Caratterizzazione delle camere a GEM per l'esperimento TOTEM al Large Hadron Collider

In this thesis a triple GEM prototype has been characterised by using a 9 KeV X-Ray source. This type of technology will be also used by the TOTEM experiment for the realisation of the T2 detector, placed at about 14 m from the IP, with a pseudorapidity acceptance in the range 5.3<|eta|<6.5. The measurements performed in this work are therefore relevant for an optimal design of the future TOTEM detectors, that have to cope with the harsh experimental conditions of the LHC. After a detailed description of the working principles of the GEM plane, the experimental measurements performed on a triple GEM prototype at the Gas Detectors Development laboratory at CERN are presented. In particular a systematic study on the dependence of the Ion Feedback from the electric fields which characterise the GEM chamber has been reported.