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\begin{titlepage}
\begin{LARGE}
\hspace*{12.0cm}
\parbox[t]{50mm}{
{\bf 26 April 1999}\hfill\\
{\bf DRAFT}\hfill \\
}
\end{LARGE}
\vspace{10mm}

\begin{center}
\fbox{\rule[-15mm]{0mm}{16mm}
\parbox{140mm}{
\begin{center}
{\Huge\bf Quality Assurance} \\
\hfill \\
\hfill \\
\hfill \\
{\LARGE\bf for ATLAS MDT Chamber Construction} \\
\end{center}
}}
\vspace{20mm}

{\LARGE\bf Task Owner QA/QC Procedures}\hfill \\
\vspace{40mm}


\noindent
{\Large Description of the Quality Assurance Procedures for the Construction
\vspace{2mm}

of the Monitored Drift Tube chambers for the ATLAS muon spectrometer.}

\end{center}




\end{titlepage}

\tableofcontents
\clearpage

%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%

\chapter{Introduction--The Quality Assurance Plan}
%
The performance goals of the ATLAS muon spectrometer require unprecedented 
mechanical precision in the construction of the large 
number of Monitored Drift Tube chambers (1194) built at many production sites (11)
over a period of more than 4 years. At the same time, the reliability the large number of
drift tubes (371000) and chambers must be very high.

Measurement of the wire locations in assembled chambers and verification of their
accuracy with the X-ray tomograph can only be performed
for a fraction of the chambers, approximately $15~\%$.

The strategy for the distributed, large-scale production of the 
precision chambers is to guarantee the mechanical precision of drift tubes and
assembled chambers by the design of the components and of the assembly method and tooling
supplemented by an extensive monitoring program and detailed quality assurance
plan for all production sites.

In addition, in a common quality control program of
the important parameters for the reliability and performance of individual drift
tubes and of assembled chambers are tested. The quality control tests are
designed such that they safely detect bad drift tubes and chambers while they
can be performed at all production sites and keep up with the production rate.
Only small failure rates are acceptable in the production process. The main
purpose of the tests is to provide quick feed back for adjustment of the
assembly tooling in the case of problems.

Faulty chamber components and drift tubes will be rejected. The failure rate
of assembled drift tubes must not exceed the few percent level.
Chambers failing the quality control tests have to be repaired
(identification of leaks, sputtering of noisy tubes);
faulty tubes in a chamber which cannot be recovered will be disconnected.
Chambers exceeding the mechanical accuracy requirements can be recovered
by measureing the wire locations with the X-ray tomograph. Only in exceptional
cases chambers will have tobe rejected.

\noindent
The quality assurance procedures for MDT chamber construction
can be broken down into the following steps:

\begin{enumerate}

\item Chamber Components and Materials,

\item Drift Tube Assembly,

\item Drift Tube Test,

\item Chamber Assembly,

\item Chamber Test,

\item Transport and Storage.

\end{enumerate}

The quality assurance procedures for each step are decribed in this document.
Quality control of the readout electronics and data aquisition to be mounted
on the chambers during storage time or installation in ATLAS is described
in separate documents.

Detailed archiving of the monitoring and test data is necessary in order
to evaluate and control the production process and to provide complete
documentation for the operation of the chambers. The data will be stored
in local and central detector data bases. The locally stored data allow the detection
and tracing of errors during chamber production. The central data base contains
information relevant for the operation of the chambers in ATLAS.

In addition, local and central production data bases keep the information to control
the delivery and stock of components and the completion, transport and storage of
drift tubes and chambers.

An internal review of each production site will take place before
module~0 construction at the site in order to ensure that all procedures
and tools follow the specifications.

Before the start of series production, each production site will be qualified
based on the data from module~0 construction and test.

The production sites are requested to report any problems occuring during tube
and chamber assembly. Production should not continue before the problems are not
identified and solved in consultation with the other production sites.

%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%

\chapter{Documentation}
%
Information relevant for quality assurance and control of the MDT chamber construction 
is contained in the following documents:

\begin{enumerate}

\item {\bf Chamber and Assembly Tooling Specifications:}
 
Technical Design Report for the ATLAS Muon Spectrometer and updates, including documentation for
ATLAS Production Readiness Reviews.

\item {\bf Procurement Documents for Chamber Materials:}

Tendering documents and contracts with suppliers for the chamber components listed below.

\item {\bf Drift Tube Assembly Manual:}

Describes all steps of the drift tube assembly including QA/QC procedures.
The assembly plan will be partially implemented in a Tube Assembly Control Program.

\item {\bf Drift Tube Test Manual:}

Describes detailed steps of the tube test procedures.

\item {\bf Chamber Assembly Manual:}

Describes all steps of chamber assembly including QA/QC procedures;
The assembly plan will be partially implemented in a Chamber Assembly Control Program.
Associated with the manual are instructions for the use of the monitoring devices and
the handling of the glue.

\item {\bf Chamber Test Manual:}

Describes all steps of the chamber test procedures.

\item {\bf The QA/QC Document:}

Summarizes the quality assurance strategy and procedures, including
quality control tests and instructions for handling,
transport and storage of chamber materials, drift tubes and assembled chambers.

