cms barrel resistive plate chambers - from assembly to operation

5 – 10 June 2007 Primorsko, Bulgaria

National ConferenceOn Particle Physics II

Anton Dimitrov

CMS Barrel Resistive Plate Chambers -

from Assembly to Operation

ANTON DIMITROV



Anton Dimitrov

CMS



Anton Dimitrov

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



Anton Dimitrov

Resistive Plate Chambers



Anton Dimitrov

Double Gap DesignSingle Gap

Single Gap

Readout strips

FW - up BW - up

FW - down BW - down

GAS GAP GAS GAP

GAS GAP GAS GAP

HV electrodes (graphite)

Bakelite

Signal Strips

Gas

-HV

-HV



Anton Dimitrov

RPC Test Overview

1) Cosmic Tests after chamber construction – Bari, Pavia, Sofia

2) Transportation to CERN – Quality test at ISR

3) Coupling – test after coupling

4) Test after transportation to SX5

5) Chamber Installation – Precommissioning test after installation

6) Final Cabling – test after final cabling

7) Lowering down the wheel – test after the lowering

8) LV Test after the cabling, test of DCS cables.

9) Tower Test

10) MTCC



Anton Dimitrov

Barrel production

GTHT

Bari

Pavia

Sofia

ISR

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)

Double gap

GT

Chambers production and quality

certification involve several steps.

China

Single gap

Chamber Assembling Sites



Anton Dimitrov

1.RPC Tests with Cosmics

Trigger scintillator


RPC

μ

1. Efficiency2. Cluster size3. Noise rate4. Dark Current

Main RPC Parameters:



Anton Dimitrov

Trigger System - Bari



Anton Dimitrov

Main RPC Parameters



RPC

μ

1. Efficiency2. Cluster size3. Noise rate4. Dark Current

Main RPC Parameters:



Anton Dimitrov

RPC Parameters



Anton Dimitrov

CMS Requirements

≤ 45 %Humidity

≤ 5 Hz/cm2Intrinsic Noise Rate

≥ 1 kHz/cm2Rate Capability

≥ 95 %Efficiency

≤ 2 nsTime Resolution

CMS RequirementsItem

≥ 300 VHV Plateau

≤ 10 %Streamer Probability



Anton Dimitrov

RPC Results 2006



Anton Dimitrov

2.Transportation to CERN

ISR RPC storage and test area



Anton Dimitrov

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



Anton Dimitrov

RPC – current stability



Anton Dimitrov

Noise rate performance



Anton Dimitrov

3.Coupling DT - RPC



Anton Dimitrov

4.Transportation to SX5



Anton Dimitrov

Before Installation



Anton Dimitrov

5.Chamber Installation



Anton Dimitrov

5.After Installation



Anton Dimitrov

5.Test after Installation



Anton Dimitrov

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



Anton Dimitrov

Precommissioning Results



Anton Dimitrov


Initial Behaviour After the change of the HV connector



Anton Dimitrov




Anton Dimitrov


RB4++_down



Anton Dimitrov

6.Final Cabling

HV cablesLV cablesDCS cablesSignal cables



Anton Dimitrov

Final Cabling Test



Anton Dimitrov

HV Cable Problem

Return wires

HV wires

shield

7,5 mm

Plastic jacket

shield

Al/PET

HV wires Slide by D. Piccolo



Anton Dimitrov

On detector HV cables Problem

First pre-production 40 cableswith correct connections. Starting from the final productionthe connections were inverted !!

gnd

HV wires (thicker) Return wires (thiner)

gndCorrectconnection

Test done at factory:- Continuity test pin to pin- HV test at 15 KV

gnd gnd

HV wires (thicker) Return wires

Wrongconnection

Slide by D. Piccolo



Anton Dimitrov

Present Status

Produced ChambersProduced Chambers 485485

InstalledInstalled 462462

Ready for installationReady for installation 1818

ReinstalledReinstalled 33

SpareSpare 22

Chamber Production and Cosmic Ray Tests are finished!



Anton Dimitrov

Tower Test

Newly established procedure for detector performance, using the final rpc/trigger system:

Strip Connectivity TestSignal Cable Check OutNoise rate as a function of HV and threshold.



Anton Dimitrov

Noise histogram



Anton Dimitrov

Strip Connectivity Test



Anton Dimitrov

MTCC

Magnet TestTest Magnet Functionality – cooling, supply, control systemsMagnet mapping

Cosmic ChallengeReading & Synchronization signals from all subdetectorsTest of the Muon System – RPC, DT, CSCTest of the “cosmic” triggerVerification of Chamber Performance



Anton Dimitrov

MTCC Phases

MTCC I – Local DAQ (Tracker, DT, RPC, CSC)Link Boards, Synchronization, Data TakingBarrel – 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



Anton Dimitrov

MTCC Event



Anton Dimitrov

Noise profile

Noisy FEB before threshold setting

The same FEB after setting of thresholdsPlots by Roselli



Anton Dimitrov

Noise study for a single chamber

RB2IN-B wheel1-RB2IN-B wheel1-

Sector10Sector10

1.1. Noise distribution Noise distribution

calculated on the calculated on the

entire period of entire period of

the MTCC. the MTCC.

2.2. Noise ProfileNoise Profile

Figure 1

Including all the runsIncluding all the runs



Anton Dimitrov

Preliminary Results – Local and Global

EfficiencyRPC

DT



Anton Dimitrov

MTCC Efficiency

Slide by Tupputi

HV at 50 % efficiency

DT-RPC alignment is needed



Anton Dimitrov

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

cms barrel resistive plate chambers - from assembly to operation

Documents