Stato dei siti di produzione MWPC e quality control

CERN

FERRARA

FIRENZE

LNF

PNPI

Emiliano Dané, Firenze 14 Marzo 2005

Pianificazione della produzione di MWPCChamber planned production overview with spares

R4LNF 40 FIRENZE 70 FERRARA 90

PNPI 200 PNPI 200 PNPI 200LNF 52 FIRENZE 148

R3 LNF 52 FERRARA 52 LNF 52 FERRARA 52 LNF 52

R2 CERN 26 CERN 26 CERN 26 FERRARA 26 FERRARA 26

R1 GEM 24 CERN 14 CERN 14 CERN 14 CERN 14

  M1 M2 M3 M4 M5

PNPI 600 chambers (M2/3/4-R4) LNF 248 chambers (M3/M5-R3, M5-R4, M1-R3/4) Ferrara 246 chambers (M2/4-R3, M4/5-R2, M1R4) Firenze 218 chambers (M5R4 and M1R4) CERN 134 chambers (M2/3-R1/2, M4/5-R1, M1R2)

Total 1446 (circa il 6% di spares)

Status of production at CERN

M3R1: needed=12 (+2 spare). Total chambers built=16.• Completely tested and all GOOD

M3R2: needed=24 (+2 spare).• Complete • 25 tested for leaks (2 will be re-visited);• 8 CHAMBERS tested for gain uniformity

Average rate increasedafter summer 2004From 1 to > 2 chambers/week

Closing date of CERN chambers

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M3R1 M3R2

Leak+Dark curr OK: 40 ch. over 134

M2R2: needed=24 (+2 spare).• Closed 3 chambers (updated 8 March)

Test of CERN chambers with radioactive source

14 chambers M3R1over 16 built tested All GOOD

8 chambers M3R2over 16 built tested All GOOD

The bad winding at the wire spool end causes quite some problem to the wire tension.

Problems

Main reason for the delay is the supplementary amount of work to set-up the lab to pass from a production rate of 1 chamber/week to a rate of 2 chambers/week.

Status of production in Ferrara

M2R3: needed=48 (+4 spare) 49 chambers closed (updated 03-Mar-05).• Gas leakage: 42 chambers tested: 41 chambers are OK• HV training: 39 chambers tested: 36 with I < 20 nA/chamber @ 2.85 kV

3 with wire-pads drawing current

Production rate increasing 2-2.5 ch/week

Built=49; (Leak + HV) OK=36; Unrecoverable=6; To be recovered: 4; To be tested= 3.

Chamber production in Ferrara

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dP/dT @5mbar I (nA/chamber) @2.85kV

Gas leakage & HV test

Requirements dP/dT<2mbar/hr I < 20 nA/chamber @ 2.85 kV

Test of Ferrara chambers @ Roma-2

Source: 90Sr (8 mCi) electrons of ~2.5 MeV Collimated ~2 mm diameter

Test with 90Sr source (in Rome II) : 16 tested : 15 GOOD + 1 RESERVE

The Rome II source test table

is now in Ferrara

8 March

Status of production in Firenze

M5R4: 148 (Firenze) (09-Mar-05): built 30 chambers; first 4 prototypes 26 usableGas leakage: 19 good/25 tested chambersGas leak + HV : 10 good /10 tested

Production rate > 2 chambers/week

Closing date of M5R4 Firenze chambers

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Firenze-M5R4 gain uniformity

Source is 90Sr 5 mCi; 3 current measurements for each wire pad Correction factors (20-30%) are applied to account for electron attenuation going from top to bottom gap.

5 chambers tested moving the source by hand: all classified as GOOD.

Setting up a table for automated test.

