Review of the CMS muon detector system muon detector system  Physics goals  Muon system layout  Barrel Drift Tubes Chambers (DT)  Endcap Cathode Strip Chambers (CSC)  Resistive Plate Chambers (RPC)  Installation  Conclusions 8th Topical Seminar on Innovative Particle and Radiation Detectors Ezio Torassa – Sez. INFN di Padova Siena, October 2002

Siena, 21-24/10/2002Ezio Torassa, INFN Padova2 Physics goals The 4 lepton channel is the most promising for SM Higgs 130  m H  650 GeV

Siena, 21-24/10/2002Ezio Torassa, INFN Padova3 H  Z Z (*)  4  SM Higgs (mass resol. ~ 1 GeV) h, H, A   +  - SUSY Higgs (mass resol. ~ 1 GeV) q, g  multi-lepton + multi-jet + E t miss  Superpartners (muon recognition in multi-jet environment) Z’   +  - New Gauge Bosons (P t   measur. and sign determ. Above 1TeV) etc … ~~ Physics goals

Siena, 21-24/10/2002Ezio Torassa, INFN Padova4 Muon system layout Barrel: 5 wheels 4 shells 12 sectors Endcap: 4 disks 2-3 wheels

Siena, 21-24/10/2002Ezio Torassa, INFN Padova5 Muon system layout Barrel (  <1.3) DT - RPC particle rates < 10 Hz/cm 2 low B field < 0.8 T Endcap ( 0.9<  <2.4) CSC - RPC particle rates Hz/cm 2 high B field up to 3 T RPC goals Measure  points along muons track segments in the barrel and endcap regions to: identify muons and assign a bunch crossing estimate their p t 1 track segment with 6  points Efficiency > 95% Time resolution  3 nsec

Siena, 21-24/10/2002Ezio Torassa, INFN Padova6 DT goals Measure  and  points along muons track segements in the barrel region to: identify muons and measure charge and momentum identify the bunch crossing associated to every muon track 4 track segment with 8  and 4  points single point resol. ~ 250  m  track segments precision of 100  m   under multiple scattering contribution up to p t = 200 GeV CSC goals Like DT but in endcap regions 4 track segment with 6  and 6 R points single point resol.   m track segment precision  75  m ME1/1 ME1/2 (150  m for the others)   under multiple scattering contribution up to p t = 100 GeV Muon system layout

Siena, 21-24/10/2002Ezio Torassa, INFN Padova7 DT Chambers Production sharing Aachen Madrid Torino Padova 10 Sectors will be installed in SX5 210 Chambers(420 RPCs). Sectors 1 and 7 are used for the lowering fixture and will be installed in UX5 40 Chambers(80 RPCs) Barrel Drift Tubes Chambers (Bologna, Dubna and Protvino) # chambers 70 40

Siena, 21-24/10/2002Ezio Torassa, INFN Padova8 Barrel Drift Tubes Chambers Chamber Superlayer 250 Chambers Anode ch. 

Siena, 21-24/10/2002Ezio Torassa, INFN Padova9 Barrel Drift Tubes Chambers Drift Tube Gas mixture Ar/CO 2 ( 85/15 % ) V c / V s / V w = -1.2/+1.8/+3.6 (kV) Drift velocity  m/ns Electric field kV/cm E = kV/cm   Cell designed to have electric field as uniform as possible Mylar Electrode Strip Cathode Al Strips 42mm 13 mm Wire

Siena, 21-24/10/2002Ezio Torassa, INFN Padova10 Single cell efficiency  (1% geometrical ineff. removed) Barrel Drift Tubes Chambers DT performance: last prototype with muon beam Single cell resol.  m ( 3 nsec) Results from July 1999 CERN-H2 test beam The prototype is a narrow MB2 type superlayer with the final cell design Performance confirmed in the Sept test beam using the first DT chamber. A new test beam is foreseen in March 2003

Siena, 21-24/10/2002Ezio Torassa, INFN Padova11 Barrel Drift Tubes Chambers 4/1 = end Q4 2001, 1/2 = end Q etc.. DT Chamber Production (18DT/site/year) # Chambers (all sites) # SL Slope = 36 SL phi / year Slope = 18 SL th / year Torino starts March chambers at CERN (ISR) under HV, 32 chambers within November 5 th 45/56 Start: 04/2001 End: 09/2005

Siena, 21-24/10/2002Ezio Torassa, INFN Padova12 CIEMAT AACHEN LEGNARO TORINO Barrel Drift Tubes Chambers Drift tubes quality control manual and procedures V7 Construction check list Tool Maintenance check list Electronic install. check listChamber test check list Wire: tension and position SL: HV and gas tightness Chamber, SL: thickness, flatness Every channel: noise, eff. and resolution Database Padova Aachen wwae.ciemat.es/cms/ChamberConsDb/db.htmlwwae.ciemat.es/cms/ChamberConsDb/db.html Madrid

Siena, 21-24/10/2002Ezio Torassa, INFN Padova13 Barrel Drift Tubes Chambers 1% Pressure drop: P i = pressure at t=0 P a = pressure after t>0 QC requirement:    >135 min Now   > 1000 min 2hours Gas tightness Dead-Noisy channels Noisy cell: Freq. > 500 Hz/cell Noisy cells + Disconn. Cells < 1%

