The TOTEM T2 GEM detector assembly and quality assurance

The TOTEM experiment at the CERN Large Hadron Collider is dedicated to the measurement of the total proton-proton cross section, elastic scattering and soft diffractive processes over a large kinematic range. TOTEM very forward telescope T2, consisting of 40 triple-GEM detectors with fast trigger capabilities, covers the pseudorapidity range 5.3 < |η| < 6.5. The assembly and commissioning of the T2 telescope is described in detail, with the emphasis on quality assurance procedures for the GEM detectors. A scanning system for the GEM foils, an automated capacitance measurement system of the readout boards and an extensive stability and gain test procedure of the active area of the detectors are discussed.