LHCb Muon Detector

1
LHCb Muon Detector
Institutes Cagliari, CBPF, CERN, Ferrara,
Firenze, LNF, PNPI, Roma "La Sapienza", Roma "Tor
Vergata"

• The task of the Muon System of LHCb is to provide
  (i) a high-Pt Muon candidate for the first
  trigger level (L0) and (ii) a good Muon
  identification for the off-line analysis. The
  system is composed of 5 stations M1-M5 (for a
  total active surface of 435 m2) separated by iron
  filters (iron is only permeable to energetic
  Muons).
• The system is equipped with 1368 Multi-Wire
  Proportional Chambers and 24 triple GEM detectors
  (in the M1 region close to the beam) of 20
  different sizes (from 24x20 cm2 to 148x31 cm2)
  with spatial X-Y readout this results in nearly
  120k FE electronic channels. Most of the MWPCs
  (960) have anode-wire readout, while the others
  have cathode-pad or mixed (anode-wire
  cathode-pad) readout. To ensure efficiency and
  redundancy, all detectors in M1 have two
  sensitive layers in OR, and those in M2-M5 have
  four layers.

MWPC detector
MWPC detector
MWPC quality control
MWPC assembly
GEM detector
Muon Filters
GEM production
GEM and MWPC efficiency
MWPC GEM
MWPC
GEM
The LHCb L0 trigger is based on the 5-fold
coincidence of stations M1 to M5 within 25 ns. It
provides a fast and precise (20 accuracy)
measurement of the Muon Pt and high efficiency
in the bunch-crossing identification. The LHCb
MWPCs and GEMs were designed in order to fulfill
all those requirements. Track finding starts from
M3. A track in M2-M5 is then extrapolated to M1
and to the interaction point to compute the
momentum. The trigger efficiency for b? mX is 46
at 100 kHz output rate. The decision time is 1
ms.
Three custom radiation hard chips have been
developed with IBM 0.25 micron process for use in
the Front-end electronics CARIOCA, DIALOG and
SYNC.
Track finding by the muon trigger
CARIOCA 8 ch (/-) Amplifier-Shaper-Discriminator.
Peaking time 10 ns
DIALOG Front End Logic
SYNC transmits data to DAQ and L0 trigger
CARDIAC Front End Board
Alessio Sarti. Email asarti_at_lnf.infn.it