Feb 21 – 25, 2022
Vienna University of Technology
Europe/Vienna timezone

The Scintillating Fibre Tracker for the LHCb Upgrade

Feb 22, 2022, 4:50 PM
Vienna University of Technology

Vienna University of Technology

Gusshausstraße 27-29, 1040 Wien
Live Presentation Photon Detectors Large Detector Systems


Lais Soares Lavra (Université Clermont Auvergne (FR))


LHCb is undergoing a major upgrade during LHC LS2 to be completed in February 2022 to cope with increased instantaneous luminosities and a trigger-less 40 MHz read-out to improve on many world-best physics measurements. A light and homogeneous detector based on plastic scintillating fibres will be installed downstream of the LHCb dipole magnet.
The Scintillating Fibre (SciFi) tracker covers an area of 340 m2 by using more than 10,000 km of blue emitting scintillating fibre with 250 μm diameter, enabling a spatial resolution of
better than 80 μm for charged particles and a hit efficency better than 99%. Six-layer fibre mats of 2.4 m length are assembled to form individual detector modules (0.5 m x 4.8 m) consisting of eight fibre mats each. Linear arrays of Silicon Photomultipliers cooled to -40 °C are placed at the fibre ends. The readout of 524k channels occurs through custom-designed front-end electronics with fast 10 ns shaping, dual integrators, and a 3-comparator flash ADC to digitise the signals. An FPGA clusters the signals over threshold and outputs a barycentre to the 40 MHz DAQ farm with a total bandwidth of over 20 Tbits/sec.
At the time of the conference, the tracker assembly will have been completed and installed underground at LHCb. The talk will give a brief overview of the SciFi detector design, production, performance, the experience from the assembly and an early commissioning status.

Primary experiment LHCb

Primary author

Lais Soares Lavra (Université Clermont Auvergne (FR))


Blake Leverington (Ruprecht Karls Universitaet Heidelberg (DE))

Presentation materials