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| ![               | ATLAS Pixel Detector |              |           |
| ](media/image1.w |                      |              |           |
| mf){width="0.932 | Assembly and Testing |              |           |
| 6388888888889in" | of the Pixel         |              |           |
| h                | Detector System      |              |           |
| eight="0.975in"} |                      |              |           |
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| ATLAS Project    | ###### ABS it        | Created :    | Page: **1 |
| Document No:     | em number {#abs-item | 28/06/01     | of**      |
|                  | -number .unnumbered} |              | ***12***  |
+------------------+----------------------+--------------+-----------+
| ATL-IP-QA-0007   |                      | Modified **: | Rev. No   |
|                  |                      | 17/01/2002** | .:        |
|                  |                      |              | **2.1**   |
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+-----------------------+-----------------------+-----------------------+
| ATLAS Pixel Detector  |                       |                       |
|                       |                       |                       |
| Assembly and Testing  |                       |                       |
| of the Pixel Detector |                       |                       |
| System                |                       |                       |
|                       |                       |                       |
| Abstract              |                       |                       |
|                       |                       |                       |
| Version 15/11/01      |                       |                       |
|                       |                       |                       |
| This document         |                       |                       |
| describes the         |                       |                       |
| requirements for the  |                       |                       |
| assembly and testing  |                       |                       |
| of the pixel detector |                       |                       |
| on the surface in the |                       |                       |
| SR-building prior to  |                       |                       |
| its installation in   |                       |                       |
| the underground       |                       |                       |
| experimental area.    |                       |                       |
+-----------------------+-----------------------+-----------------------+
| Prepared by:          | Checked by:           | Approved by:          |
|                       |                       |                       |
| G.Lenzen              |                       |                       |
|                       |                       |                       |
| M.Olcese              |                       |                       |
+-----------------------+-----------------------+-----------------------+
| Distribution List     |                       |                       |
+-----------------------+-----------------------+-----------------------+

+---------+---------+---------+----------------------------------------+
| History |         |         |                                        |
| of      |         |         |                                        |
| Changes |         |         |                                        |
+---------+---------+---------+----------------------------------------+
| Rev.    | Date    | Pages   | Description of changes                 |
| No.     |         |         |                                        |
+---------+---------+---------+----------------------------------------+
| 1       | 2       |         | General update                         |
|         | 2/08/01 |         |                                        |
| 2.1     |         |         | Editing for the Integration FDR        |
|         | 2       |         |                                        |
|         | 0/01/03 |         |                                        |
+---------+---------+---------+----------------------------------------+

TABLE OF CONTENTS

1 INTRODUCTION [4](#introduction)

2 OUTSIDE CERN ASSEMBLY SITES [4](#outside-cern-assembly-sites)

2.1 Bi-Stave Integration \[Eric V.\] [4](#bi-stave-integration-eric-v.)

2.2 Half Shell Assembly \[Charlie, Bernd\]
[4](#half-shell-assembly-charlie-bernd)

2.3 Disk Assembly \[Gil\] [5](#disk-assembly-gil)

3 THE SR-BUILDING ON THE ATLAS SITE \[to be updated by Lenzen\]
[5](#the-sr-building-on-the-atlas-site-to-be-updated-by-lenzen)

3.1 OVERVIEW OF ASSEMBLY AND TESTING IN THE SR-BUILDING
[8](#overview-of-assembly-and-testing-in-the-sr-building)

3.2 Barrel assembly \[to be updated by Charlie, Bernd\]
[9](#barrel-assembly-to-be-updated-by-charlie-bernd)

3.3 Disk assembly \[to be updated by Gil at al.\]
[9](#disk-assembly-to-be-updated-by-gil-at-al.)

3.4 Final integration of the pixel detector parts into the ITT \[to be
updated by Danilo/Andrea R.\]
[9](#final-integration-of-the-pixel-detector-parts-into-the-itt-to-be-updated-by-daniloandrea-r.)

