#  NuMI-L-633 

#  May 8, 2000

**Far Detector Installation Procedures (WBS 2.4)**

## D. Ayres, W. Miller

Version 1.4

**Outline**

1.  Plane assembly summary chart

2.  Testing scintillator modules

3.  Steel plane assembly

-   Cable support brackets

-   Cleanup

4.  Magnet induction cables

5.  Scintillator installation

-   Cabling

-   Survey

-   Final Testing

6.  Plane mounting

-   Rig for lifting

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-   Lift Strongback

-   Move strongback down to detector face

-   Lower Strongback at workstation

### 

1.  **Plane Assembly Summary Chart**

![](media/image1.wmf)

The chart above is based on time and motion studies done during the 4PP
work at the New Muon Lab. The original TDR estimate was 24 hours/plane,
with 6.5 useful working hours per shift. The 3.5-hour difference between
the TDR and 4PP estimates will be added into the time contingency and
the original estimate of two planes every 3.7 shifts, or 5.4 planes per
week, will continue to be used.

2.  **Testing scintillator modules**

-   **Light leak test**

Each module must pass the light leak test before it can be mapped. All
light leaks must be repaired first. The module is removed from the
shipping box with the vacuum lifter and placed on the module mapper
table where all the repair work takes place. Data from the tests and
repair work done at the module factory (via database) are used to help
locate leaks and new leaks are entered. This database record will be
used to eliminate leaks recurring in the same locations. Light leaks are
fixed using black silicon and tape.

-   **Module mapping test**

The current estimate for module mapping time is about 1 hour per module,
including moving the module on to and off of the mapper table and
connecting it to the readout system, but not including repairs. The
radioactive ^60^Co source is automatically parked in a heavily shielded
"garage" on the mapper table when it is not in use. The two physicist
module testers do not have to be present during the 30-minute mapping
time. Once the mapper is started it runs on its own until completion.
Mapper data are automatically entered into the database. Physicists
perform the module testing with occasional rigging help from the
minecrew staff.

-   **Storage**

##### Once a module has passed its tests, it is raised through the lifting bay to the Soudan Mezzanine storage area and placed in a storage rack or in an installation crate. Installation crates are relatively expensive, so there are only a few (\~3) of them. Each installation crate is used to hold all the modules for a single plane, stacked in the order in which they will be installed on the plane. When an empty installation crate is returned from the workstations, it is refilled with tested modules from the storage racks. The order of modules from the bottom of the crate is 8,1,7,2,6,3,5,4. See figures 6 and 7 for module position number and installation sequence.

-   **Move to MINOS Hall**

Tested modules in their installation crate are lowered from the Soudan
Mezzanine storage area, using the 7 ½ ton overhead crane, onto
scintillator carts and rolled into the MINOS Hall via tunnel between
halls.

3.  **Steel plane assembly**

    1.  **First layer**

Plates for the first layer are pulled out of the steel storage cart
using plate clamps mounted on a spreader bar on the gantry crane. Plates
have been bundled in the surface building to ensure that they are in the
correct order and orientation. The plates must be positioned accurately
to minimize the gaps between them and to align the center hole and the
ears of neighboring planes. After the first plate is pushed up against
stops on the strongback, each subsequent plate is pulled into place
using a come-along or hydraulic spreader attached to pushing and pulling
points on the strongback. Once all 4 plates are in position the first
layer is inspected for burrs and other debris that could cause gaps
between steel layers. The first layer is carefully cleaned and the
plates for the second on layer are placed on top. All plates are
bar-coded for identification. Bar codes for plates in the first layer
must be entered into the database before the second layer is added. The
locations and widths of any gaps between plates that are larger than
about 1/16\" are also recorded in database.

> ![](media/image2.png){width="5.439583333333333in"
> height="5.185416666666667in"}.

Figure 1 shows positions steel plates in the bottom layer.

> **3.2 Second layer**

Repeat procedures as on the bottom layer. Sheet #1 goes on first and
must be carefully placed so it is against the bottom clips and the
stops. The next three sheets are set down. Care should be taken to try
to align the load bearing areas of the ears with the ears on the lower
layer.

