During the second Long Shutdown (LS2) of the LHC, ALICE is installing three new detectors and implementing continuous data readout with online reconstruction and data compression. The changes are needed to benefit from the increased luminosity of the LHC during Run 3 and 4. The ALICE interaction rate will increase by two orders of magnitude, reaching 50 kHz for Pb-Pb and up to 1 MHz for pp collisions.
One of the new ALICE detectors is the Fast Interaction Trigger (FIT). Its main functionality includes generating minimum latency interaction triggers (<425 ns), luminosity monitoring with online feedback to the LHC, precision collision time with a resolution better than 40 ps, determination of the centrality and event plane for heavy-ion collisions, and tagging of diffractive and ultra-peripheral events. The FIT detector consists of three subsystems: two fast Cherenkov arrays with 2 cm thick quartz radiators coupled to modified MCP-PMT photosensors (FT0), a large-area scintillator disc (FV0) implementing a novel light collection system, and a Forward Diffractive Detector (FDD). FDD comprises two plastic scintillator arrays with fast wavelength shifting bars, optical fibre bundles, and PMTs. The FDD arrays are located ~20 m at the opposite sides of the interaction point. A brief description of the detector and its functionalities will be given together with the installation and commissioning status.
|Collaboration / Activity||ALICE|