Engineering (Mechanical)

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Engineering (Mechanical)

• Geoff Barber

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Contents

• Station assembly
• Tracker assembly
• Installation
• Patch-panel
• Installation procedure
• Infrastructure/Operation
• Gas system
• Helium/vacuum window
• Summary

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Station assembly

• We already have built four stations for a
  prototype tracker module
• We learned a lot from this experience as well as
  from the KEK test beam results
• We will incorporate quality assurance steps to
  station assembly procedure to eliminate source of
  problems for light-loss and fibre mapping
• In the following slides, station assembly
  procedure for the production of stations is
  explained step by step

4
Station assembly - sequence

• Receive doublet-layers from FNAL
• Visual inspection of the doublet-layers for any
  damage caused in transit
• Align the doublet-layers on a vacuum chuck
• Bundle seven fibres with rubber sleeves (QA)
• Thread the bundle into a station connector (QA)
• Put the vacuum chuck on an assembly jig
• Fix a carbon-fibre station to the assembly jig
• Glue the doublet-layers to carbon-fibre station
• Attach doublet-layers connectors to the
  carbon-fibre station
• Cut the fibres
• Pot the fibres
• Polish the fibres

5
Station assembly - tools

• Station holder
• Bundling Comb
• Connectorisation bridge
• Vacuum chuck
• Alignment jig

6
Station assembly - numbering

• Unique numbering scheme defined to make sure
  correct fibre mapping
• Start bundling from the centre fibre, marked
  during doublet-layer manufacturing
• QA procedure ensures correct bundling with comb

7
Station assembly - bundling

• Align doublet-layer on vacuum chuck
• comb to help identify error during bundling is
  being manufactured at Liverpool with aluminium
• Bundling procedure with comb will be
  established with the existing fibre ribbon

8
Station assembly - connector

• Bundle is threaded into the correct hole in the
  connector on bridge
• QA ensures correct threading procedure to be
  defined

QA gauge
View W 20 Way Bundles 1 20 To Bulkhead
Connectors 1, 6, 11, 16 21
1
5
3
4
2
6
8
10
7
9
11
13
12
14
15
16
Station connector Viewed from the polished
face. Internal light-guide connector viewed from
rear or fibre entry side.
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17
20
19
x
x
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Station assembly final steps
View of the station onto the polished face of the
connector

• Put the vacuum chuck on an assembly jig
• Fix a carbon-fibre station to the assembly jig
• Glue doublet-layer to carbon-fibre station
• Connectors on bridge is attached to the correct
  position
• Cut fibres
• Pot fibres
• Polish fibres

10
Station assembly - prototype
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Station assembly - summary

• We have built four stations. The fourth station
  design was improved by the experience gained
  during the three stations assembly.
• We have identified the source of problems to be
  fixed by the KEK test beamconnector hole
  alignment, fibre bundling and fibre
  connectorisation
• QA procedures will rectify the problems during
  station assembly, see Pauls talk
• We will build the fifth station with the improved
  assembly procedure which incorporates QA
• We will be ready to produce the stations soon.
• TODO
• Establish QA procedures with comb and bridge,
  see Pauls talk

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Tracker assembly

• We have built a tracker prototype with four
  stations
• Assembly scheme for the prototype will be used
  for the three production version of tracker
  modules with five stations
• Before starting assembly we need to fix the
  station spacing, see Malcolms talk

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Tracker assembly - space frame I

• Space frame between stations connects
• two stations together
• Barrel
• Gluing fillet
• Structural tube
• Locating foot
• Foot design
• improved from
• prototype

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Tracker assembly - space frame II

• These are the parts used for the prototype
• Close up view of the space frame
• feet and structural tubes

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Tracker assembly - jigs

• These are jigs used for the prototype assembly
• Jigs to be made after fixing station spacing
• Could be outsourced, the possibility will be
  investigated

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Tracker assembly - light-guide

• Channel map for station 1
• Length of the light-guide to be determined after
  fixing the station spacing

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Tracker assembly - prototype

• Four stations prototype without light-guides
• Equipped with light-guides
• We will build three more trackers one for spare