6 chambers sent to Frascati for test with 137Cs

Status of production in LNFM3R3: needed=48 (+4 spare). Built: 58 chambers56 tested with source (Roma-1 device): 52 are GOOD; 4 are RESERVE

M5R3: needed=48 (+4 spare). Built 45 chambers (13-Mar-2005).40 chambers have been fully-tested and ALL satisfy the requirements:Gas leaks P < 2mbar/hr. Dark current I < 2 nA/gap @ 2.85 kV.GOOD gain uniformity

M5R3: high production rate 3 chambers/week

Tested for Gas Leak andDark current:92 ch. over 248 to be built

Closing date of LNF-M5R3 chambers

048

121620242832364044

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Christmas3 ch/week

Ch. 43

Updated 8 March

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M5R3 (up to now) M5R3-R4 (2/w) M1R3-R4 (3/w)

Switch to M1and Christmas

today

Start M5R4

SummerEaster

Easter

Summer

Start M1R4

LNF production schedule (updated 8-Mar-05)

56 M3R3 + (52+5) M5R3 + 52 M5R4 + 52 M1R3 + 42 M1R4 = 259

2 weeks (Christmas) + 1w Easter + 4w Summer Switch to M1 ~ 1 month

End M5R3=begin-May-05 End M5R4=end-Nov-05 End ALL=mid-sep-06

Assuming a rate of 3 ch./week also for M5 chambers: expected end is ~ mid July 2006

All 38 tested chambers are GOOD

LNF chambers gain uniformity

4 RESERVE CHAMBERS (14, 39, 44, 58)52 GOOD CHAMBERS

M3R3

M5R3

8 March

The container nearly full (90 chambers over 108)

Last Friday we switched on a group of 18 M3R3 chambers (one trolley) using a single HV channel.

These chambers have been OFF and flushed with Argon for severalmonths.~10 days ago we began to flush them with gas mixture 40/40/20.

We reached 2.75 kV (in 2 days)without any problem.

Closing dates of PNPI-1 chambers

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rM3R4: needed=192 (+8 spare).• Assembled: 110 chambers (08-Mar-2005)• Leak and HV test: 110 tested @ 2.95 kV and are OK.

Status of production at PNPI

Present production rate : 4 chambers/week

Gas leakage & Dark current

Requirement:dP/dT<2mbar/hr@ 5 mbar

Requirement:I < 50 nA/chamber@ 2.95 kV

Gas gain uniformity

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Tested with radioactive source: 87 tested 85 GOOD

Updated 1-Feb

PNPI-2 starting with production of M2R4 chambers

PRODUCTION PLAN

100 M3R4 Produced

100 M2R4 Dec 20,2005

100 M4R4 Jan 15, 2006

Plan Production of PNPI

TRANSPORTATION PLAN

Mar 10,2005 102 M3R4

Oct 20 ,2005 56 M2R4 + 46 M4R4

Jan 20, 2006 48 M2R4 + 54 M4R4

May 15,2006 98 M3R4 + 4 M2R4

July 1, 2006 76 M2R4 + 26 M4R4

Aug 5, 2006 16 M2R4 + 74 M4R4

HALFPRODUCTION

COMPLETEPRODUCTION

200 M3R4 August 1 , 2005200 M2R4 July 15 ,2006200 M4R4 August 1,2006

Produzione attuale di MWPC

R4LNF 40 FIRENZE 70 FERRARA 90

PNPI-1 200 PNPI-1 55% PNPI-2 200LNF + FIRENZE 5%

R3 LNF 52 FERRARA 70%LNF

COMPLETATAFERRARA 52 LNF 80%

R2 CERN 26 CERN 11.5%CERN

COMPLETATAFERRARA 26 FERRARA 26

R1 GEM 24 CERN 14CERN

COMPLETATACERN 14 CERN 14

  M1 M2 M3 M4 M5

PNPI 600 chambers (M2/3/4-R4) LNF 248 chambers (M3/M5-R3, M5-R4, M1-R3/4) Ferrara 246 chambers (M2/4-R3, M4/5-R2, M1R4) Firenze 218 chambers (M5R4 and M1R4) CERN 134 chambers (M2/3-R1/2, M4/5-R1, M1R2)

Total 1446 (circa il 6% di spares)

Updated 14.March.2005

110

0

92

36

10

40

214

276

156

210

208

94

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PNPI1

PNPI2

LNF

Ferrara

Firenze

CERN

Chambers

The 10% milestone (140 ch) has been reached on 16.11.2004 (delay 7.5 months)

