The Phase-2 CMS BRIL system for precision luminometry

The CMS Beam Radiation, Instrumentation and Luminosity (BRIL) system aims to provide high-precision bunch-by-bunch luminosity determination in the harsh conditions of the High Luminosity LHC. Luminosity instrumentation will rely on several CMS subdetectors and subsystems, including a dedicated detector, the fast beam condition monitor (FBCM) with Si-pad sensors and a fast triggerless readout. Various CMS subsystems’ back-ends will be adapted to provide luminosity information, including the tracker endcap pixel detector (TEPX), the outer tracker, the muon barrel, the hadron forward calorimeter, as well as the 40 MHz trigger scouting system. The BRIL Trigger Board will send the luminosity triggers to the entire TEPX, and it will enable the independent operation of FBCM and the innermost layer of TEPX from the rest of CMS at all times by providing a dedicated timing and luminosity trigger infrastructure.