![](media/image3.png){width="5.28125in" height="4.843055555555556in"}

Figure 2 shows position of top layer of steel plates.

> **3.3 Alignment**

If alignment in the ear area is not perfect, the protruding layer must
be ground flat in the area where it meets the rail. The alignment of the
holes between the two layers should be checked and adjusted (by
grinding) as necessary. The clearance of the upper plane clamps should
also be checked at this time.

4.  **Plug welding**

Use a heavy weight if needed to flatten plates while welding. Welding is
done in the pattern shown below, using a TIG welder supplied by the
steel task. A certified welder does all the plug welds with one of the 3
technicians on each workstation assisting. There is one welder for each
shift so his time is split between workstations. The welds should nearly
fill the holes. After the welds are completed and cooled, grind any
excess material so the welds are flush with the surface.

![](media/image4.wmf){width="4.978472222222222in"
height="4.615277777777778in"}

Figure 3 shows welding pattern designed to keep steel plates from
overheating.

**3.5 Cable support brackets**

While plug welds are being done the other 2 technicians mark the outside
edge of the plane, using the ears as starting points, for the placement
of the clear fiber cable supports. They also mark the placement location
for the first scintillator module. Figure 4 shows the cable support
locations. The supports are installed using a stud gun. Dimensions on
figure 4 are in inches. Figure 5 shows the location of the different
length brackets. They are installed before the first module is placed
down.

![](media/image5.png)

Figure 4 shows the locations of clear fiber cable support brackets.

![](media/image6.jpeg){width="5.793055555555555in"
height="5.793055555555555in"}

Figure 5 shows cable bracket lengths. This pattern is repeated

in each quadrant needing cable support.

6.  **Survey targets**

Survey lugs are welded to the steel as references for the survey
measurements of module positions. A total of 6 survey lugs are welded to
the outsides of planes 1, 2, and 3. They are placed at the positions
shown in figure 5 on all planes. Care must be given during clear fiber
installation that these locations are kept clear so that the surveyors
have a clear view of the targets after the planes are intalled on the
support structure.

> ![](media/image7.png){width="4.507638888888889in"
> height="4.317361111111111in"}

Figure 5 shows the locations of the external survey points.

> **3.7 Cleanup**

Check for burrs on the upper layer of steel and grind off. Clean steel
plane of all debris, inspect the plane and note positions and widths of
any gaps larger than about 1/16\".

4.  **Magnet induction cables**

**The components:**

The coils will be pre-made, tested, and shipped to the mine, as will the
connector boards. (There is one board for each coil but they are
completely interchangeable.) Each of these boards will have a single
twisted-pair cable running to a PC readout board.

The PCs will be in the auxiliary mid-level "racks" (i.e., not in the VME
or HV racks). These may not really be racks if our PCs are the only
things there. 128 twisted pairs will run to each PC/expansion box. There
will be 1 or 2 PCs in each location on each side of the detector.

The ribbon cables do not need to be labeled. The boards will be labeled
but they are interchangeable. The board locations should be logged
(plane, location). At least initially the twisted pairs cables will be
made and labeled in place.

Proposed labeling format: B.###.f.@@ where:

-   \### is the plane number

-   f is the detector face (1 to 8, 1 is the east horizontal, 2 is the
    upper east 45, 3 is up, \...)

-   @@ is the PC number (numbering yet to be determined).

**Deployment details:**

Most planes have one induction coil running horizontally to the east.
The coil ends come out at the middle-deck level. The twisted pairs will
run from the boards hanging on the plane north or south to the read out
PCs on the mid-level deck (in the cable tray?).

There will be 6 cables each on the first 10 and the last 10 planes of
each SM. There will also be 6 cables each on 5 (or 10) additional planes
in each SM. The latter planes will be fairly evenly spaced and chosen to
sample different heats of steel. The selection of planes will be worked
out in with the installation group as installation progresses.

