Upgrade of the LUCID detector for High Luminosity LHC

LUCID-2 has been the ATLAS luminometer for the LHC Run-2 data taking (2015-1018), achieving very good performance (0.8% total uncertainty on luminosity) and a similar is expected for Run-3 (2022-2025). But, due to the harsher conditions, the present LUCID won’t be able to operate in HL-LHC. Several proposals for a new detector were made. To test the proposed designs, several prototypes were installed in ATLAS and are under testing. One of these consists in quartz optic fibers that are used both as a Chereknov radiator and as a mean of transport for light. Fibers are read out by a PMT. The novelty of this detector is the double calibration system that is able to monitor both the ageing of the fiber and the PMT gain. In this contribution the first results obtained with the fiber prototype in LHC Run-3 are presented. The first results obtained by an irradiation session and a beam test to characterize the fibers are also discussed.