Transcript LHCb Muon detector

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
2
total active surface of 435 m ) 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 quality control
MWPC
detector
MWPC detector
MWPC assembly
GEM detector
Muon Filters
GEM production
GEM
MWPC
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 bunchcrossing 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.
Track finding by the
muon trigger
MWPC & GEM
GEM and MWPC efficiency
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.
CARIOCA
8 ch (+/-) Amplifier-ShaperDiscriminator. Peaking time ~ 10 ns
SYNC transmits data to DAQ
and L0 trigger
Alessio Sarti. Email: [email protected]
DIALOG
Front End Logic
CARDIAC
Front End Board