In the planes with 6 coils, 3 will follow the optical cables to the east
vertical face and 3 will run to the west. On each side, 2 of the
connector boards will be "in the air" around the plane. The twisted
pairs will run around the circumference to the mid-level deck.

**Installation plan:**

**Before the modules are installed:**

The ribbon cables will come pre-tested and rolled. At the collar
location they will be pre-folded. Over the rest of the length they can
be flat.

The locations for the coils will be cleaned with alcohol to get good
tape adhesion.

The ID and OD of the steel, where the cables will pass, will be taped
with Kapton.

The cables will be half unrolled, the folded section will be positioned
at the bore. The cable is then taped onto the steel (\~1 ft intervals)
with Kapton along its 4 m length.

The remaining (still rolled) cable is put through the bore. It will be
temporarily secured until after the plane is erected.

**Before the lift:**

For planes with 6 induction cables, the top, bottom, and two 45 faces
will have their connector board attached to the half of the cables that
is visible. A long length (30 m) of twisted pair (with only one
connector attached) is labeled, connected to the connector board, tied
to the support brackets, and routed to the east (or west) vertical face.
These are near the "I" supports shown in figure 5.

If there is only 1 coil nothing needs to be done at this stage.

**After the strongback is released and the manlift is in place to access
to the bolts/collar:**

After the bolts are in place and before the collar is installed, the
surface of the steel is cleaned for good adhesion. The "outside" halves
of the cables are unrolled a few feet and taped into place. The collar
is brought into position and the cables are adjusted to ensure that the
collar does not crush them.

After the collar is in place the man lift is worked across the face to
the detector and the cables are taped in place.

The connector board is attached and the coil's resistance is measured
using a DVM. If it is acceptable (in the 4PP it was 80 ohms ±10%) then
the cable and board are good. If a coil shows an open circuit and cannot
be repaired, its condition is logged and it will not be used. If coil
resistance is a few ohms then there is a problem with connector
orientation or a short (e.g., damage at the collar).

**Cabling/commissioning:**

Connect a twisted pair cable to the connector board and route it to the
PC. Cut the length (\~3 ft spare) and leave it labeled. Strip the
conductor back ¼" and test the resistance again.

There are screw-in terminals on the readout boards. The wiring/terminal
locations will be specified in advance. Log the cable and the terminal
numbers.

5.  **Scintillator installation**

    1.  **Modules placement and order**

Scintillator modules are oriented differently on odd- and even-numbered
planes. Figure 6 shows the order in which modules are welded and figure
7 shows the module position numbers. The installation procedure is as
follows:

Measure and snap a chalk line on centerline of the steel.

Move the modules with the vacuum-lifting fixture. Align the first
module, position #4, so that its marked centerline matches up with the
chalk line (or with the crack between the second and third plates of the
upper layer of steel, depending on the scintillator orientation). It is
critical that this one is in the proper location as all other modules
key off it. Make sure the bypass hole is lined up so that a collar can
be fitted inside the bypass. Modules are placed into position one at a
time and their H-clips are welded. Make sure the modules are pushed as
close to their neighbors as possible to ensure there is enough space to
weld the outermost H-clips.

**The ends of the modules, especially the optical connectors, are very
fragile. Do not step directly on the modules. When it is necessary to
walk on the modules, e.g., to position a new module, use large pieces of
rigid foam to spread the load. Keep walking on modules to a minimum.**

  -------------------------------------- --------------------------------
  Installation\                          Module\
  Order                                  Position

  4                                      X4

  5                                      X5

  3                                      X6

  6                                      X7

  2                                      X8

  7                                      X3

  1                                      X2

  8                                      X1
  -------------------------------------- --------------------------------

Figure 6 shows the module installation order.

> ![](media/image8.wmf)

Figure 7 module position numbers

> **5.2 Welding H-Clips**

Weld all H-clips to the steel plane using the 1/4\" holes on the clips
for the weld points. The first module has clips on both sides, but the
other seven have clips only along one edge. H-clips may have to be
spread slightly to allow the next module to be inserted after welding.
(A modification of the H-clip design to fix this problem is under
consideration.) To ensure that the H-clips are tight against the steel,
one of the techs holds down each clip while it is being welded. Care
must be taken not to heat up the scintillator module.

