The Phase-II upgrade projects of ATLAS Tile Calorimeter for the High-Luminosity era

Abstract In preparation for the High-Luminosity phase of the LHC, expected to begin in 2030 and delivering a factor of 5 to 7.5 larger the nominal instantaneous luminosity, a comprehensive upgrade of the Tile Calorimeter is underway. Scheduled for implementation during the Long Shutdown from 2026 to 2030, the upgrade involves a complete replacement of both on- and off-detector electronics, along with the replacement of the photomultiplier tubes reading the most exposed detector parts. This upgrade has encompassed extensive research and development efforts, including detailed test beam studies and the construction of a special module that has been taking data with ATLAS through Run 3. The ongoing progress in the development of both the on- and off-detector systems, the latest results obtained from test-beam campaigns conducted with the electronics prototypes, as well as the findings from the module operating within ATLAS will be discussed.