The Assembly of ATLAS Muon chambers @NIKHEF

Marcel Vreeswijk (NIKHEF)

• The NIKHEF Muon Mission• Chamber assembly • Assembly QA• Assembly QC• Summary, Status and Plans

The Assembly of The Assembly of ATLAS Muon chambersATLAS Muon chambers

@NIKHEF@NIKHEF

The Assembly of The Assembly of ATLAS Muon chambersATLAS Muon chambers

@NIKHEF@NIKHEF


NIKHEF Muon Mission

West side has expansion length o 0.1m in Xras

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Construct: 96 Barrel Outer Large (BOL) chambers

High Mechanical Precision: 20m RMS on wire positions

This talk: This talk: BOL-0, BOL-1 and Serial ProductionBOL-0, BOL-1 and Serial Production

2m

5m

BOL=spacer+2x3 drift tube layers+ In-Plane alignment


Assembly Station


• Granite table: 6m x 2.5m

•Three bare Cross-Plates are positioned on the station, carried by sphere holders•The combs which will support the tubes are also visible•In the background: wiring station, Quality Control

setup(s)

Situation mid 99

North X

East Z

Up Y

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Chamber Assembly


• Spacer monitored by RASASSituation mid 2000

Sphere tower with changeable block to adapt to tube layers

NIKHEF Comb

Frascati comb

RASAStower

‘Ear’ with sphere and RASAS-MASK

In-plane mask

In-plane lens

Xplate

longbeam

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No Flexo


‘RASAS’ Monitors

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Monitor positioning during assembly by RASAS monitor:

Changeable blocks

Support ‘ear’ which holds the mask

The RASAS tower which holds the camera and lens

xplate

Block 1

Block 2

Block 3

Ypitch 26.011mm

Scatter 5um

Measured temperatures explain (small) drift


Temperature Stability

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•Aluminum expands 24um/ oC/m, Granite 7um/ oC/m

•Under normal conditions, temperature stable within +-0.4 oC

•Test case: increase temp. by 1 oC: check RASAS monitors

Xplate 2.4mfixed monitorgranite

Free toexpand

Raw: 50um

Correct for AL 24um/ oC/m

+ Correct for granite 7um/ oC/m


Tube Placing

Start with QC tubes

ProcedurePlace tubes on combs (Re-)Measure Wire FrequencyRun Final-OK programIF all tubes OK, follow placing scheme

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Glu Preparation

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Glu Preparation

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Glu Preparation

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Glu Preparation

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Glu Preparation

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Glu Preparation

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Glu Preparation

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Marcel Vreeswijk (NIKHEF) s

Tube diameter 3cmDistance 65m

tube

tube tube

tubetube

Side rope Central rope

Gluing (BOL-0)2 x glue units2x3 glue nozzles

•Tube layer 1 central ropes•Spacer glued on layer 1•Tube layer 2 central ropes•Spacer+1 glued on layer 2•Tube layer 3 central+side ropes•Spacer+1+2 on layer 3•etc….


Sag Compensation•

Sagcompen-sation tower

Additionalweight for balance

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•Own weight leads to large sag of xplates•Compensate (at Bessel points) with pneumatic system•Need typical P=3bar (8 towers) to carry chamber (150kg)

Residue:order 10m


Sag Compensation• Xplate sag before and after

compensation

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After sag adjustment we observe (almost) symmetric sags for chamber up and down positions-> no stress

Chamber up

Chamber (upside) down

Understoodwithin +-10m


The road to BOL-0BOL0bar S M N S M NL1 2.1 1.3 2.2 2.1 1.3 2L2 2.6 1.75 2.9 2.7 1.75 2.8L3 2.8 1.9 3.3 2.7 1.9 3.1L4 3.5 2.2 3.7 3.4 2.2 3.5L5 4.2 2.6 4.1 4.1 2.6 3.7L6 4.7 3.4 4.6 4.6 3.4 4.2

BOL0kg S M N S M NL1 26 16 25 53 65 50L2 34 22 35 68 88 70L3 34 24 39 68 95 78L4 43 28 44 85 110 88L5 51 33 46 103 130 93L6 58 43 53 115 170 105

BOL0kg S M N S M NL1 27 16 27 53 62 53L2 33 20 33 65 81 65L3 39 25 39 78 100 78L4 45 30 45 90 119 90L5 51 35 51 103 138 103L6 57 39 57 115 157 115

PRED./TOWER PRED./XP

BOTTLE GAUGE

FORCE/TOWER FORCE/XP


Gluing BOL-0

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Glue: Days needed1 Glue Spacer1 1st layer+platforms1 spacer on 1st1 2nd layer+spacer4 layersTotal <10 days


Gluing BOL-0• RASAS monitors

SE

NW

SW

NE

Global Z,RASAS X

Global X

•Stability in Y appears good

•Relatively large Z movement layer 6 (spacer floats on glue?)

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Lever arm in stacking block

Global Z

Global Y (up)


Gluing BOL-0• Guido laser test indicate tube

heights in combs <10um.