3.  **Cabling**

    1.  **Clear fibers cables**

The clear fiber cables used to connect the scintillator modules to the
MUX boxes are made up of either 20 or 28 individual 1.2-mm fibers. Each
fiber bundle is contained in a flexible, opaque, fire-resistant plastic
conduit with a diameter of 0.56 inches. A 5-inch long rigid plastic
shroud connects the fiber conduit to the connector on each end. **A
minimum bend radius of 12 cm must be maintained at all times during the
handling, installation, and routing of the cable conduits.** The cables
have two labels at each end -- one indicating the cable length in
meters, and the other a containing a unique cable identifier. The cables
will have been fully tested for light integrity and attenuation length
prior to shipment to the far detector site. The cables will be re-tested
as part of the module testing procedure, conducted before the plane is
raised to the vertical position. The cable mounting proceeds through the
following steps:

> 1\. The crate containing the cables for the plane under assembly is
> opened.
>
> 2\. The face of the module-side connector is coated with the optical
> couplant.
>
> 3\. The light seal gasket is slid onto the module connector.
>
> 4\. The cable connector is screwed to the module connector.
>
> 5\. The cable is unrolled and tied to the appropriate tie points with
> loose cable ties.
>
> 6\. Light seal and transmittance tests are conducted on the
> module/cable combination.

It is very important that brackets provide adequate strain relief so
that cables, connectors and module manifolds are not stressed. During
installation the bend radius restrictions must be strictly observed and
the cables must be handled very carefully. Considerable attention will
be required from the installation supervisors to prevent damage to the
optical fibers, connectors and manifolds.

Cables must be kept out of the stay-clear zones to maintain necessary
clearance while the strongback and plane are moved to the detector
support. The most important restriction is that the fibers and brackets
cannot extend more than 20 cm beyond the vertical edges of the plane.
The stay-clear zones are indicated in figure 8.

![](media/image9.png)

Figure 8 shows stay-clear zones for clear fiber and pulser cables on a
plane.

**5.3.2 Pulser fibers**

Pulser fibers are also installed while the plane is in the horizontal
position, after the readout cables have been strung. The cables are
carefully rolled out and cable-tied to the existing brackets. The
non-connector end is slipped into the light pulsing ashtray located in
the manifold. Black silicon is used to ensure light tightness.

**5.4 Survey**

The detector-plane survey can begin while final testing is underway. A
physicist is responsible for operating the total station survey
instrument. This device uses a laser to point to the spot whose location
is to be recorded, employing a simple point-and-shoot technique. Two
LEICA TC307 devices will be purchased by the installation task. The
Fermilab survey group has run a first set of tests and will do a full
trail run during the second 4PP assembly in late summer 2000. The
Fermilab survey group will train the minecrew personnel who will be
running the equipment. Module locations will be surveyed concurrently
with the final testing of each completed plane.

**5.5 Final completed plane testing**

This is the last chance to repair or record any problems on the plane.
Once it is in the detector the scintillator plane will be buried and
only the connectors and outer parts of the manifolds are accessible. It
is important that everything is checked and double-checked because this
is the last chance to make repairs on the scintillator plane.

5.5.1 **Light Leaks**

This is a very important test because once the plane is in place you
can't get in to fix light leaks. The stand-alone test equipment is being
supplied by the scintillator task. The final versions of the test
equipment will be tried during the second 4PP work at Fermilab during
summer 2000. This test checks all clear fiber cable connections as well
as the WLS fiber inside the modules. Repairs are made using black
silicon and tape. All repairs and tests are recorded in the database for
future reference.

2.  **Pulser test**

This is a stand-alone system test used just for checking completed
planes. It is performed in conjunction with the light leak test
equipment and checks to make sure that all fibers and connectors
transmit signals. This test equipment is supplied by the scintillator
task. All tests and repairs are recorded in the database.

