The upgrade of the ATLAS Luminosity detector (LUCID) for HL-LHC

Throughout LHC (Large Hadron Collider) Run 2, the LUCID detector, that is located 10 cm from beampipe on both sides of interaction point (17 m z axis), has been reference luminosity detector for ATLAS experiment, providing on-line and off-line measurement with high stability a preliminary uncertainty about 1.7%. For high-luminosity LHC, new equipment more demanding precision requirements beam conditions are expected. The will therefore be completely redesigned, exploiting tried-and-tested technologies. Prototype detectors running technologies have developed installed tested during upcoming 3. These consist based PhotoMultiplier Tubes (PMT), which uses quartz window as Cherenkov medium positioned 30 beampipe, low-rate PMT in shadow one shieldings, fiber bundles used Cherenkov-light emitters transmitters calibrated an innovative hybrid LED radioactive-source system. In these prototypes, behavior Hamamatsu R1635 R7459 PMTs evaluated. this contribution, motivations redesign description upgrade illustrated, well detailed account tests performed including characterization study degradation under irradiation.