and radiation The Axon’ cable assemblies are made from rectangular and circular miniature connectors. Very close to the particle beam, circular connectors are subject to very severe constraints: a very limited cabling space and needing to be radiation resistant. The wires linked to the connectors are insulated with Poliax®, an insulating material developed by Axon’ to resist radiation. The other key technical issue is the requirement to use materials with low atomic density in order to limit secondary interactions which could interfere with the efficiency of trajectory reconstitution and more generally with the data analysis. A long-term collaboration Axon’ has been working on the Atlas project for several years. In particular, the company made the cabling of the electromagnetic calorimeter which played a major role in the discovery of Higgs Boson in 2013. As far as the IBL is concerned, the first technical exchange started in 2010 with the interconnects being delivered over a few weeks to the CERN at the end of 2013. In May 2014, Axon’ engineers were requested to intervene on site. Their mission was to inspect the state of the connectors after their installation by the CERN - just before the IBL sub detector was put into service. As the access to the Axon’ connectors is progressively closed off during the assembling and the re-starting of Atlas, the challenge was to guarantee the proper operation of the system up to the next shut-down of the LHC planned for 2018. With the help of software, an analysis of the exact positioning of the contacts was carried out by Axon’. « I would like to thank you for contributing to ensure that the last connecting operations occur in the best possible conditions of security » wrote Mr. Didier Ferrere, in charge of the IBL project with the CERN. « We are all proud of this detector. For your information, the cooling system and the first tests show that the detector works in perfect conditions and is ready for the next qualification steps for operating and data collection at the beginning of 2015 ».

For more information on Axon' and the infinitely small talk to Axon Cable Ltd