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  ![](media/image1.wmf){width="0.9326388888888889in"   Pixel Local Supports                     
  height="0.975in"}                                    FDR                                      

  ATLAS Project Document No:                           Institute Document No.  Created :        Page: **1
                                                                               **26/05/2000**   of** **10**

  ATL-IP-FR-0001                                                               Modified :       Rev. No .:
                                                                               **     **        **1**
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+-----------------------+-----------------------+-----------------------+
| ATLAS DISK SECTOR     |                       |                       |
| FABRICATION AND       |                       |                       |
| SPECIFICATIONS        |                       |                       |
|                       |                       |                       |
| The fabrication       |                       |                       |
| procedures for Pixel  |                       |                       |
| Disk Sectors are      |                       |                       |
| presented.            |                       |                       |
+-----------------------+-----------------------+-----------------------+
| Prepared by:          | Checked by:           | Approved by:          |
|                       |                       |                       |
| E. Anderssen, M.      |                       |                       |
| Gilchriese,           |                       |                       |
|                       |                       |                       |
| W.K. Miller, D. Uken, |                       |                       |
| J. Wirth              |                       |                       |
+-----------------------+-----------------------+-----------------------+
| Distribution List     |                       |                       |
|                       |                       |                       |
|                       |                       |                       |
+-----------------------+-----------------------+-----------------------+

  --------- --------- --------- -----------------------------------------
  History                       
  of                            
  Changes                       

  Rev. No.  Date      Pages     Description of changes

                                     
  --------- --------- --------- -----------------------------------------

Table of Contents

1 Introduction [4](#introduction)

2 Aluminum-tube Sector [4](#aluminum-tube-sector)

2.1 Aluminum Tube [4](#aluminum-tube-strain-relief-and-tube-connections)

2.2 Carbon-carbon Facesheets [4](#carbon-carbon-facesheets)

2.3 RVC Foam [5](#rvc-foam)

2.4 Bond 1st Facesheet to Foam [5](#bond-1st-facesheet-to-foam)

~~2.5~~ ~~Bond~~ Prepare 2nd Facesheet a~~nd Hard Points~~ for bonding
[5](#prepare-2nd-facesheet-for-bonding)

2.6 Apply CGL with 75µ Glass Beads to Tube
[6](#apply-cgl-with-75µ-glass-beads-to-tube)

2.7 Final Assembly [6](#final-assembly)

2.8 Quality Control [7](#quality-control)

3 Appendix A: Carbon-Carbon Sheet Specification
[8](#appendix-a-carbon-carbon-sheet-specification)

4 Appendix B - Reticulated Vitreous Carbon Foam Specification
[8](#appendix-b---reticulated-vitreous-carbon-foam-specification)

5 Appendix C - Aluminum Tube Specification
[8](#appendix-c---aluminum-tube-specification)

6 Appendix D - Drawings of Aluminum-Tube Sector
[8](#appendix-d---drawings-of-aluminum-tube-sector)

# Introduction

This note describes the fabrication sequence of the ATLAS Pixel Disk
Sector. This sequence is still under development and not all steps are
specified here. The fabrication of both aluminum-tube and
sealed-carbon-carbon-tube sectors are described. QC measurements for the
aluminum-tube sector are summarized in a Table in this note. Key
materials specifications are provided in Appendices.

# Aluminum-tube Sector

## Aluminum Tube, Strain Relief and Tube Connections

3003 aluminum tubes to be supplied in \"O\" condition.

Measure tube length(record)

Weigh tube(record)

Store in freezer @ -40ºC until preparing for bending.

Fill with wax by gravity in 65ºC oven. Oven cool.