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Tracker assembly - summary

• We have built a tracker prototype with four
  stations
• Assembly tools and scheme for the prototype will
  be used for the production version
• TODO
• fix the station spacing, see Malcolms talk

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Installation

• We need to install the tracker module inside the
  bore of the solenoid module
• Damages to the tracker during the installation
  procedure should be prevented
• In the following slides, patch-panel and
  installation procedure is explained step by step

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Installation patch-panel

• Works as a fan-out for light-guides
• Gas-tight with O-ring to contain He
• 25 holes for fibre connectors
• 1 hole for hall probe field monitoring service

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Installation pp and diffuser

• The cover will need to be stiffened and tied back
  to the solid region where the patch-panel is
  mounted to the solenoid
• We have allowed a bore of 331Ø in the cover with
  a series of holes and a position for an O-ring
• Responsibilities allocated
• Need to finalise detailed design

Detail Drawing almost complete
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Installation pp ext. light-guide

• External light-guide makes one to one connections
  between the patch-panel connector and the VLPC
  128 way connectors.
• O-ring incorporated to ensure a gas seal
• Length of the external light-guide to be fixed
  with a full-size mock-up

Patch-panel connector
VLPC connector
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Installation Hall-probe mount

• Hall-probe can be fixed to a collar that will be
  attached to the bore of the solenoid
• Because we do not want to drill the bore we will
  fit the probes to an expanding collar that can be
  slid into the bore
• The position will be locked by means of a taper
  clamp to expand the collar
• Need to finalise detailed design

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Installation - sequence

• The following slides shows a first attempt of
  installation stages of the tracker into the
  solenoid
• Serve as a basis for a debate/discussion
• The installation procedure will be evolved by all
  interested parties
• It should be noted that all of this work will
  need to take place in a light-controlled
  environment, no ultra-violet light to avoid
  damage on scintillating fibres

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Installation - requirements

• To carry out the installation work we will need
  at least 2m of clear working area in front of the
  solenoid
• We hope that this is achievable either by
  removing equipment in front of the solenoid or as
  is more likely, by moving the solenoid sideways
  out of the beam line
• The solenoid and its kit would sit on a plinth
  and it would move as one
• As already stated we will need this area to be
  light controlled, this will probably be achieved
  by building a tent structure over the area
• We think this is better than having a lock
  mechanism for the lights in the MICE-hall, since
  other parties can work at the same time, less
  scheduling headache

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Installation stage 1

• The patch-panel is fitted and sealed to the
  solenoid
• Hope to test the seals using cover plates at this
  stage

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Installation stage 2

• Alignment jig is fitted into the bore of the
  solenoid
• feet are adjusted to set the cross hairs on the
  same axis as the solenoid bore
• azimuthal/z retaining bracket is fitted
• whole assembly surveyed
• The alignment jig works as a Go-gauge for the
  final installation

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Installation tracker adjustment

• PTFE foot, which rests on thebore of the
  solenoid, is eccentric
• PTFE foot can be rotated by turningthe green
  outer case that has a locating dog
• Once adjusted it can be lockedby turning the
  blue internal hex key

Views and sections of the adjustable PTFE foot
and its adjusting/locking tool
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Installation tracker positioning

• The tracker module sits on 4 adjustable feet two
  at the front, two at the rear
• The tracker module is held down by a sprint
  loaded foot at the 12 oclock position
• These foot aligns the axis of both tracker and
  solenoid
• The tracker module is aligned in z and azimuth
  by pulling a locating block into a Vee, which
  is located using dowels to the patch panel

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Installation stage 3

• The alignment jig is mounted onto the CMM in a
  jig that simulates the bore of the solenoid
• The alignment jig is surveyed
• CMM Computerised Measuring Machine

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Installation stage 4

• The tracker module is mounted on the same jig
• With the survey from the alignment jig, adjust
  the 4 support feet till the same axis as the
  alignment jig

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Installation stage 5

• The tracker module, complete with the light guide
  support structure, is lifted onto the
  installation cradle
• The light guide support structure is to ensure
  that no damaging forces are exerted on the fibres
• Covers will be fitted during transit

