Review of the CMS muon detector system Physics

Review of the CMS muon detector system Ø Physics goals Ø Muon system layout Ø Barrel Drift Tubes Chambers (DT) Ø Endcap Cathode Strip Chambers (CSC) Ø Resistive Plate Chambers (RPC) Ø Installation Ø Conclusions 8 th Topical Seminar on Innovative Particle and Radiation Detectors 21 -24/10/2002 Torassa, INFN Padova Siena, 21 -24 October 2002 Ezio. Siena, Torassa – Sez. INFN di. Ezio Padova

Physics goals The 4 lepton channel is the most promising for SM Higgs 130 m. H 650 Ge. V Siena, 21 -24/10/2002 Ezio Torassa, INFN Padova 2

Physics goals • H g Z Z(*) g 4 SM Higgs (mass resol. ~ 1 Ge. V) • h, H, A g + - SUSY Higgs (mass resol. ~ 1 Ge. V) • ~q , ~ g g multi-lepton + multi-jet + Etmiss Superpartners (muon recognition in multi-jet environment) • Z’ g + - New Gauge Bosons (Pt m measur. and sign determ. Above 1 Te. V) • etc … Siena, 21 -24/10/2002 Ezio Torassa, INFN Padova 3

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

Muon system layout Barrel ( <1. 3) DT - RPC Endcap ( 0. 9< <2. 4) CSC - RPC • particle rates < 10 Hz/cm 2 • particle rates 10 -100 Hz/cm 2 • low B field < 0. 8 T • high B field up to 3 T RPC goals Measure f points along muons track segments in the barrel and endcap regions to: • identify muons and assign a bunch crossing • estimate their pt 1 track segment with 6 f points Efficiency > 95% Time resolution 3 nsec Siena, 21 -24/10/2002 Ezio Torassa, INFN Padova 5

Muon system layout DT goals Measure f 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 f and 4 points single point resol. ~ 250 m track segments precision of 100 m under multiple scattering contribution up to pt = 200 Ge. V CSC goals Like DT but in endcap regions 4 track segment with 6 f and 6 R points single point resol. 120 - 250 m track segment precision 75 m ME 1/1 ME 1/2 (150 m for the others) under multiple scattering contribution up to pt = 100 Ge. V Siena, 21 -24/10/2002 Ezio Torassa, INFN Padova 6

Barrel Drift Tubes Chambers DT Chambers Production sharing 5 4 3 2 6 1 7 12 8 9 10 11 Aachen Madrid Padova Torino 10 Sectors will be installed in SX 5 210 Chambers(420 RPCs). Sectors 1 and 7 are used for the lowering fixture and will be installed in UX 5 40 Chambers(80 RPCs). Siena, 21 -24/10/2002 # chambers 70 70 70 40 (Bologna, Dubna and Protvino) Ezio Torassa, INFN Padova 7

Barrel Drift Tubes Chamber 250 Chambers 172200 Anode ch. Superlayer Siena, 21 -24/10/2002 Ezio Torassa, INFN Padova 8

Barrel Drift Tubes Chambers Drift Tube 42 mm Wire Electrode Strip 13 mm Mylar Drift velocity m/ns Cathode Al Strips Cell designed to have electric field as uniform as possible ò Gas mixture Ar/CO 2 ( 85/15 % ) Vc / Vs / Vw = -1. 2/+1. 8/+3. 6 (k. V) ò E = 1 - 2 k. V/cm Electric field k. V/cm Siena, 21 -24/10/2002 Ezio Torassa, INFN Padova 9

Barrel Drift Tubes Chambers DT performance: last prototype with muon beam Results from July 1999 CERN-H 2 test beam Single cell resol. 170 m ( 3 nsec) The prototype is a narrow MB 2 type superlayer with the final cell design Single cell efficiency 99. 8 % (1% geometrical ineff. removed) Siena, 21 -24/10/2002 Ezio Torassa, INFN Padova Performance confirmed in the Sept. 2001 test beam using the first DT chamber. A new test beam is foreseen in March 2003 10

Barrel Drift Tubes Chambers DT Chamber Production (18 DT/site/year) ea r End: 09/2005 /y Start: 04/2001 Lp =3 6 S 130 80 45/56 Planned Achieved Shortage Torino starts March 2003 Slo pe 180 # SL # Chambers (all sites) hi 230 r pe lo 30 = 18 SL th / S -20 4/1 1/2 2/2 3/2 4/2 1/3 2/3 3/3 4/3 1/4 2/4 3/4 4/4 1/5 2/5 3/5 4/1 = end Q 4 2001, 1/2 = end Q 1 2002 etc. . 14 chambers at CERN (ISR) under HV , 32 chambers within November 5 th Siena, 21 -24/10/2002 Ezio Torassa, INFN Padova 11 a ye

Barrel Drift Tubes Chambers Construction check list Tool Maintenance check list Electronic install. check list Chamber test check list Drift tubes quality control manual and procedures V 7 AACHEN CIEMAT Wire: tension and position SL: HV and gas tightness Chamber, SL: thickness, flatness Every channel: noise, eff. and resolution www. pd. infn. it/dbcms/db Database TORINO LEGNAROwww. physik. rwth-aachen. de/~dbac/ Siena, 21 -24/10/2002 wwae. ciemat. es/cms/Chamber. Cons. Db/db. html Ezio Torassa, INFN Padova Aachen Madrid 12

