Ageing study and reference measurements of Gas Electron Multiplier Detectors for the Compact Muon Solenoid experiment at CERN

After the Higgs boson discovery in 2012, high energy physicists are designing experiments that will allow them to discover new particles in order to better understand how subatomic particles behave and to better understand what happened moments after the Big Bang.It might seem a contradiction, but to study the smallest particles known to humankind, it is needed to build gigantic machines that even have to cross country borders.At CERN there is the largest particle accelerator in the world, and it is being upgraded to operate at even higher energies (up to 14 TeV). To do this a major update in all the technology surrounding this detector must be made. Especially on the 4 experiments which are found in the collision points of the Large Hadron Collider Beams.One of these experiments is the Compact Muon Solenoid, which needs a new muon tracker and trigger system to be able to cope with the new demands these high energy collision need.Gas electron multiplier (GEM) detectors have been around for a while, and it was decided that it would be this technology that would be used to create the new muon upgrade for CMS.Nevertheless this type of detector needs to prove that it is capable to sustain long term operations and that it will not age. To demonstrate this a series of tests have been made. The detector and some of the materials have been tested under several circumstances. With the exception of the rate capability tests that have not been conclusive, the rest of the tests show a good performance of the GEM detectors.When performing the charging up test, the aged detector behaved in the complete opposite way to the non-age detector. Both aged and non-aged showed very similar gain curves and very low discharge probability. It has been possible to find materials for the detector that do not outgas and it has also been proven that the detector can accumulate charges similar to those of CMS without losing gain.Validerat; 20140922 (global_studentproject_submitter