3.5 Service panels integration \[Neal/Eric A.\]
[9](#service-panels-integration-nealeric-a.)

4 SPECIFIC REQUIREMENTS FOR THE PIXEL AREA OF SR BUILDING \[to be
updated by Lenzen\]
[10](#specific-requirements-for-the-pixel-area-of-sr-building-to-be-updated-by-lenzen)

4.1 Fixed infrastructures [11](#fixed-infrastructures)

4.2 Specific mobile tools/equipment \[Danilo\]
[12](#specific-mobile-toolsequipment-danilo)

5 Tests [12](#tests)

5.1 Survey and Mechanical tests \[Danilo\]
[12](#survey-and-mechanical-tests-danilo)

5.2 Electrical & electronic Test \[Kevin\]
[12](#electrical-electronic-test-kevin)

5.3 System Test \[Kevin\] [12](#system-test-kevin)

6 TIME SCHEDULE AND MANPOWER \[to be update Danilo/Marco/Leo\]
[13](#time-schedule-and-manpower-to-be-update-danilomarcoleo)

7 APPENDIX A: breakdown of pixel assembly Tests
[14](#appendix-a-breakdown-of-pixel-assembly-tests)

#   {#section .unnumbered}

# 

# INTRODUCTION

This document describes how the pixel detector system will be assembled
and tested in various Collaboration Labs and in the SR-building situated
close to the CERN point 1 ATLAS pit.

It is assumed that the whole pixel detector including the B-layer and
the ATLAS beam-pipe will be assembled and tested on the surface and then
installed as a "package" into the ATLAS detector in the cavern.

# OUTSIDE CERN ASSEMBLY SITES

The ATLAS pixel detector consists of three barrel layers and three disks
each for the two disk sections as shown in Figure 1. The complexity of
the detector and numerous test procedures necessitate the setting-up of
different assembly sites where pixel sub-detector parts are assembled
and tested before being sent to CERN.

![](media/image2.jpeg){width="7.761023622047244in"
height="3.358267716535433in"}

Figure 1 The pixel detector.

The barrel Bi-staves will be mounted on half-shell supports in France
(Marseille), Germany (Wuppertal) and Italy (Genoa), while the pixel
disks will be mounted to the disk ring supports in the U.S. (Berkeley).

The assembly and testing of the pixel detector at CERN will take place
under the following working hypothesis:

The six barrel half shells (with a total of 112 staves) and six end-cap
disks (with a total of 48 sectors) will arrive at CERN from the assembly
sites fully equipped (including services) and tested.

The overall support frame made out of three pieces (one barrel and two
end-cap global support sections) fully assembled get to CERN.

All tooling and equipment necessary for the final pixel detector
assembly, test, and installation will be available at CERN.

The beam pipe will be available by the time of the final assembly.

The assembly of the sub-detector parts and all further tests before the
final installation in the cavern will be carried out in the SR-building
at the ATLAS pit 1.

## Bi-Stave Integration \[Eric V.\]

Explanation of the Bi-stave assembly procedure and tools

## Half Shell Assembly \[Charlie, Bernd\]

Explanation of the Bi-stave assembly procedure and tools (HAS,
SSBA&SSBC)

## Disk Assembly \[Gil\]

The disk system will be preassembled and partially tested at Lawrence
Berkeley National Laboratory(LBNL) before arrival at CERN. The disk
system consists of two identical disk frame sections with disk rings(see
Figure 1). All disks are identical.

Each disk is composed of eight identical sectors, each with six pixel
modules and associated local cables, a disk ring to hold the sectors and
four mounts to attach the disk-ring assembly to the disk frame section.

The status of these elements is as follows. Both disk frame sections
have been fabricated. All disk rings have been fabricated. Disk ring
mounts have been fabricated. Sector fabrication is in progress. These
parts are shown in Figure 2. The location of the rings in the frame is
fixed by drilling holes in the frame and precision bonding of mount
parts. This has been fully demonstrated on a prototype but remains to be
done for the production parts. It is planned to complete this step by
July 2003. The assembly of production sectors with pixel modules onto
disk rings is planned to begin in March 2004.

