Overview of the CMS beam loss monitoring system (BCML) and diamond detectors surface modification

In CMS a beam loss monitoring system (BCML) is in place to protect the CMS Tracker from potentially damaging, high intensity beam loss events. Above a pre-defined detector current the LHC beams are automatically dumped. Detectors for this system require high radiation tolerance for stability over time, sufficient signal over noise at a given particle rate and a linear response up to the abort threshold. Poly-crystalline (pCVD) diamond sensors are used as detectors. Additionally sapphire based and diamond-on-iridium prototype sensors were installed during 2017 to investigate more radiation tolerant detectors. This report discusses the BCML system, as well as promising ways of solving problems with adhesion to the detector's plates by using the diamond surface modification with doped diamond sublayers.