• Stability Xplates during gluing

Start glue

Start glue

Layer 2

Layer 3

Yrasnik=2 x Sag

Start glue

Layer 1

Layer 1: dSag=7um

Layer 2: dSag=10um

•The sag of the xplates in layer 1 and 2 change in time. Glue crimp? Temperature?•Layer 3,4,5,6: Sag stable

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The BOL-0

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The BOL-0 was mechanically

finished Dec 5th 2000

Next, studies:•X-ray scan


The road to BOL-0Date Item Comment1999 Cleanroom Prepare assembly stationApril 2000 Spacer Construct spacer

Nov. 2000 Setup ready Glue machine studies15/11 1st layer Gluing central ropes16/11 Platforms Problems with intrinsic

accuracy20/11 Spacer Spacer on 1st tube layer21/11 2nd layer Gluing central ropes22/11 Spacer Spacer+1st+2nd layer23/11 3rd layer First layer to layer;

problems with glumachine

24 –28/11 Glu machine Change CentralCilinders

29/11 4th layer Ok

1/12 5th layer Ok5/12 6th layer 20um Z shift

BOL0S M N S M N

L1 2.1 1.3 2.2 2.1 1.3 2L2 2.6 1.75 2.9 2.7 1.75 2.8L3 2.8 1.9 3.3 2.7 1.9 3.1L4 3.5 2.2 3.7 3.4 2.2 3.5L5 4.2 2.6 4.1 4.1 2.6 3.7L6 4.7 3.4 4.6 4.6 3.4 4.2

FLES BINNEN


The road to BOL-1Date Item Comment15/06 Glu Spacer Use sagcompensation26/06 Layer 1-half Problem glu-machine27/06 Layer 1-rest Ok27/06 Praxial Platforms No measurements…..

27/06 Spacer on 1st layer Ok28/06 Preparations29/06 2nd layer + spacer Spacer+1st+2nd layer ok01/07 Preparations02/07 Preparations03/07 3rd layer Spacer+3 layers ok04/07 4th layer Spacer+4 layers ok05/07 5th layer Spacer+5 layers ok06/07 Preparations09/07 6th layer Mechanically finishedJuly Gas manifolds +Protective covers>July Xray tomo@CERN>2001??? FE-Electronics

•From 1st tube layer to 6th tube layer took 14 days (spacer not counted)•With optimal/parallel preparation the present scheme would allow a 7 day production cycle•Infrastructure and manpower->

10 working-days/chamber


Test @CERN inTomograph


Test @CERN inTomograph

Wire positionsRMS 16m

Analysis of Martin Woudstra


Test stand

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DATCHADATCHA

Like cosmic ray setup at CERN (shutdown in 2000)

Test of alignment principle with prototype muon sector,using cosmic tracks --> 10m on sagitta


Test stand @NIKHEF

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Tests five chambers using cosmic rays (end 2001)•Checks wire positions•Checks DCS + DAQ

Trigger modules, consisting of 50cm iron, with two layers scintillator. Ecut>1GeVExpected rate: 100Hz


BOL-0Heat Studies (No flexoos in BOL-0)

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Inplane

Yrasnik= 2 x sag

The BOL-0 was covered with heat blankets, producing 50W/m2

Gradient between MLs: 2.5 to 4 oCSag of Chamber: 200um 50 to 80 um/oC= acceptableSag of xplate: 25um 6 to 10 um/oC = acceptable

400um

Yrasnik= 2 x sag

Xplate

50um

Chamber sag

Xplate

sag


Status and Plans

• Finished BOL-0 at NIKHEF (dec. 5th 2000) with high mechanical precision (16m RMS)

• Quality Control automated

• Production of tubes started May 2001

• Now: Produce first chamber

• Expect to finalize 10 chambers by end 2001

• Produce 1chamber/2weeks: 24 chambers/year -> finish summer 2005

• Late 2002, evaluate need to speed up chamber production (work weekends and/or two gluing steps/day)

• Cosmic ray setup operational end 2001


RASNIK• Components provided by NIKHEF

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Light source + maskImage sensor

Lens + holder


Precision Mechanics


• intrinsic accuracy better than 10um

The quantities which affect the wire positions are checked and found to be precise within 10umGranite table has sag of 25um + 10um light on/off

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Positioning combs and sphere holders Tools:

• Laser + optics (straightness combs),• silicon sensor (to line up combs),• Slof (height-meter), • tilt-meters (check Torque),• Balmonitor (dZ between multilayers)


Assembly Station


• The Balmonitor is a Cross-Plate equipped with lenses. Each lens is combined with a ‘fork’ on the combs to form a RASNIK system

•The Balmonitor measures the Z and Y difference between Sphere tower and Comb between North and South. (Z difference between Multilayers)

•Additionally the Balmonitor is used to check for height difference between sphere towers at the reference and non-reference side (West/East)

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Gluing BOL-0• Result for side (106) and central (103) ropes

Central rope

Central rope

Central rope

Central rope

Central rope,sometimes bad(stability glue unit?)

tube

The Assembly of ATLAS Muon chambers @NIKHEF

Documents

sthe bol

layer platforms1 spacer

um ocm tube placingstart

tube heights

rasas monitorsstability

central ropesspacer

expansion length o

large sag of xplatescompensate