Davide Piccolo INFN Napoli Muon Annul Review Cern 15 September 2003 Chamber Production QA/QC MUON...

Davide PiccoloINFN Napoli

Davide PiccoloINFN NapoliMuon Annul Review

Cern 15 September 2003

Muon Annul ReviewCern 15 September 2003 Chamber Production QA/QC

Chamber Production QA/QC

“MUON ANNUAL REVIEW”

On

RESISTIVE PLATE CHMABERS

CERN, 15 September 2003

CHAMBER PRODUCTION

QA/QC

Davide Piccolo INFN Napoli






• Chamber assembly operations

• Assembly sites:• QA procedures• QC procedures

• Test sites• QC procedures

• Summary of the test results

• Conclusions

OUTLOOK OF THE TALK






BW

FW

RB4 about 120 chambers (2 double gaps per chamber)

RB3 120 chambers (2 double gaps per chamber)

RB2 60 chambers (2 double gaps per chamber) + 60 chambers (3 double gaps per chamber)RB1 120 chambers (2 double gaps per chamber)

60 sectors

Basic numbers






HV connections

Before installation ofHV connector:1 HV connection per gap;

After installation ofHV connector:1 HV connection per 2 gaps;

gnd gnd-HV

-HV






• Single gaps and double Gaps produced at GT

• 3 chamber assembly sites:• GT: under control of Bari group (RB2 & RB4)• Bari/Sofia: under control of Sofia group (RB3)• HT: under control of Napoli group (RB1)

• 2 cosmics test sites:• Bari• Pavia

GTHT

Bari

Pavia

Assembly and test sites

Sofia






Chamber production status

20 RB1 chambers have to be modified (11 already modified at HT)See later for the problem found 20 chambers ready to be tested

4 chambers under test at PAVIA

Assembled chambers

Tested chambers






QA/QC procedures at assembly sites

• Assembly site of Bari working since 2002 under control of the Bari Group and of the Sofia group for RB3 assembly.

• Assembly site of GT working since begin of 2003 under control of Bari group

• Assembly site of HT working since June 2003 under control of Napoli group

• Extensive training of the factories involved in the construction and continuous support of Physicists from the groups to guarantee high quality of the chamber production

Double gaps inventory

Cooling system test Gas flow test

LV system test Kapton-FEB connectivity test

DB update

HV test:I vs HVI vs time Noise rate strip by strip

QC during assembly

Check list filling

assembly

QC after assembly






• Double gaps positioning (2/3 DG per chamber)

• Bar installation

• Cooling pipe installation (leak test up to 20 Bars)

• Gas pipe insertion (gas flow test)

• Front-end board connection

• LV and Slow control cabling (LV test)

• Check Front-end/kapton connectivity

Chamber Assembly






Chamber assembly Check list






• I vs HV scan

• monitor of dark current at working voltage for one hour

• Check of dead or noisy channels: single rate strip by strip at working voltage

• Labview program control the tests and save results on PC

HT assembly site – Chamber Quality Control






HV tests (typical chamber)

Chamber 40

Dark current

At 9800 V.






HV test acceptance

REJECTED

First 7 chambersAssembled at HT






Noise measurement

A small frequencymeter has been realized in Napoli.• Test of all the electronic channels of the chamber.• Measurement of the single rate Strip by strip

Check dead and noisy channels

A 288 channels frequencymeter

with interface to PC is under Development in Napoli

Test of a complete chamber






Data Base update






QA/QC procedures at test sites

• Site of Bari is testing chambers since 2002. About 70 chambers tested.

• Site of Pavia is starting to test chambers. First group of 4 chambers under test.

HV connector mounting

DB update

Detector control

I vs. HVI vs. timeSingle rate vs. HV (strip by strip)T, P, Humidity mon.

Cosmic test

Efficiency vs. HV: - single gap - double gapCluster size vs. HvLocal efficiency withtracking

Chamber performances

Go to CERN

REJECTED ACCEPTED






Bari Test site






Typical results






Efficiency distribution: summary

HV workingvoltage

Lower efficiencydue to systematicEffects.






Test performances with tracking

Work is in progress to clean the cosmic data sample selectinggood tracks crossing the test station.RPCs under test can be used to reconstruct the cosmic track.

Select tracks with at least 4Layers (do not require layer under test)

Shift due to geometry and sample purity

Tracking

No tracking

Work in progress






Dark current distribution: summary

working voltage

Dark currentDistribution At working voltage9400 V.

Dark current at working voltage

0

10

20

30

40

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16

Dark current (uA)

nu

mb

er

of

RP

Cs

rejected

accepted






Noise distribution: summary

accepted

rejected






Cluster distribution: summary

HV workingvoltage






Chamber stability

Monitor of the Dark current for several days






Problems

In some of the first chambers tested, dangerous increase of dark currentduring time.

Opened some chamber to understand the problem

Bad insulation: discharge between HV and strip ground

Burned area






Discharge protection

All the chambersalready assembledhave been modified.

Protectionapplied to all the gaps






Pavia test site

Up to 5 chambersTested at the same time






Efficienza gap up layer2

0

10

20

30

40

50

60

70

80

90

100

8 8,5 9 9,5 10HV (kV)

eff

(%)

RPC 2

RPC 3

RPC 4RPC 5

First 4 chambers under test.

First results

Efficiency vs HV

Upper gap






Final tests at ISR

Accepted chambers are sent to CERN and tested again at ISR.

• I vs HV• I vs time• data taking with cosmics (work in progress)

About 70 chambers At moment at ISR

Chambers at ISR under test






Long term stability test

Isobuthanemissing

Time (hours)






Conclusions

114 chambers assembled

74 chambers tested

70 chambers at ISR

HT assembly site working since june 2003 (will produce RB1 chambers under the responsability of Napoli group)

Pavia test site is ready. Four chambers at moment under test

Problems found:

• Discharge between HV and frame for bad insulations. Problem solved with pet protection (9 chambers still to modify)

• In some case broken channels found after transportations (fixed in test sites or at ISR)

Davide Piccolo INFN Napoli Muon Annul Review Cern 15 September 2003 Chamber Production QA/QC MUON...

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