Siena, 21-24/10/2002Ezio Torassa, INFN Padova14 Barrel Drift Tubes Chambers t max =370 ns Efficiency ~ 99% Probability for a 4.hit on a track Mean time Typical TDC spectrum for one cell v drift  57  m/ns Meantime r.m.s.  400  m (7 nsec) resol. =  2/3 r.m.s.  325  m DT full production tested with cosmic rays Meantime=

Siena, 21-24/10/2002Ezio Torassa, INFN Padova15 Barrel Drift Tubes Chambers 4 tech. + supervisor, half a day/ch

Siena, 21-24/10/2002Ezio Torassa, INFN Padova16 Endcap Cathode Strip Chambers IHEP (Beijing) PNPI (Petersburg) FNAL, UF and UC JINR (Dubna) ME 4 staged ME 3ME 2ME 1 # Chambers (108) 144 (216) 18 sectors 36 sectors

Siena, 21-24/10/2002Ezio Torassa, INFN Padova17 Endcap Cathode Strip Chambers Each Chamber has 6 gas gap planes Chamber Trapezoidal shape covers 10 o or 20 o sectors 540 (432 * ) Chambers 4 disks 2-3 rings (3 for ME1) ~ 2.5 million wires Anode ch Cathode ch. (*) (ME4 staged)

Siena, 21-24/10/2002Ezio Torassa, INFN Padova18 Endcap Cathode Strip Chambers CSC gas gap plane is a multiwire proportional chamber Gas mixture Ar/CO 2 /CF 4 ( 40/50/10 % ) H.V. wires 3.6 kV (Q cath.  110 fC, Q anode  140 fC) Strips run radially to measure  coordinate Wires measure r-coordinate Strips width 3-16 mm mm 3.2 mm 9.5 mm Wires spaced by 3.2 mm ganged in groups of 5-16

Siena, 21-24/10/2002Ezio Torassa, INFN Padova19 Endcap Cathode Strip Chambers 33 / 72 JINR 58 / 144 IHEP 36 / 72 PNPI 110 / 144 Fermilab UF, UC Chamber production status (25 September 2002): 20 chambers shipped to CERN Start: 05/2000 End: 06/2003

Siena, 21-24/10/2002Ezio Torassa, INFN Padova20 Endcap Cathode Strip Chambers

Siena, 21-24/10/2002Ezio Torassa, INFN Padova21 RB4, 120 chambers RB3, 120 chambers RB2, 120 chambers RB1, 120 chambers Bakelite production and quality control Gap production and quality control Front-end production Italy: Bari, GT (Naples, Pavia) Mechanics for RB1 RB1 Assembly and test China: Beijing Mechanics for RB2, RB3, RB4 RB3 Assembly and test RB2, RB4 assembly and test Bulgaria: Sofia Resistive Plate Chambers First two wheels assembled in Italy

Siena, 21-24/10/2002Ezio Torassa, INFN Padova22 Resistive Plate Chambers China Korea Pakistan The engineering design is ready. EDR in October. RE1/2 RE1/3 RE3/2 RE3/3 RE4/2 staged

Siena, 21-24/10/2002Ezio Torassa, INFN Padova23 Resistive Plate Chambers RPC double gap module Avalanche created inside the gap, charge induced on strips ( Avalanche operation mode can work with higher rates w.r.t. streamer mode) Electrode resistivity  Rate capability Gap widthTime performance  Double gap improves efficiency and time resolution V drop  rate  electrode Resistive electrodes prevents surface sparking damages Operating H.V.  9.0 kV Gap width 2 mm Bakelite bulk resistivity  cm Bakelite thickness 2 mm strip width ~ 35 mm Gas 95% C 2 H 2 F 4, 5% i-C 4 H 10

Siena, 21-24/10/2002Ezio Torassa, INFN Padova24 Resistive Plate Chambers Schedule for wheel # 0: 25 RB3 => end September RB1 => end January RB2 => end March RB4 => April 2003 Schedule for wheel # 0: 25 RB3 => end September RB1 => end January RB2 => end March RB4 => April 2003 Production rate: 10 chamber/month Test rate: 15 chamber/month Production rate: 10 chamber/month Test rate: 15 chamber/month First wheel by the end April 2003 Second wheel by the begin of 2004 First wheel by the end April 2003 Second wheel by the begin of 2004 From the beginning of 2003 Start to assembly RE1/2 and RE1/3 From the beginning of 2003 Start to assembly RE1/2 and RE1/3 Production rate: 12 chamber/month

Siena, 21-24/10/2002Ezio Torassa, INFN Padova25 Resistive Plate Chambers Efficiency Noise Current RPC tested with cosmic rays

Siena, 21-24/10/2002Ezio Torassa, INFN Padova26 InstallationCabling Installation windows for MB V33 Installation 12 MB1 24 RE1 12 MB2 24 RE2 12 MB3 24 RE3 6 MB4 12 RE4

Siena, 21-24/10/2002Ezio Torassa, INFN Padova27 Conclusions CMS muon system has been designed to achieve the LHC physics goals Required performances were obtained with detector prototypes and were confirmed with the produced chambers The production status is: DT 18%, CSC 55%, RPC B 4% the small shortage w.r.t. the planning is compatible with the installation planning