Sectors will be assembled and tested at LBNL. The locations of the pixel
modules on each sector will be surveyed to locate the modules relative
to the sector mounting holes. The sectors will be mounted by hand onto
the disk rings(the hole locations on each disk ring will have been
previously surveyed) using precision, custom fasteners(bolts).. We do
not expect to survey the location of pixels modules once the sectors are
attached to the disk ring(although this could be done if necessary).

Each disk ring will be mounted for assembly and testing in an aluminum
"ring box" that will support the ring, provide access to mount sectors
and support the local cables and the cooling tubes exiting from the
sectors. The ring will also be tested in this box, which will provide a
dry environment. Testing at LBNL will be done with liquid cooling. Note
that each sector will be housed and tested in the same way in a sector
test box before mounting on a disk support ring. This will included cold
testing at the sector level but cold testing at the ring level is not
planned, but could be implemented. At a minimum, two sectors at a time
will be tested electrically after mounting on the ring. The capability
exists to test a complete ring if necessary. The testing will occur as
the (bi)sectors are completed on a ring. The design of the ring assembly
and testing box has not started but will begin by September 2003.

![](media/image3.jpeg){width="2.749212598425197in"
height="2.709055118110236in"}![](media/image4.jpeg){width="3.249212598425197in"
height="2.693700787401575in"}![](media/image5.jpeg){width="1.1661417322834646in"
height="0.8744094488188976in"}

Figure 2 Photographs of a disk frame section, a disk support ring and a
preproduction disk sector.

Each ring will undergo a trial insertion into it's final location in a
frame but testing will not occur in the frame. (Obviously trial
insertions with just the mechanical structure will have already
occurred). Cables and pipes from the disks are held by clamps(strain
reliefs) that are attached to threaded holes in the disk frame. The
location and suitability of these clamps will be tested in the trial
insertion. The ring will be put back into its box and tested again after
the trial insertion and removal. The tooling for this will consist of a
simple rail system and cart to hold and adjust the disk frame section
and another cart to hold a short cantilever tool holding the disk ring
and the associated cables. The carts are moved together and the mounts
engaged into the frame and tightened by hand. The design for this
tooling has not started(except for those parts that are common to allow
drilling mount holes in the frame) but will begin by April 2003.

Each ring box will be mounted in a custom shipping box for shipment to
CERN after all testing is complete.

The two frame sections, the rings in their testing boxes and all tooling
that was used for trial assembly at LBNL will be shipped to CERN to the
SR building. The rings in their boxes will be unpacked and tested. Spare
sectors will also be shipped. If a sector is somehow damaged, it will be
replaced by hand at CERN and retested. The first testing with
evaporative C~3~F~8~ will occur at onlyCERN(although a vacuum leak test
will have occurred at LBNL). This testing will occur ring-by-ring, each
in it's own test box(augmented by local insulation) in a nitrogen
environment. Insertion of rings into the disk frame section will then
occur using the same tooling and procedures as done at LBNL. The need
for a final survey of the disk positions at this point is not yet
understood but will follow from trial insertion and survey using a touch
CMM of just the mechanical parts at LBNL during summer 2003.

# THE SR-BUILDING ON THE ATLAS SITE \[to be updated by Lenzen\]

The assembly and testing of the ATLAS Inner Detector (Pixel detector,
SCT, TRT) prior to its installation into the underground experimental
area are foreseen on the surface in building 2175, the so-called
SR-building, on the ATLAS pit 1 site. This building is already existing
and was used so far by the LEP machine, but it has to be modified to
match the needs of the ATLAS Inner Detector groups.

The SR-building is expected to be handed over of the Inner Detector
groups after mid 2002!!!!!. Only then the detector specific tasks like
the installation of cables and pipes for testing the sub-detectors will
be performed.

A lot of requirements for the assembly and testing of all parts of the
Inner Detector have to be taken into account. The building will be:

air-conditioned (temperature 22±2 °C and humidity 40±10 % controlled)

moderately clean ( 30000 level cleanliness for the entire assembly area)

equipped with additional local dust trapping

equipped with local movable screens

access controlled

No cold storage area for any detector element is foreseen.

