Beam test performance of a prototype module with Short Strip ASICs for the CMS HL-LHC tracker upgrade

Abstract

The Short Strip ASIC (SSA) is one of the four front-end chips designed for the upgrade of the CMS Outer Tracker for the High Luminosity LHC. Together with the Macro-Pixel ASIC (MPA) it will instrument modules containing a strip and a macro-pixel sensor stacked on top of each other. The SSA provides both full readout of the strip hit information when triggered, and, together with the MPA, correlated clusters called stubs from the two sensors for use by the CMS Level-1 (L1) trigger system. Results from the first prototype module consisting of a sensor and two SSA chips are presented. The prototype module has been characterized at the Fermilab Test Beam Facility using a 120 GeV proton beam.

CMS Outer Tracker Phase-2 Upgrade module noise and mitigation

“…The CMS collaboration is targeting a hit efficiency of at least 99.5% [4] on the active sensor region which leads to a very stringent requirement for the analogue channel noise of the final system: <800 electrons (e − ) and <1000 e − for PS-strips and 2S respectively. Noise measurements of modules built from previous hybrid prototypes showed levels acceptable for the hit efficiency targets [5,6] but those earlier prototypes were not representative of the final modules. Modules built with more recent prototypes with all features and optimized for thermal, power and noise performance unexpectedly started showing higher than anticipated noise for the 2S and PS-strip sensors (figure 3).…”