The Phase-2 Upgrade of the CMS Outer Tracker

Abstract

The Large Hadron Collider (LHC), at CERN will undergo major upgrades to be able to deliver peak instantaneous luminosities of about 5 − 7.5 × 10 34 cm −2 s −1 by 2027. This High Luminosity upgrade of the LHC (HL-LHC) is expected to deliver a total of about 3000 − 4000 fb −1 during ten years of operation. At the nominal instantaneous luminosity of the HL-LHC, a single bunch crossing will produce 140−200 proton-proton collisions. The current CMS strip tracker and the CMS Phase-1 pixel detector will not be able to survive the harsh operating conditions of the HL-LHC period. The CMS experiment will install a new silicon tracker for the HL-LHC. The Phase-2 Outer Tracker (OT) will feature increased radiation hardness, higher granularity and track separation and compatibility with higher data rates and a longer trigger latency. In addition, the OT will provide tracking information to the Level-1 trigger, allowing trigger rates to be kept at a sustainable level without sacrificing physics potential. To achieve this, the OT will be made up of modules with two closely spaced sensors read out by a single ASIC. The ASIC will correlate data from both sensors to form short track segments called stubs, to be used in tracking at Level-1. In this contribution, the design of the CMS Phase-2 OT, the technological choices and highlights of the research and development activities will be reported.

Process quality control strategy for the Phase-2 Upgrade of the CMS Outer Tracker and High Granularity Calorimeter

“…The production of AC-coupled strip sensors requires more steps and thus a different process than the production of DC-coupled pixels. For a detailed discussion of the CMS Outer Tracker Phase-2 Upgrade, see [6].…”

The Phase 2 Upgrade of the CMS Inner Tracker

“…Therefore, it has been decided to use two sensor bias lines per chain in the TBPX. 2 A maximum number of five modules with 3D sensors would be biased in parallel with a maximum voltage difference of 5*1.5 V= 7.5 V, which is considered acceptable. For the disks, the granularity of the sensor bias is kept the same with the serial powering: one line will be used to bias in parallel the sensors of a serial power chain (from 5 up to 12 modules, depending on the ring).…”

“…silicon sensors readout by ASICs. The detector system is divided into two subsystems, the Outer Tracker (OT) [2], that is based on silicon strips and macro-pixels, and the Inner Tracker (IT), that is exclusively using pixelated sensors. The new pixel detector will need to withstand up to 1.2 Grad of Total Ionising Dose (TID) and a hadron fluence of 2.3 × 10 16 n /cm 2 and cope with hit rates of up to 3.2 GHz/cm 2 for the innermost layer (30 mm from the beam line), a trigger latency of 12.8 μs E-mail address: styliani.orfanelli@cern.ch.…”

Fully Depleted Monolithic Active Microstrip Sensors: TCAD Simulation Study of an Innovative Design Concept

“…On the other hand, microstrip sensors [ 24 ] are widely used as particle detectors for space applications and are a competitive option for particle trackers due to their high spatial resolution, simpler readout and much lower power density (i.e., power consumption per unit area) compared to pixel detectors. Particle collider experiments have employed silicon hybrid strip sensors in the past and are still developing and assembling new trackers based on this technology, as in the case of the Phase-2 Upgrades of the CMS Outer Tracker [ 25 ] and of the ATLAS Strip Inner Tracker [ 26 ]. Recent space experiments equipped with silicon hybrid microstrip trackers include FERMI-LAT [ 27 ], DAMPE [ 28 ], PAMELA [ 29 ], and AMS-02 [ 30 ].…”