The SR-building is subdivided into several zones (see figure 1),
especially important are:

a big assembly and test area of about 35.5m x 15.8m in common for the
Pixel, SCT, and TRT parts of the Inner detector

a specific area for barrel TRT and SCT integration and test*a s*

a service areas for power supply racks and cooling system

a control room

a storage area as repository for tools and specific movable equipment.

The big common assembly and test area will be subdivided by means of
local movable screens in order to satisfy the needs of all Inner
Detector communities. The option of installing a separate air-handling
unit (AHU) at a later stage for a possible class 10000 clean room will
be kept open.

![](media/image6.png){width="6.802083333333333in"
height="2.8541666666666665in"}

Figure 1: layout of SR building

The sharing of part of the big clean area between the SCT, TRT and pixel
detectors is posing no problem due to the foreseen later arrival of the
pixel parts.

However, a trial assembly of the major pixel detector support structures
is foreseen one year before the start of final assembly.

This trial assembly could be carried out in an area with no specific
requirements in terms of equipment/systems as no tests are foreseen,
except mechanical handling. Therefore it could be performed anywhere in
the assembly area.

On the contrary, the final assembly and integration has to be performed
in an area close to all the permanent installations and equipments
needed to carry out the functionality tests.

The area currently allocated to the assembly and testing of the pixel
detector has a size of 16m x 6m.

This area size is "just" the required minimum and its length is just
sufficient for the final integration of the pixel package and hence
cannot be reduced by any means.

It is assumed that some tools and equipment for the assembly and testing
will be stored in other areas when not in use.

If it turns out to be necessary, the local screens in the pixel, SCT and
the barrel TRT assembly area can be moved after mutual agreement in
order to reduce or enlarge the areas as needed by the individual ID
communities. Though being cost effective, this flexibility in
subdividing the area necessitates good communications and information in
time between the three ID sub-groups.

All power supplies and cooling racks/units will be located in the
dedicated racks and services area. This room will be connected to the
area foreseen for the pixel detector via cable and pipe channels under
the floor in order to perform the necessary tests of the system.

The evaporative cooling plant in the SR-building is designed to be a
common item for both SCT and pixel detector. The plant should be
equipped with local manifolds so that a fast connection to the to be
tested part of the Inner Detector (SCT and/or Pixel) is made possible.

It is under discussion to transfer a Milano group owned CMM from
building 15 on the CERN 1 site into the SR-building. As its present
floor only stands a load of about 500 kg/m^2^, a small part in the
corner of the pixel area in the order of 4 m^2^ has to be reinforced for
providing additional stability to the device during measurements.

The measuring volume of the CMM is about 1.0m x 0.8m x 0.6m and it
weights about 1500kg.

The CMM will be used in particular to survey the position of Bi-staves
into half-shells

The measurements performed by the CMM will then be merged with the
measurements performed at each assembly site for sub-assemblies. These
measurements would give the initial input to a final more precise
alignment of the detector in beam position, which will be performed with
the help of particle tracks during operation.

## OVERVIEW OF ASSEMBLY AND TESTING IN THE SR-BUILDING 

At the arrival at CERN of the six half shells of the barrel and the six
disks an initial acceptance will be done in order to determine if damage
occurred during shipment. Most of these structures have never been
tested with the final evaporative system, so this initial test is meant
also to check the performances of staves and sectors in real operating
conditions before proceeding with any other assembly step.

This test will mainly consist of:

a visual inspection

System test: a full functional test of the modules (up to 10% of the
total capacity at a time)

If a component on a stave or disk sector is found to be faulty a whole
stave or disk sector is then to be replaced. No repair of any individual
parts of a stave or sector foreseen in the SR-building. These repairs
are either done in the home institutes (assembly sites) or in a
specifically equipped building on the CERN site (for example building
186).

The full functional test with evaporative cooling will be repeated only
after final integration of the system inside Dummy Support Tube (DST).
Other intermediate basic functional tests of the modules will be carried
out during the assembly.

A moderate gas cooling system with Helium is sufficient for this
purpose, since it will allow to test module by module of one stave (13
modules/stave) or one disk sector (6 modules/sector) with a power of
less than 100 Watt, avoiding the operation of the more complicated and
powerful evaporative cooling system.

