Performance of the Tile Calorimeter Demonstrator system for the ATLAS Phase-II Upgrade

The High Luminosity Large Hadron Collider (HL-LHC) will deliver five times the LHC nominal instantaneous luminosity, after a series of upgrades scheduled to take place in the 2025 - 2027 during the long shutdown. The ATLAS Tile Calorimeter (TileCal) will require the complete replacement of the readout electronics in order to accommodate its acquisition system to the increased radiation levels, trigger rates, and high pile-up conditions during the HL-LHC era. The upgraded readout electronics will digitize the PMT signals from every TileCal cell for every bunch crossing and will transmit them directly to the off-detector electronics. In the counting rooms, the off-detector electronics will store the calorimeter signals in pipe lined buffers while transmitting reconstructed trigger objects to the first level of trigger at 40 MHz. The TileCal upgrade project has undergone an extensive research and development program as well as several test beam campaigns. A Demonstrator module has been assembled using the upgraded on-detector electronics for data taking during Run 3. The Demonstrator module is operated and read out using a prototype Tile PreProcessor (TilePPr) which also permits integrating the Demonstrator module into the present ATLAS Tile Data AcQuisition (TDAQ) system. This contribution presents the status and performance of the Demonstrator module in the ATLAS experiment.