Engineering (Mechanical)
Geoff Barber
Takashi Matsushita
t.matsushita@imperial.ac.uk
Imperial College
T. Matsushita 1
Contents
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Station assembly
Tracker assembly
Installation
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Patch-panel
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Installation procedure
Infrastructure/Operation
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Gas system
Helium/vacuum window
Summary
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Station assembly
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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
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Station assembly - sequence
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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
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Station assembly - tools
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Station holder
Bundling Comb
Connectorisation bridge
Vacuum chuck
Alignment jig
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Station assembly - numbering
Centre Fibre
Channel 214
Channel 108
Channel 107
Channel 1
Mylar
Chuck with numbering for planes ‘V’ & ‘W’
View from end of chuck looking at the connector end of the fibre ribbon
Centre Fibre
Channel 212
Channel 107
Channel 106
Channel 1
Mylar
Chuck with numbering for planes ‘X’
View from end of chuck looking at the connector end of the fibre ribbon
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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”
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Station assembly - bundling
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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
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Station assembly - connector
Bundle is threaded into the correct hole in the connector on “bridge”
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QA ensures correct threading; procedure to be defined
QA gauge
View ‘W’
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20 Way
Bundles
1 – 20
1
5
To Bulkhead
Connectors
1, 6, 11, 16 & 21
Station connector
Viewed from the
polished face.
Internal light-guide
connector viewed
from rear or fibre
entry side.
4
2
3
10
9
8
7
6
16
15
14
13
12
11
19
20
x
18
17
x
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Station assembly – final steps
View of the station onto the polished face of the connector
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Put the vacuum chuck on an
assembly jig
Fix a carbon-fibre station to
the assembly jig
Glue doublet-layer to carbonfibre station
Connectors on “bridge” is
attached to the correct
position
Cut fibres
Pot fibres
Polish fibres
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Station assembly - prototype
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Station assembly - summary
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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 beam;
connector hole alignment, fibre bundling and fibre connectorisation
QA procedures will rectify the problems during station assembly, see Paul’s
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:
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Establish QA procedures with “comb” and “bridge”, see Paul’s talk
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Tracker assembly
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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 Malcolm’s
talk
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Tracker assembly - space frame I
Space frame between stations connects
two stations together
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Barrel
Gluing fillet
Structural tube
Locating foot
Foot design
improved from
prototype
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Tracker assembly - space frame II
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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
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These are jigs used for the prototype assembly
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Jigs to be made after fixing station spacing
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Could be outsourced, the possibility will be investigated
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Tracker assembly - light-guide
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Channel map for station 1
C1
1 to 20
C2
21 to 42
C3
43 to 64
Bulkhead 1
C4
65 to 86
1 to 128
C5
87 to 108
C6 109 to 128
Length = XXXmm
C7 129 to 148
C8 149 to 170
C9 171 to 192
Bulkhead 2
C10 193 to 214
129 to 256
C11 215 to 236
C12 237 to 256
Length = XXXmm
Station end
Patch-panel end
C13 257 to 276
C14 277 to 298
C15 299 to 320
Bulkhead 3
C16 321 to 342
257 to 384
C17 343 to 364
C18 365 to 384
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Length = XXXmm
Length of the light-guide to be determined after fixing the station spacing
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Tracker assembly - prototype
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Four stations prototype without light-guides
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Equipped with light-guides
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We will build three more trackers; one for spare
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Tracker assembly - summary
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We have built a tracker prototype with four stations
Assembly tools and scheme for the prototype will be used for the production
version
TODO:
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fix the station spacing, see Malcolm’s talk
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Installation
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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
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Works as a fan-out for light-guides
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Gas-tight with O-ring to contain He
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25 holes for fibre connectors
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1 hole for hall probe field monitoring service
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Installation – pp and diffuser
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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
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Responsibilities allocated
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Need to finalise detailed design
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Installation – pp & ext. light-guide
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External light-guide makes one to one connections between the patch-panel
connector and the VLPC 128 way connectors.
Patch-panel
connector
VLPC
connector
O-ring incorporated to ensure a gas seal
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Length of the external light-guide to be fixed with a full-size mock-up
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Installation – Hall-probe mount
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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
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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 “lightcontrolled” environment, no ultra-violet
light to avoid damage on scintillating
fibres
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Installation - requirements
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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
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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
1.
2.
3.
4.
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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
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PTFE foot, which rests on the
bore of the solenoid, is eccentric
PTFE foot can be rotated by turning
the “green” outer case that has a
locating dog
Once adjusted it can be locked
by 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
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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 o’clock
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
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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
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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
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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
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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
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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
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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
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If we are not ready to fit the diffuser
mechanism then a cover plate will
be attached
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Installation – stage 8
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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!!
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Sequence designed, need to elaborate with all interested parties
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Infrastructure – Land grab
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We need space for;
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Cryocooler/Cryostat for VLPC read-out
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Two VME creates, local-DAQ computer, cabling
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He gas system for Cryo/Tracker; pipes/cylinders
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Tent for installation 4 x 3 x 3 m**3 (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 Tony’s floor layout
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Infrastructure – layout 1st attempt
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Infrastructure – layout 2nd attempt
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This was an attempt to achieve
a shorter fibre run
In 2D-model the longest run
increased from 1884 mm to
2200 mm
Need to elaborate in 3D-model
and with a full size mock-up
Activities initiated
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Infrastructure/Operation - Gas
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Maximum volume to be filled per tracker;
V(solenoid) = pi*0.4**2*2.735
= 1.38 m**3 (depends on window position)
V(p-panel) = pi*0.855**2*0.1/2 = 0.12 m**3 (guess)
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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
V(total) = 1.5 m**3 = 1500L
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To fill a tracker, 5 hours with flow rate of 300L/hour
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In operation mode, 30L/hour?; 7000L (60kg) cylinder every 9.7 days
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Helium/vacuum window - study
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Chris Roger’s 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
Beam envelope
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
Z~+3.8
0.24
0.29
0.29
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Helium/vacuum window - design
Top Hat cylindrical length
machined to suit position of
the window
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Decoupled from solenoid
z-position will be adjusted to have
smaller beam envelope
Radial distance of window
curvature = 360mm
Top Hat
Make it thinner; 0.5mm
Effects of window will be studied
with G4MICE
Window to have 396mm OD
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Summary
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We will build fifth station to establish production line for the tracker
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As soon as doublet-layer becomes available, August
Mechanical designs for station/tracker assembly almost complete
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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
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Works initiated
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