After having performed all initial acceptance tests of half shells and
disks the complete assembly of the pixel detector will take place in
five main steps:

Layer 1 and layer2 assembly: The Two half shell are clamped in one full
layer

assembly

Barrel assembly: layer 1 + layer 2 + barrel frame + end cones are
integrated by means of the ITT. This procedure is called Barrel
assembling

Disk section assembly: Rings are assembled in the Disk Section Frame

Package integration into the ITT: Beam pipe and B-layer are assembled
with the barrel. Disks and services panels are installed too.

The Package assembly is moved to the Dummy Support Tube.

This rather recent assembly scenario leads to the fact that the B-layer
is not independent any more from the other parts (barrel, disk
sections). In fact, in order to take out the B-layer from the rest of
the pixel detector, first both disk sections have to be removed to
access the B-layer. Because of restricted space inside the ATLAS
detector and remaining high radiation levels even after switching-off
the LHC, this and any other operation is more conveniently done on the
surface. Therefore the whole pixel detector is supposed to be taken
again into the SR-building (by means of the ITT) in case of serious
repair and maintenance.

The following sections explain in some detail the assembling and testing
of the barrel and the disk parts of the pixel detector before the global
assembly of the whole pixel detector is described.

The detailed breakdown of the assembly and testing steps with some basic
description of procedures and tools needed is reported in appendix A.

## Barrel assembly \[to be updated by Charlie, Bernd\]

-   
-   

## Disk assembly \[to be updated by Gil at al.\]

The two frame sections, the rings in their testing boxes and all tooling
that was used for trial assembly at LBNL will be shipped to CERN to the
SR building. The rings in their boxes will be unpacked and tested. Spare
sectors will also be shipped. If a sector is somehow damaged, it will be
replaced by hand at CERN and retested. The first testing with
evaporative C~3~F~8~ will occur at onlyCERN(although a vacuum leak test
will have occurred at LBNL). This testing will occur ring-by-ring, each
in it's own test box(augmented by local insulation) in a nitrogen
environment. Insertion of rings into the disk frame section will then
occur using the same tooling and procedures as done at LBNL. The need
for a final optical survey of the disk positions at this point is not
yet understood but will follow from trial insertion and survey using a
touch CMM of just the mechanical parts at LBNL during summer 2003.

## Final integration of the pixel detector parts into the ITT \[to be updated by Danilo/Andrea R.\]

## Service panels integration \[Neal/Eric A.\]

# SPECIFIC REQUIREMENTS FOR THE PIXEL AREA OF SR BUILDING \[to be updated by Lenzen\] 

A budget of 120 kCHF distributed over three years is foreseen for the
setting up of the assembly and testing area of the pixel detector in the
SR building. The sum should cover all the specific basic infrastructures
for the pixel detector not included in the general supplies of the
buildingI suppose so.

The reinforced floor for the CMM and uninterrupted power supplies (UPS)
are part of this budget.

Cables and cooling pipes for testing the pixel detector are counted
separately and are not part of above budget.

It is assumed that the SR-building has to be equipped with cooling,
cables, and read-out for 10% of the pixel system. Therefore a cooling
capacity of about 3 kW is needed. This equipment is supposed to remain
permanently in the SR-building for later maintenance and eventual
upgrading of the pixel system.

All the ROD and DCS will go into the rack area. Local links (inside the
test area) to computers for monitoring and control are needed.

All sub-parts of the pixel detector and tools will be transported to the
SR-building. Special care will be taken to minimize the risks of
breaking these parts during the transport from the assembly sites to
CERN.

The size of the assembly area reserved for the pixel detector allows in
principle to work simultaneously on the barrel and at least one end-cap
part in an independent way.

A first basic layout of the pixel assembly and testing area is shown in
figure 2.

Trial assembly tests will be carried out one year earlier than the final
assembly will take place.

These tests could be performed anywhere in the assembly area, since they
are purely mechanical and do not require any of the equipment of the
pixel area.

The area needed for the trial assembly is about 16m x 3m.