Barrel Drift Tubes Chambers Gas tightness Pressure drop: 2 hours Pi = pressure at t=0 Pa = pressure after t>0 QC requirement: Now >135 min > 1000 min Dead-Noisy channels 1% Noisy cell: Freq. > 500 Hz/cell Noisy cells + Disconn. Cells < 1% Siena, 21 -24/10/2002 Ezio Torassa, INFN Padova 13

Barrel Drift Tubes Chambers DT full production tested with cosmic rays Typical TDC spectrum for one cell tmax =370 ns Meantime= vdrift 57 m/ns Meantime r. m. s. 400 m (7 nsec) Efficiency ~ 99% Probability for a 4. hit on a track Mean time resol. = 2/3 r. m. s. 325 m Siena, 21 -24/10/2002 Ezio Torassa, INFN Padova 14

Barrel Drift Tubes Chambers 4 tech. + supervisor , half a day/ch Siena, 21 -24/10/2002 Ezio Torassa, INFN Padova 15

Endcap Cathode Strip Chambers 36 sectors # Chambers 72 JINR (Dubna) 144 IHEP (Beijing) 72 (108) PNPI (Petersburg) 144 (216) FNAL, UF and UC 18 sectors ME 4 ME 3 ME 2 ME 1 staged Siena, 21 -24/10/2002 Ezio Torassa, INFN Padova 16

Endcap Cathode Strip Chambers 540 (432*) Chambers 4 disks 2 -3 rings (3 for ME 1) ~ 2. 5 million wires 210816 Anode ch. 273024 Cathode ch. (*)(ME 4 Chamber Trapezoidal shape covers 10 o or 20 o sectors Siena, 21 -24/10/2002 staged) Each Chamber has 6 gas gap planes Ezio Torassa, INFN Padova 17

Endcap Cathode Strip Chambers 9. 5 mm CSC gas gap plane is a multiwire proportional chamber 3. 2 mm H. V. wires 3. 6 k. V (Qcath. 110 f. C, Qanode 140 f. C) Wires measure r-coordinate Wires spaced by 3. 2 mm ganged in groups of 5 -16 Strips run radially to measure f coordinate 3 - 16 mm Strips width 3 -16 mm Gas mixture Ar/CO 2/CF 4 ( 40/50/10 % ) Siena, 21 -24/10/2002 Ezio Torassa, INFN Padova 18

Endcap Cathode Strip Chambers Chamber production status (25 September 2002): 33 / 72 JINR 58 / 144 IHEP 36 / 72 PNPI 110 / 144 Fermilab Start: 05/2000 End: 06/2003 UF, UC 20 chambers shipped to CERN Siena, 21 -24/10/2002 Ezio Torassa, INFN Padova 19

Endcap Cathode Strip Chambers Siena, 21 -24/10/2002 Ezio Torassa, INFN Padova 20

Resistive Plate Chambers Italy: Bari, GT (Naples, Pavia) China: Beijing Bakelite production and quality control Mechanics for RB 1 Assembly and test Gap production and quality control First two wheels assembled in Italy Front-end production RB 2, RB 4 assembly and test RB 4, 120 chambers RB 3, 120 chambers Bulgaria: Sofia RB 2, 120 chambers Mechanics for RB 2, RB 3, RB 4 RB 1, 120 chambers RB 3 Assembly and test Siena, 21 -24/10/2002 Ezio Torassa, INFN Padova 21

Resistive Plate Chambers China The engineering design is ready. EDR in October. RE 1/2 RE 1/3 RE 3/2 RE 3/3 RE 4/2 staged Siena, 21 -24/10/2002 Ezio Torassa, INFN Padova Korea Pakistan 22

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) Resistive electrodes prevents surface sparking damages ò Electrode resistivity Rate capability Gap width ò Vdrop rate • electrode • Operating H. V. Double gap improves efficiency and time resolution 9. 0 k. V • Gap width 2 mm • Bakelite bulk resistivity 1 -2 1010 W cm • Bakelite thickness 2 mm • strip width ~ 35 mm • Gas Siena, 21 -24/10/2002 Time performance 95% C 2 H 2 F 4 , 5% i-C 4 H 10 Ezio Torassa, INFN Padova 23

Resistive Plate Chambers Schedule for wheel # 0: 25 RB 3 => end September 2002 25 RB 1 => end January 2003 25 RB 2 => end March 2003 25 RB 4 => April 2003 From the beginning of 2003 Production rate: 10 chamber/month Test rate: 15 chamber/month First wheel by the end April 2003 Second wheel by the begin of 2004 Production rate: 12 chamber/month Start to assembly RE 1/2 and RE 1/3 Siena, 21 -24/10/2002 Ezio Torassa, INFN Padova 24

Resistive Plate Chambers RPC tested with cosmic rays Efficiency Current Noise Siena, 21 -24/10/2002 Ezio Torassa, INFN Padova 25

Installation 12 MB 1 24 RE 1 12 MB 2 24 RE 2 12 MB 3 24 RE 3 6 MB 4 12 RE 4 Installation windows for MB V 33 Installation Cabling Siena, 21 -24/10/2002 Ezio Torassa, INFN Padova 26

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%, RPCB 4% the small shortage w. r. t. the planning is compatible with the installation planning Siena, 21 -24/10/2002 Ezio Torassa, INFN Padova 27