ALICE Zero Degree Calorimeters. The new readout system in LHC Run 3

The Zero Degree Calorimeters (ZDC) were designed to provide the measurement of the event geometry and luminosity in heavy-ion operation. The readout system was redesigned in order to operate in continuous mode without dead time at 2.5 MHz event rate. The new acquisition chain is based on a commercial 12 bit digitizer with a sampling rate of about 1 GSps, assembled on an FPGA Mezzanine Card. The signals produced by the 26 ZDC channels are digitized, and samples are processed through an FPGA to extract information such as timing, baseline average estimation and luminosity.