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CMS Barrel Resistive Plate Chambers - from Assembly to Operation. ANTON DIMITROV. CMS. Muon System. Barrel 5 Wheels (-2,-1,0,1,2) 12 Sectors 4 Stations (RB 1,2,3,4) 2 RPC in station => 480 Barrel chambers in total. Resistive Plate Chambers. Single Gap. Readout strips. -HV.
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CMS Barrel Resistive Plate Chambers -from Assembly to Operation ANTON DIMITROV National Conference On Particle Physics II
CMS National Conference On Particle Physics II
Muon System Barrel 5 Wheels (-2,-1,0,1,2) 12 Sectors 4 Stations (RB 1,2,3,4) 2 RPC in station => 480Barrel chambers in total National Conference On Particle Physics II
Resistive Plate Chambers National Conference On Particle Physics II
Single Gap Readout strips -HV Single Gap BW - up FW - up GAS GAP GAS GAP GAS GAP GAS GAP FW - down BW - down -HV HV electrodes (graphite) Bakelite Signal Strips Gas Double Gap Design National Conference On Particle Physics II
RPC Test Overview • Cosmic Tests after chamber construction – Bari, Pavia, Sofia • Transportation to CERN – Quality test at ISR • Coupling – test after coupling • Test after transportation to SX5 • Chamber Installation – Precommissioning test after installation • Final Cabling – test after final cabling • Lowering down the wheel – test after the lowering • LV Test after the cabling, test of DCS cables. • Tower Test • MTCC National Conference On Particle Physics II
Barrel production China ISR Chambersproduction and quality certification involve several steps. Pavia Sofia GT Bari Single gap GT Double gap HT Chamber Assembling Sites Chamber Test Sites RB1 in Pavia RB2 & RB4 in Bari RB3 in Sofia (& Bari) 120 RB1 at HT 240 RB2 and RB4 at GT 120 RB3 in Sofia (& Bari) National Conference On Particle Physics II
Trigger scintillator RPC Trigger scintillator 1.RPC Tests with Cosmics μ Main RPC Parameters: • Efficiency • Cluster size • Noise rate • Dark Current National Conference On Particle Physics II
Trigger System - Bari National Conference On Particle Physics II
Trigger scintillator RPC Trigger scintillator Main RPC Parameters μ Main RPC Parameters: • Efficiency • Cluster size • Noise rate • Dark Current National Conference On Particle Physics II
RPC Parameters National Conference On Particle Physics II
Item CMS Requirements Time Resolution ≤ 2 ns Efficiency ≥ 95 % Rate Capability ≥ 1 kHz/cm2 Intrinsic Noise Rate ≤ 5 Hz/cm2 Humidity ≤ 45 % Streamer Probability ≤ 10 % HV Plateau ≥ 300 V CMS Requirements National Conference On Particle Physics II
RPC Results 2006 National Conference On Particle Physics II
RPC Results 2006 National Conference On Particle Physics II
2.Transportation to CERN ISR RPC storage and test area National Conference On Particle Physics II
2.Quality Tests at ISR • Final dressing • Final cooling • HV connectors • Temperature sensors • Detector control • Gas leak • Threshold setting and reading • Current vs. HV • Long stability test (15-20 days @ 9200 V) • Gas input overpressure test • Performance • Noise rate (cluster count.) vs. HV National Conference On Particle Physics II
RPC – current stability National Conference On Particle Physics II
Noise rate performance National Conference On Particle Physics II
3.Coupling DT - RPC National Conference On Particle Physics II
4.Transportation to SX5 National Conference On Particle Physics II
Before Installation National Conference On Particle Physics II
5.Chamber Installation National Conference On Particle Physics II
5.Chamber Installation National Conference On Particle Physics II
5.Chamber Installation National Conference On Particle Physics II
5.After Installation National Conference On Particle Physics II
5.Test after Installation National Conference On Particle Physics II
5.Precommissioning at SX5 • Gas system • Commissioning of the final gas distributor • Gas line equalization • HV test • Current vs HV, current stability for 48 hours • LV test • Thresholds reading/writing • Noise measurement • Front-end electronics • Strip connectivity National Conference On Particle Physics II
Precommissioning Results National Conference On Particle Physics II
Precommissioning Results Initial Behaviour After the change of the HV connector National Conference On Particle Physics II
Precommissioning Results National Conference On Particle Physics II
Precommissioning Results RB4++_down National Conference On Particle Physics II
6.Final Cabling • HV cables • LV cables • DCS cables • Signal cables National Conference On Particle Physics II
Final Cabling Test National Conference On Particle Physics II
HV Cable Problem HV wires shield shield Return wires Al/PET Plastic jacket Slide by D. Piccolo HV wires 7,5 mm National Conference On Particle Physics II
On detector HV cables Problem Correct connection gnd gnd HV wires (thicker) Return wires (thiner) First pre-production 40 cables with correct connections. Starting from the final production the connections were inverted !! Test done at factory: - Continuity test pin to pin - HV test at 15 KV Wrong connection gnd gnd HV wires (thicker) Slide by D. Piccolo Return wires National Conference On Particle Physics II
Present Status Chamber Production and Cosmic Ray Tests are finished! National Conference On Particle Physics II
Tower Test • Newly established procedure for detector performance, using the final rpc/trigger system: • Strip Connectivity Test • Signal Cable Check Out • Noise rate as a function of HV and threshold. National Conference On Particle Physics II
Noise histogram National Conference On Particle Physics II
Strip Connectivity Test National Conference On Particle Physics II
MTCC • Magnet Test • Test Magnet Functionality – cooling, supply, control systems • Magnet mapping • Cosmic Challenge • Reading & Synchronization signals from all subdetectors • Test of the Muon System – RPC, DT, CSC • Test of the “cosmic” trigger • Verification of Chamber Performance National Conference On Particle Physics II
MTCC Phases • MTCC I – Local DAQ (Tracker, DT, RPC, CSC) • Link Boards, Synchronization, Data Taking • Barrel – One Sector (10) in Wheel+1 and One Sector (10) in Wheel+2 • MTCC II – Global DAQ (Ecal, Hcal, DT, RPC and CSC included) • Barrel – Two Sectors (10&11) in Wheel+2 and One Sector (10) in Wheel+1 National Conference On Particle Physics II
MTCC Event National Conference On Particle Physics II
Noise profile Noisy FEB before threshold setting The same FEB after setting of thresholds Plots by Roselli National Conference On Particle Physics II
Noise study for a single chamber • RB2IN-B wheel1-Sector10 • Noise distribution calculated on the entire period of the MTCC. • Noise Profile Including all the runs Figure 1 National Conference On Particle Physics II
RPC DT Preliminary Results – Local and Global Efficiency National Conference On Particle Physics II
MTCC Efficiency HV at 50 % efficiency DT-RPC alignment is needed Slide by Tupputi National Conference On Particle Physics II
Conclusions • Cosmic Ray Tests in Bari/Pavia/Sofia are finished • Chamber Production is finished • 462 Chambers Installed in CMS • 18 Chambers Ready for Installation • All Five Wheels are fully precommissioned • Tests in the underground cavern started • Tower Test with the final rpc/trigger chain initialized • MTCC Data are being processed National Conference On Particle Physics II