![](media/image7.wmf)

## Fixed infrastructures

The following fixed infrastructures should be installed in the pixel
area:

Inert gases:

Concerning the supply of different kinds of non flammable gases, only
Nitrogen and Helium should be used. Compressed air is disfavoured
because of its possible contamination by traces of oil. Either Nitrogen
and Helium are taken from dewars, or, more conveniently, batteries with
12 bottles each can be used. In both cases the primary pressure of the
gases is more than 200 bar and pressure reducers and flow limitations
have to be provided. The purity of the gases should be 99.9% . However a
dedicated line of compressed air, with oil traps will be needed for the
CMM.

Vacuum ports:

Two normal vacuum ports (pumping speed and vacuum level to be
determined) will be needed in the assembly area to operate some assembly
jigs.

Module power supplies connections:

For testing the pixel detector system before its final installation in
the cavern up to 10% of the total amount of modules will be tested at a
time. Therefore power supplies for about 160 modules have to be
available in the rack and control rooms. Six former DELPHI racks are
foreseen in the racks and tooling area of the SR-building. Two racks
will be equipped with the read-out electronics and electronics for test
systems. All power supplies for the pixel detector system will be
implemented in additional two racks. And there is foressen one rack each
for the Detector Control System (DCS) and the three UPS systems.

Cooling connections:

There are two C3F8 cooling manifolds foreseen with 6 input and output
connections each.

Electrical supplies

In case of unforeseen power cuts, uninterrupted power supplies are to be
available in order to guarantee the functioning of important devices, as
the online DCS system and computers. A capacity of about 2kW for the UPS
is adequate. There are three UPS with a capacity each of 1kW available
from the former DELPHI experiment.

[Network connections]{.underline} (to be determined)

The SR-building will be connected to the CERN computer center, and at
least three network connections will be available in the pixel assembly
area.

## Specific mobile tools/equipment \[Danilo\]

This section lists all the specific mobile tools/equipment to be
available in the area for relevant assembly/test steps.

The list will be filled in later on as soon as the detailed assembly and
testing procedures will be defined.

Initial acceptance test:

Cold box (size, power and cooling requirements)

# Tests

## Survey and Mechanical tests \[Danilo\]

## Electrical & electronic Test \[Kevin\]

## System Test \[Kevin\]

# TIME SCHEDULE AND MANPOWER \[to be update Danilo/Marco/Leo\]

The detailed time schedule for the production and installation of the
pixel detector is to be updated by the end of this year. Therefore only
a rudimentary schedule is given here.

The SR-building is to be handed over to the Inner Detector community by
about beginning 2003. At that time all requirements of cleanliness and
temperature/humidity control are implemented in this building. Therefore
the installation of the common evaporative cooling system, of racks and
crates for the power supplies, and read-out electronics can start.

The basic installation of all fixed equipment for the pixel detector
assembly and testing will take about a year till mid 2003.

Trial assemblies of some support structures are planned in late 2003 for
a few months.

The barrel and the both end-cap pixel detectors are expected to arrive
at CERN mid of 2004.

The final pixel system will have to be ready for the installation inside
ATLAS by beginning 2005.

During this period (6-8 months) the whole area assigned to pixel will
have to be available, because, due to very tight schedule, many
operations will have to be carried out in parallel.

A very rough plan of the pixel activities in SR building area up to
first commissioning is given in figure 3.

![](media/image8.wmf){width="6.6in" height="2.092361111111111in"}

Figure 3: plan for pixel activities in SR-building

Concerning the manpower needed for the assembly and testing the size of
the detector has to be taken into consideration. The delicate work on
fragile pixel detector elements demands skilled technical manpower. It
is envisaged to assemble and test the detector with several small teams
of two to three persons.

# APPENDIX A: breakdown of pixel assembly Tests

In this appendix a breakdown of the assembly steps of the pixel system
from the arrival of the parts at CERN to the final integration into the
ITT is provided.

For each assembly step the tests to be performed are described and
relevant tools/equipment for assembly, testing, handling and
installation are identified.

This appendix will be available in next version.

#  {#section-2 .unnumbered}