Bend-flatten-rebend as required (bending fixture) (flattening fixture)

Inspect\_ go no-go gage & visual

Remove most filler wax by submerging in 70ºC water

Remove remaining wax by submerging in lamp oil at 50ºC (4hrs minimum)

Ultrasonic clean tubes in \'Blue Gold\'. Rinse with D.I. water

Weigh tube again (should be same as first) (record)

Cut the tube to length (fixture)

Weigh cut tube (record)

UHV clean square to round tube end transition pieces

Weigh, (record)

UHV clean PEEK tube strain relief pieces

Weigh, (record)

Use Hysol EA9396 to bond tube end transition and strain relief pieces to
cut tube (fixture)

Inspect\_ go no-go gage & visual (record)

Weigh assembly (record)

Pressurize to 10 bar (in fixture) (record)

Cap and mask both tube ends

Mount in anodize fixture

UHV clean followed by phosphoric acid. anodize (still need to spec.
procedure)

Remove plugs and any remaining masking from both tube ends

Weigh tube (record)

Leak test (record)

Store in individual boxes with documentation (flat file)

## Carbon-carbon Facesheets

Inspect raw materials flatness thickness weight @ ºC and %RH (record)

Cut profile and alignment holes on mill (vacuum fixture)

Inspect (Go, No-Go gage) (record)

Ultrasonic clean then bake dry (121ºC 1hr)

Store in individual boxes with documentation (flat file)

## RVC Foam

Inspect raw materials flatness thickness weight @ ºC and %RH (record)

Rough-cut the outer perimeter of foam

Face both sides holding the foam with two sided tape on mylar sheet
which is in turn, held by a vacuum chuck on a vertical mill

Ultrasonic clean then bake dry (121ºC 1hr)

Store in individual boxes with documentation (flat file)

## Bond 1st Facesheet to Foam

The outer release sheet of the cyanate ester film will be cut to shape
with a film cutter

The release sheet/ester sections representing the tube profile and
mounting spacers will be removed prior to application to the facesheet

Weigh the Facesheet @ ºC and %RH (record)

Apply cyanate ester to the inside surface of the facesheet just prior to
bonding with reticulated vitreous carbon foam. (position with alignment
fixture) chill, remove paper backing, set aside in a protected location
to allow condensed moisture to evaporate from facesheet/cyanate ester

Weigh @ ºC and %RH with cyanate ester (record)

Rough position foam on facesheet w/cyanate ester

Place assembly between flat plates w/spacers

Bake @ 250ºC for 3 hrs

Mount assembly onto vacuum fixture in NC mill face to thickness, cut
tube slot and clear foam from mounting holes.

Inspect\_ go no-go gage & visual (record)

Ultrasonic clean then bake dry (121ºC 1hr)

Weigh @ ºC and %RH (record)

## Bonding of Hard Points

Carbon-carbon hard points to be inspected, UHV cleaned and baked dry

Select a set for one sector

Weigh @ ºC and %RH (record)

Position mold released hard point bonding jig on the above facesheet.

(essentially a mockup of the tube with hard point alignment marks that
fits into the foam.

Apply Hysol EA9396 to one surface of each hard point and the
corresponding surface on the facesheet

Position each hard point on facesheet next to the appropriate alignment
marks on the bonding jig

Cure overnight

Remove bonding jig

Weigh assembly @ ºC and %RH (record)

Inspect hard point height with a captive micrometer (record)

Store in individual boxes with documentation (flat file)

## Prepare 2nd Facesheet for Bonding

Weigh the Facesheet @ ºC and %RH (record)

Apply cyanate ester just prior to bonding with reticulated vitreous
carbon foam. (position cyanate ester with alignment fixture) chill,
remove paper backing, protect and set aside to allow condensed moisture
to evaporate from facesheet/cyanate ester

Record weight @ ºC and %RH with cyanate ester

## Apply CGL with 75µ Glass Beads to Tube

CGL 7018 to be supplied premixed with 3% 75µ glass beads

Fixture tube assembly for CGL application

Tare tube and fixture (record)

Apply CGL to 1st side of tube (CNC stage)

Weigh tube and fixture (record)

Apply CGL to 2nd side of tube (CNC stage)

Weigh tube and fixture (record)

Position 1st facesheet against stops on base of mold released bonding
fixture.