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Installation stage 6

• The tracker module is slid into its
  pre-determined position inside the bore of the
  solenoid
• The position will already have been determined
  using the target module

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Installation stage 7

• With the tracker in position and secured, the
  light guides can now be carefully re-routed to
  their final position in the patch panel.
• The gas-seal is fitted
• If the external light guides are not to be
  attached immediately then light tight/protection
  covers will remain fitted.
• The light-guides are secured.
• A shield will be fitted to stop any damage on
  light guides during diffuser installation
• When the diffuser is installed, the light guide
  support structure is removed
• If we are not ready to fit the diffuser
  mechanism then a cover plate will be attached

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Installation stage 8

• The patch-panel cover is installed and sealed to
  the patch-panel
• We can repeat the gas seal test at this point
• Now, installation finished!!
• Sequence designed, need to elaborate with all
  interested parties

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Infrastructure Land grab

• We need space for
• Cryocooler/Cryostat for VLPC read-out
• Two VME creates, local-DAQ computer, cabling
• He gas system for Cryo/Tracker pipes/cylinders
• Tent for installation 4 x 3 x 3 m3 (x, y, z)
  to be fixed with mock-up
• Because of the amount of equipment required to
  fit into the area and possible conflicts this may
  cause, it has been decided to build a 3D
  virtual model of the region
• We need to be sure that all of our fibres can be
  accommodated in the fibre length allowed, so this
  model will be the first step in this process
• We plan to build a full size mock-up of this
  region to convince ourselves that what we have
  designed is feasible
• The patch-panel, fibre run,trellis and VLPC
  unit have been modelled and the idea is (we hope)
  to ask Stephanie to assemble all of the 3D
  modelled items into a master model based on
  Tonys floor layout

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Infrastructure layout 1st attempt
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Infrastructure layout 2nd attempt

• This was an attempt to achievea shorter fibre
  run
• In 2D-model the longest run increased from 1884
  mm to 2200 mm
• Need to elaborate in 3D-modeland with a full
  size mock-up
• Activities initiated

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Infrastructure/Operation - Gas

• Maximum volume to be filled per
  trackerV(solenoid) pi0.422.735 1.38
  m3 (depends on window position)V(p-panel)
  pi0.85520.1/2 0.12 m3 (guess)V(total)
  1.5 m3 1500L
• To fill a tracker, 5 hours with flow rate of
  300L/hour
• In operation mode, 30L/hour? 7000L (60kg)
  cylinder every 9.7 days
• Needs- gas cylinder- pressure regulator-
  flowmeter- bubbler- supply/exhaust pipes-
  shutoff valve?- overpressure valve?
• He gas leaks from patch panel WILL NOT cause
  oxygen deficit. The MICE hall is ventilated

Exhaust to high release or outside
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Helium/vacuum window - study

• Chris Rogers study on aperture
• measure acceptance of MICE cooling channel in 2D
  phase space
• The detector and diffuser apertures should be at
  least large enough to transport these muons

Apertures m Apertures m Apertures m
Small LH2 RF Large LH2 RF Large LH2 Only
Diffuser z -6.011 0.14 0.18 0.19
Window 1 z-3.8 0.19 0.25 0.28
Window 2 Z3.8 0.24 0.29 0.29
Beam envelope
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Helium/vacuum window - design

• Decoupled from solenoid
• z-position will be adjusted to havesmaller beam
  envelope
• Make it thinner 0.5mm
• Effects of window will be studied with G4MICE

Top Hat
Top Hat cylindrical length machined to suit
position of the window
Radial distance of window curvature 360mm
Window to have 396mm OD
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Summary

• We will build fifth station to establish
  production line for the tracker
• As soon as doublet-layer becomes available,
  August
• Mechanical designs for station/tracker assembly
  almost complete
• Need to elaborate some details and require a
  final set of engineering drawings
• There is more work to be carried out on the
  installation/layout, helium/vacuum window, gas
  system
• Works initiated