stato dei siti di produzione mwpc e quality control
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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
0
5
10
15
20
25
Cha
mbe
r
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
0
10
20
30
40
50
60
12/06/2004 01/08/2004 20/09/2004 09/11/2004 29/12/2004 17/02/2005 08/04/2005
date
cham
ber
num
ber
0
2
4
6
8
10
12
14
16
18
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0 10 20 30 40 50
chamber #
mb
ar/
h
- n
A
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
0
5
10
15
20
25
30
35
Ch
am
ber
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
Cha
mb
er
Christmas3 ch/week
Ch. 43
Updated 8 March
0
50
100
150
200
250
300
Cha
mbe
rs
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
0
10
20
30
40
50
60
70
80
90
100
Cha
mbe
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
0,30
0,50
0,70
0,90
1,10
1,30
1,50
1,70
1,90
0 10 20 30 40 50 60 70 80 90
Chamber
Cur
rent
rat
io
AB CD
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
0 50 100 150 200 250 300 350
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.
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