Abstract
The High Luminosity LHC (HL-LHC) will deliver a luminosity of up to 5 × 10 34 cm −2 s −1 , with an average of about 140 overlapping proton-proton collisions per bunch crossing. These extreme pileup conditions place stringent requirements on the trigger system to be able to cope with the resulting event rates. A key component of the CMS upgrade for HL-LHC is a track trigger system, able to identify tracks with transverse momenta above 2 GeV/c already at the first-level trigger. We present here the status of the implementation of a prototype system, based on the combination of Associative Memory custom ASIC and modern Field Programmable Gate Array (FPGA) devices, with the purpose to demonstrate the concept based on state-of-the-art technologies, and to direct the efforts of the necessary R&D toward a final system.
Highlights
The increase of the luminosity of the Large Hadron Collider (LHC) to 5 × 1034 cm−2 s−1, foreseen in the High Luminosity (HL) upgrade scheduled for 2026, will bring up the number of proton-proton interactions per bunch crossing to an average of about 140 and a maximum of about 175
When a charged particle passes through the Silicon Tracker, it releases a small amount of energy in the silicon sensors, and the passage of the particle is recorded (“hit”)
The FNAL Pattern Recognition Mezzanine (PRM) is equipped with a powerful Field Programmable Gate Array (FPGA) with high speed serial links with data rates up to 16.3 Gbit/s, and the synthesized FPGA code has been designed with a low latency approach
Summary
The increase of the luminosity of the Large Hadron Collider (LHC) to 5 × 1034 cm−2 s−1, foreseen in the High Luminosity (HL) upgrade scheduled for 2026, will bring up the number of proton-proton interactions per bunch crossing to an average of about 140 and a maximum of about 175. One solution could come from the use of high-resolution spatial information from silicon trackers, at the cost of adding a few microseconds of latency and with a large data rate compared to the current L1-trigger. Each proton-proton interaction can generate hundreds of charged particles so that the Silicon Tracker generates thousands of hits in each event. The CMS outer tracker will be divided in 48 regions in η-φ (pseudo-rapidity and azimuthal angles) called trigger towers. Such a demonstration will make use of reasonable extrapolations of the technology progress and cost of commercial devices, and the assumption of a strong R&D of the AM chip
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