Produzione attuale di MWPC

Total: 288 chambers built and testedExpected production rate is ~ 2 ch/week in INFN and CERN and 4 ch/week in PNPITotal rate INFN+CERN+PNPI-1 should be 12 chambers/week

Production is progressing well : Since last LHCb week +140 chambers built –10.7 ch/week [12 expected, Christmas included – was 7.5 ch/week]

 ASSEMBLE

DSpecial extras

Useful Full test OK Partial test Bad

          OK  

PNPI 112 0 112 110 2

LNF 103 6 99 96 4 2

FE 49 0 43 36 8

FI 30 0 21 10 9 5

CERN 45 2 40 14 26 0

             

  339 8 315 266 39 17

Production overview

1. Preparation in labs: FEE electronics, LV and Faraday Cage must be assembled on chamber (and tested).Part of this work will be done at the production sites:at Roma-2 and LNF for whole INFN production, at PNPI and at CERN. The first chambers will be equipped as soon as the CARDIAC boards will be available.

2. Shipping of MWPCs: INFN chambers to CERN: in special trolleys with shock absorbers stocked in a container (see photo).Shipping of PNPI chambers: in wooden boxes (CSC-CMS like)

3. Tests at CERN:Storage at CERN: about 200 m2 available. Stored under gas flux.Tests: check no-damage in transportation: test on FEE and last test with HV\

We have yet to deploy a detailed plan for these tests:• check the time and the personnel needed; • logistics at CERN and the infrastructure needed (gas, HV, etc...)

Chamber preparation prior to installation

TRASPARENZE DI RISERVA

Built Usable HV     Scan    

    OK BAD To test OK Reserve To test

Fe/Pz 50 43 33 1 9 15 1 16

LNF 103 99 96 2 4 90 4 4

PNPI-1 112 112 101   11 104 1 7

CERN 43              

FI  28    7  2  19      28

Concerns : • PNPI2 not yet fully started (should have happened in January)• Too slow test in FI/RM2 (HV + source) and FE/RM2 (source) : if there is a problems, it is identified too late !• Schedule tight but not unreasonable – Room for recovery • CERN and FI should put their data on a DB !

Quality controls: MWPC specifications

(From W. Riegler simulations, EDR – CERN – April 2003)

The drift velocity is saturated I.e. it has a very weak dependence on the electric field. Therefore we mainly worry about gas gain variations that can move the working point within the plateau.

If G0 is the nominal gas gain, requiring :

G0/1.25 < G < G0*1.25 (in 95% of the gap area)G0/1.50 < G < G0*1.50 (in 5% of the gap area)

translates into specifications of gap (panel planarity): 95% in ±90 m 5% in ±180 m pitch: 95% in ±50 m 5% in ±100 m wire y-offset: 95% in ±100 m 5% in ±200 m wire plane y-offset: 95% in ±100 m 5% in ±200 m

Wire pitch measurement

The wire position is precisely determined by the pitch of the wiring machine combs.The requirement on the wire pitch (WP) is:WP = 2 mm ± 50 µm (95% of pitches) ± 100 µm (5% of pitches)

The WP is measured with an automatic device, based on two cameras scanning the panel. An accuracy of about 20 µm is obtained.

2mm

Sample image from scanning device

2 mm ± 50 µm 211 ± 5 pixels.

Fraction of wires with wrong pitch < 1 per mil

Wire tension measurement (I)

The wire mechanical tension must be in the range 50÷90 g in order to provide a good electrostatic stability. The tension is found by measuring the wire resonance frequency. Different methods are used.

LNF: oscillations of the wire to be tested are induced by applying a periodicHV (about 900 V) with a frequency of 300 ÷ 400 Hz, between the wire and anon-oscillating sense wire parallel and close (~1 mm) to it. As a consequence,the capacitance C between the two wires oscillates. The maximum variationof C occurs at the resonance of the wire.Resolution is ~1 g and a M3R3 panel (660 wires) is measured in < 1 hour.