3.  **Rig for lifting**

##### All strongback clamps are engaged and checked before the scintillator modules are installed. After all system checks have been completed and plane is ready for deployment, it is prepared for lifting. Spreader bar and crane are positioned and attached to the strongback. Before the strongback can be lifted all workers at both workstations must move away. They can't come back into the lifting area until the strongback is totally clear. This lifting procedure takes 3-5 minutes, in addition to the time it takes to move the plane to the detector area. 

6.  **Plane mounting**

**6.1 Lift Strongback**

The lifting sequence requires very little movement of the crane. The
non-lifting side of the strongback has Hilman rollers that support the
bottom edge of the strongback. It rolls toward the crane until the plane
is vertical. Once it is suspended from the crane it can be raised high
enough to clear the second strongback (if needed) and can move towards
the detector face.

**6.2 Move strongback down to detector face**

The crane moves the strongback very slowly between the sides of the
narrow support structure. There is only 20 cm of clearance on each side.
Very little side-to-side swinging motion can be allowed as it moves to
the detector face without damaging scintillator modules or detector
hair. The workstation crew that completed the plane is also in charge of
spotting the plane as it moves to the detector face.

**6.3 Position**

The last few inches before the detector face are very critical because
the strongback is tilted slightly to keep the completed plane in place.
This means that the bottom of the strongback hits the detector face
before the top is in position. If needed, a pusher block can be
installed on the support rail and a hydraulic jack can be used to nudge
it in the last few inches. The axial rod bolts and coil collars have
very little room for play. It is possible that a shim may have to be put
on one or both rails to help position the plane. Once the plane is in
position (the strongback is still attached to the plane) it is ready to
have its axial rod bolts installed. While some technicians install the
bolts, the remaining members of the workstation crew clean the
workstation area for the next plane.

**6.4 Install axial rod bolts**

The axial rod bolts have a preset collar that sets the spacing on the
planes. After each plane has been mounted it is surveyed to make sure it
is plumb. If the planes are out of alignment, small shims are added or
the axial rod collars are machined. The four axial rod bolts on the
sides of a plane are installed first. Then the strongback is removed and
the two top bolts are installed using the access bridge. The two bottom
bolts are installed last.

**6.5 Release strongback and return to workstation**

The 4 strongback clamps are released now that the plane is secured and
the strongback is slowly lowered until the bottom support ledge is clear
of the plane. Then the strongback is moved slowly towards the
workstation. Because the weight of the plane has been removed from the
lifting fixture, the center of gravity has changed considerably. The
strongback will hang several degrees from plumb. This gives additional
clearance during the strongback lowering process. As in the lifting
stage, when the strongback is overhead all workers must clear the area.

**6.6 Lowering Strongback at workstation**

This is one of the trickier moves with the strongback. It is very
important to pull the bottom of the strongback away from the crane with
sufficient force to make sure the strongback can't flip over. Once the
weight is on the Hilman rollers the crane can be slowly lowered. When
the strongback is back on the floor the spreader bar and crane can be
removed.

**6.7 Complete installation of axial rod bolts and collar**

When the strongback is out of the way, the top and bottom axial rod
bolts and coil collar are installed. The top axial rod bolts are reached
by the detector access bridge. The center coil collar is reached by a
manlift. The induction coils are unrolled and attached to the exposed
face of the plane, using the manlift, at this time as well. Care must be
taken to ensure that the coil collars line up perfectly with preceding
planes. Collars must be adjusted, using a special insertion jig, to
eliminate ridges and ensure a straight channel for insertion of the
cooling coil when the supermodule is completed. The collar is installed
as follows:

-   Insert the jig into the bore, extending a few inches beyond the
    collar on the previous plane.

-   Place the collar for the new plane on the jig.

-   Slide the new collar into place, taking care not to damage the
    induction coil(s).

-   Insert the collar bolts loosely but do not tighten.

-   Shim the collar using tapered pins.

-   Tighten the collar bolts.

-   Remove the insertion jig.

-   Check the collar alignment and repeat alignment procedure if
    necessary.

**The plane is now ready to be hooked up for readout. It can still
removed for repair until the next plane is mounted.**