Use pins through strain relief tabs to align the cooling tube with CGL
onto the facesheet

Position 2nd facesheet against stops on top of the 1st.

position clamping plate on top of the assembly

Fasten both sides of bonding fixture together

Inspect for proper fit

Bake @ 80 ºC for 16 hrs then 250 ºC for 3 hrs

Remove the assembly from the bonding fixture

Record weight @ ºC and %RH

Inspect for flatness thickness and parallel sides

Place sector on milling fixture to take skim cut on spacer washers

Final inspection

## Final Assembly

Mount targets for survey

Seal foam

Clean

Inspect, weigh and record

Survey via optical CMM and record locations of targets relative to
mounting buttons

## Quality Control 

A preliminary summary of quality control items is given in the table
below. All length units are mm. All weights are in grams.

+-----------------------------------+-----------------------------------+
| ##### Item {#item .unnumbered}    | **Measurement/Inspection**        |
+-----------------------------------+-----------------------------------+
| ##### Aluminum T                  |                                   |
| ubes and Connections {#aluminum-t |                                   |
| ubes-and-connections .unnumbered} |                                   |
+-----------------------------------+-----------------------------------+
| Length after initial cutting      |                                   |
+-----------------------------------+-----------------------------------+
| Weight after initial cutting      |                                   |
+-----------------------------------+-----------------------------------+
| Inspect after annealing           |                                   |
+-----------------------------------+-----------------------------------+
| Go/no-go and inspect after        |                                   |
| bend/flatten                      |                                   |
+-----------------------------------+-----------------------------------+
| Weight after bending              |                                   |
+-----------------------------------+-----------------------------------+
| Weight with plugged ends for      |                                   |
| anodizing                         |                                   |
+-----------------------------------+-----------------------------------+
| Weigh after anodizing             |                                   |
+-----------------------------------+-----------------------------------+
| Weight after cutting to length    |                                   |
+-----------------------------------+-----------------------------------+
| Weigh square-to-round pieces      |                                   |
+-----------------------------------+-----------------------------------+
| Weigh PEEK strain relief pieces   |                                   |
+-----------------------------------+-----------------------------------+
| Weigh tube/connection assembly    |                                   |
+-----------------------------------+-----------------------------------+
| Leak/pressure test                |                                   |
+-----------------------------------+-----------------------------------+
| Visual inspection/label           |                                   |
+-----------------------------------+-----------------------------------+
| ####                              |                                   |
| # Carbon-carbon Faceplates {#carb |                                   |
| on-carbon-faceplates .unnumbered} |                                   |
+-----------------------------------+-----------------------------------+
| ##### Inspect raw plates          |                                   |
| {#inspect-raw-plates .unnumbered} |                                   |
+-----------------------------------+-----------------------------------+
| Go/no go after cutting faceplates |                                   |
+-----------------------------------+-----------------------------------+
| Weigh faceplates                  |                                   |
+-----------------------------------+-----------------------------------+
| ##### R                           |                                   |
| VC Foam {#rvc-foam-1 .unnumbered} |                                   |
+-----------------------------------+-----------------------------------+
| Inspect raw materials             |                                   |
+-----------------------------------+-----------------------------------+
| Determine density                 |                                   |
+-----------------------------------+-----------------------------------+
| Bond 1st Faceplates to Foam       |                                   |
+-----------------------------------+-----------------------------------+
| Weigh faceplate with cyanate      |                                   |
| ester                             |                                   |
+-----------------------------------+-----------------------------------+
| Inspect after cutting foam        |                                   |
+-----------------------------------+-----------------------------------+
| Weigh after cutting foam          |                                   |
+-----------------------------------+-----------------------------------+
| ##### CGL+Glass Be                |                                   |
| ads {#cglglass-beads .unnumbered} |                                   |
+-----------------------------------+-----------------------------------+
| Weigh tube in fixture             |                                   |
+-----------------------------------+-----------------------------------+
| Weigh tube and fixture after CGL  |                                   |
| applied side 1                    |                                   |
+-----------------------------------+-----------------------------------+
| Weigh tube and fixture after CGL  |                                   |
| applied side 2                    |                                   |
+-----------------------------------+-----------------------------------+
| ##### Bond 2nd Faceplates         |                                   |
| and Hard Points {#bond-2nd-facepl |                                   |
| ates-and-hard-points .unnumbered} |                                   |
+-----------------------------------+-----------------------------------+
| Weigh 2nd faceplate with cyanate  |                                   |
| ester                             |                                   |
+-----------------------------------+-----------------------------------+
| Weigh hard points, spacers and    |                                   |
| washers                           |                                   |
+-----------------------------------+-----------------------------------+
| Weigh after heat cure             |                                   |
+-----------------------------------+-----------------------------------+
| Inspect for thickness             |                                   |
+-----------------------------------+-----------------------------------+
| Inspect for planarity             |                                   |
+-----------------------------------+-----------------------------------+
| Visual inspection after face cut  |                                   |
| mounting buttons                  |                                   |
+-----------------------------------+-----------------------------------+
| Final Assembly                    |                                   |
+-----------------------------------+-----------------------------------+
| Inspect after mounting targets    |                                   |
| and sealing foam                  |                                   |
+-----------------------------------+-----------------------------------+
| Weigh after final cleaning        |                                   |
+-----------------------------------+-----------------------------------+
| Survey targets/reference mounting |                                   |
| buttons                           |                                   |
+-----------------------------------+-----------------------------------+

