Electronics design and testing of the CMS Fast Beam Condition Monitor for HL-LHC
/ Authors
K. Shibin, G. Auzinger, H. Bakhshiansohi, A. Dabrowski, A. Dierlamm, M. Dragicevic, A. Gholami, G. Gomez, M. Guthoff, M. Haranko
and 17 more authors
A. Homna, M. Jenihhin, J. Kaplon, O. Karacheban, B. Korcsm'aros, A. Lokhovitskiy, R. Loos, S. Mallows, J. Michel, V. Myronenko, G. P'asztor, J. Schwandt, M. Sedghi, A. Shevelev, G. Steinbrueck, D. Stickland, G. Węgrzyn
/ Abstract
The high-luminosity upgrade of the LHC (HL-LHC) brings unprecedented requirements for precision bunch-by-bunch luminosity measurement and beam-induced background monitoring in real time. A key component of the CMS Beam Radiation Instrumentation and Luminosity detector system is a stand-alone luminometer, the Fast Beam Condition Monitor (FBCM), which is able to operate independently at all times with a triggerless asynchronous readout. FBCM utilizes a dedicated front-end ASIC to amplify the signals from CO$_2$-cooled silicon-pad sensors with 1 ns timing resolution. Front-end (FE) electronics are subject to high-radiation conditions, thus all components are radiation hardened: sensors, ASICs, transceivers, etc. The FBCM ASIC contains 6 channels, each outputting a high-speed binary signal carrying the time-of-arrival and time-over-threshold information. This signal is sent via a gigabit optical link to the back-end electronics for analysis. A dedicated test system is designed for the FBCM FE electronics with a modular setup for all testing needs of the project from initial ASIC validation test to system-level testing with the full read-out chain. The paper reports on the design, read-out architecture, and testing program for the FBCM electronics.