Laser

Photodiode

wire

Mechanical excitation

Panel

This method has been developed together with Firenze and Roma II

The signal is sent to a PC soundcard, a FFT is applied.The resonance frequency is searched between 310 and 600 Hz (for M2R3 panels).

Wire Tension Measurement (II)Wire Tension Measurement (II)

Laser

Mechanical

Excitation

Photodiode

The measurement takes about 2 sec/wire ( 2 panels ~1200 wires in 40 min )

Gas leakage test (I)

In order to minimize the gas refill rate, the maximum leakage allowed for each chamber is 2 mbar/h.

To verify the gas tightness of a chamber, we inflate it with nitrogen up to an overpressure P of 5 mbar.Then, we record P as a function of time, during about one hour.

The measurement is sensitive to variations of the external temperature. In order to correct this effect, a second chamber is used as a reference.

HV training and Dark current

LNF : all chambers with dark current < 10nA/chamber @ 2.85 kV

Procedure for conditioning of the chambers:1) Start with HV+ and go to HV at which the current reaches 200 - 300 nA and does

not show the tendency to fast decrease (Normally this happens @ 2.6 - 2.7 kV)2) Switch to HV- and start from HV=0 to increase first quite fast (200 V/min)

up to 1.5 kV. 3) Increase HV slowly till the current jumps to some value which SHOULD NEVER

EXCEED 3-4 A.4) Stop and wait till current drops to 50-100 nA. Normally this takes small time.

Then make the next step (~100 V) and so on.The training stops at HV= 2.15 kV.

The procedure with the inverse polarity takes not more than one hour.After that they go to the normal polarity. In most cases HV=2.95 kV can be reachedafter such training. If not, a second round with the inverse polarity can be performed. Anyhow, the whole procedure allows to reach 2.95 kV in one day.

PNPI : all chambers < 100nA/chamber @ 2.95kV [Ar(40)/CO2(50)/CF4(10)]

Plateau width (M2-M5)

From testbeams: plateau width=170 V for bigaps; 150 V for 4-gaps

Testbeam oct. ’03: BIGAP

Lower plateau limits: 95% for bigap (2.53 kV) / 99% quadrigap (2.55 kV)

Upper limit: cluster size in quadrigap < 1.2 HV <2.7 kV (calculated from oct’03 results on the bigaps)

GIF july ’04: 4-GAP

2.62 ± 0.075 kV

99%

Plateau width (M1)

GIF july ’04: DOUBLE-MONOGAP

FROM GIF: Lower plateau limit: =99% in double-monogap HV=2.65 kV

FROM OCT’03 (BIGAP): Upper limit: cluster size =1.2; in bigap HV~2.82 kV

Work point ~ 2.72 kV Plateau width ~ 170 V

Testbeam oct. ’03 : BIGAP

Test with cosmic rays (LNF)

The use of a cosmic ray stand allows to measure:- efficiency- time resolution- average hit-multiplicity - electronics noise The system allows to house and test up to six chambers simultaneously (600 channels).

The trigger is given by three large scintillators (one above and two below the chambers) read out on both sides.The trigger rate is of about 15 Hz and its time resolution is about 2.8 ns.

time spectrum

We tested only few chambers, because we do not have still the final FEE. We plan to test all (or part of the) chambers, after the final FEE and the Faraday cage will be mounted on them.This is stillunder discussion.

Tests at GIF of a LNF chamber

GIF: 137Cs and ~100 GeV muon beamOne M3R3 chamber (LNF) tested in July’04 (Public Note LHCb-MUON 2005-003)

Results for the LNF chamber: > 98% and time r.m.s. < 4 ns in the worst background conditions: HV > 2.6 kV

The effect of dead-time due to electronics can be studied also for hottest region M1R2. This is nottrue for the space-charge effect.

Firenze-M5R4 gain uniformity

The 4 tested chambers are classified as GOOD

Cu

rren

t fa

ctor

Source is 90Sr5 mCi3 current measurements for each wire pad

Correction factors (20-30%) are applied to account for electron attenuation going from top to bottom gap.