# Appendix A: Carbon-Carbon Sheet Specification

Carbon-carbon panels carbonized and heat-treated to achieved performance
parameters listed in Table 1. Panels are to be densified by a CVD carbon
process and resin impregnated with RS3 cyanate ester. Scrub plates to
remove excess resin.

Panel size: 48.26 cm (19 in.) square or larger.

Number of panels: Preproduction lot a minimum of 2 panels. Production
lot of minimum of 24 panels.

Layup: Quasi-isotropic 8 layers: 0/45/-45/90/s

+-----------------------+-----------------------+-----------------------+
| ####### Item          | **Specification**     | **Range or Comment**  |
| {#item-1 .unnumbered} |                       |                       |
+-----------------------+-----------------------+-----------------------+
| Tensile modulus-0°    | 158.6 GPa (23 Msi)    | ###### Range +/-5% {# |
| dir.                  |                       | range--5 .unnumbered} |
+-----------------------+-----------------------+-----------------------+
| Tensile modulus-90°   | 151.7 GPa (22 Msi)    | Range +/-5%           |
| dir.                  |                       |                       |
+-----------------------+-----------------------+-----------------------+
| Tensile strength-0°   | 296.4 MPa (43 ksi)    | Range +/-5%           |
| dir.                  |                       |                       |
+-----------------------+-----------------------+-----------------------+
| Tensile strength-90°  | 296.4 MPa (43 Msi)    | Range +/-5%           |
| dir.                  |                       |                       |
+-----------------------+-----------------------+-----------------------+
| CTE-0° dir.           | -1.2 ppm/K            | Range +/-10%          |
+-----------------------+-----------------------+-----------------------+
| CTE-90° dir.          | -1.2 ppm/K            | Range +/-10%          |
+-----------------------+-----------------------+-----------------------+
| Conductivity K~ab~-0° | \>170 W/mK            | Target value: \>190   |
| dir.                  |                       | W/mK                  |
+-----------------------+-----------------------+-----------------------+
| Conductivity K~c~-90° | \>170 W/mK            | Target value: \>190   |
| dir.                  |                       | W/mK                  |
+-----------------------+-----------------------+-----------------------+
| Conductivity K        | \>20 W/mK             | Target value: \> 25   |
| transverse            |                       | W/mK                  |
+-----------------------+-----------------------+-----------------------+
| Density               | 1.75 g/cc             | Range +5/-2%          |
+-----------------------+-----------------------+-----------------------+
| Thickness             | 0.406 - 0.457 mm      |                       |
+-----------------------+-----------------------+-----------------------+

# Appendix B - Reticulated Vitreous Carbon Foam Specification

Reticulated vitreous carbon foam to be supplied in sheets (size to be
specified by typical is 25x25x1 cm). Foam to be densified by chemical
vapor deposition to density of 0.1 +/- 0.01 gm/cm^3^.

# Appendix C - Aluminum Tube Specification

Extruded aluminum-tube (3003 alloy). Exact dimensions are to be
determined. Tolerance on exterior dimensions is +/- 0.020 microns.

# Appendix D - Drawings of Aluminum-Tube Sector

Drawings of the aluminum-tube sector follow.