CERN Accelerating science

The ALICE detector is undergoing a major upgrade for Runs 3 and 4 during the Long Shutdown 2. This thesis presents the newly-added Forward Diffractive Detector (FDD) covering forward rapidities. It is made of two layers of plastic scintillators further subdivided into four quadrants. The light from the scintillators is collected at the wavelength-shifting bars located in the sides, which are coupled to a bunch of optical fibres transfering the light to a photomultiplier tube. The main difference of FDD from its predecessor, the AD detector, is the use of much faster materials, the implementation of the laser calibration system and the newly-developed front-end electronics. As FDD covers forward rapidities, it will be useful to tag diffractive processes. It will also help in multiplicity and centrality determination and serve as beam-quality monitor and luminometer. This thesis focuses mainly on the FDD construction and its installation at ALICE.