\end{enumerate}

The above manuals serve as references and guidelines for the preparation of 
local manuals and work plans and the implementation of coherent
quality assurance procedures at all production sites.


\section*{Documents Relevant for MDT Quality Assurance Procedures:}
%
\subsection*{General}
%
\begin{enumerate}

\item
ATLAS Collaboration, A.~Airapetian et al., 
{\sl ATLAS Muon Spectrometer Technical Design Report},
CERN/LHCC/97-22, May 1997.

\item 
F.~Linde et al., {\sl MDT Quality Assurance for Module~0 MDT Chambers},
ATLAS Internal Note, ATL-MUON-98-238, May 1998 (replaced by this document).
\end{enumerate}

\subsection*{Specifications and Procurement of Components}
%
\begin{enumerate}

\item
Technical Specification, {\sl Supply of Gold-Plated Tungsten-Rhenium Fine Wire
for the ATLAS Muon Spectrometer (Module-Zero Chambers)},
for Price Enquiry: DO-1045107, September 1998
(CERN).

\item 
Technical Description, {\sl Supply of Endplugs
for the ATLAS Muon Spectrometer},
for Market Survey: MS-2575/EP/ATL, October 1998
(CERN).

\item 
Technical Specification, {\sl Supply of Aluminum Alloy Extruded Profiles
for the ATLAS Muon Spectrometer (Module-Zero Chambers)},
for Price Enquiry: DO-98010, October 1998
(NIKHEF).

\item 
Technical Specification, {\sl Supply of Thin-Walled Precision Aluminum
Alloy Tubes
for the ATLAS Muon Spectrometer (Module-Zero Chambers)},
for Invitation to Tender: IT-2549/EP/ATL, November 1998
(CERN).

\end{enumerate}

\subsection*{Drift Tube Assembly}
%
\begin{enumerate}

\item
R.~Dumps et al., {\sl A Prototype Wiring Automate for the Twister/Tango
Based Endplug of the ATLAS Muon Drift Tubes},
ATLAS Internal Note, ATL-MUON-98-267, January 1999                                                                                            
(CERN).

\item
University of Michigan ATLAS group, {\sl Michigan Wiring Table, 
MDT Tube Assembly Electronics Control and Computer Program},

http://ganesh.physics.lsa.umich.edu/\~ atlas 

(Michigan).

\end{enumerate}

\subsection*{Chamber Assembly}
%
\begin{enumerate}

\item
G.~Kaptsis et al., {\sl Mechanical Design of the BIS Module Zero MDT Chamber},
ATLAS Internal Note, ATL-MUON-98-242, June 1998
(Thessaloniki).

\item
G.~Ciapetti et al., {\sl A QA/QC System to Monitor the Planarity of the Tube Layers
in MDT Chambers Construction},
ATLAS Internal Note, ATL-MUON-98-255, September 1998
(Rome~I).

\item
V.~Bartheld et al., {\sl Construction of the Full-Scale Prototype
of a BOS MDT Chamber},
ATLAS Internal Note, ATL-MUON-98-256, October 1998,

http://wwwatlas.mppmu.mpg.de/mdt.html

(MPI Munich).

\item
D.~Kalkbrenner, H.~Kroha and A.~Manz, {\sl Glue Dispenser for MDT Assembly
and Glueing Instructions}, January 1999,

ftp://wwwatlas.mppmu.mpg.de/outgoing/qaqc/glueing/glue\_ manual.ps

(MPI Munich).

\item
H.~Kroha, {\sl BOS Chamber Assembly Quality Assurance Plan},
February 1999,

ftp://wwwatlas.mppmu.mpg.de/outgoing/qaqc/bos\_ assembly\_ plan.ps (.pdf)

(MPI Munich).

\item
H.~Kroha, {\sl BOS Chamber Assembly and Test Plan},
February 1999,

ftp://wwwatlas.mppmu.mpg.de/outgoing/qaqc/bos\_ assembly\_ test.ps (.pdf)

(MPI Munich).

\item
H.~Kroha, {\sl BOS Chamber Assembly and QA/QC Data Base},
February 1999,

ftp://wwwatlas.mppmu.mpg.de/outgoing/qaqc/bos\_ qaqc\_ db.ps (.pdf)

(MPI Munich).

\item
Task Owners Chamber Assembly, {\sl Chamber Assembly Manual},
April 1999,

http://www.lnf.infn.it/\~ curatolo/BMLmanual.draft/

\item 
H.~Kroha and A.~Ostapchuk, {\sl Instructions for Optical Monitoring
of MDT Chamber Assembly}, April 1999,

ftp://wwwatlas.mppmu.mpg.de/outgoing/qaqc/monitoring/monitoring.ps (.pdf)

(MPI Munich).

\end{enumerate}

\subsection*{Drift Tube Test}
%
\begin{enumerate}

\item 
V.T.~Braic et al., {\sl Leak Detection System for Mass-Production
of Drift Tube Detectors}, 
ATLAS Internal Note, ATL-MUON-98-225, March 1998,

http://nuweb.jinr.ru/\~ dcbp/atlas/QAQC/gasleak/foto.htm

(Dubna).

\item
M.~Cambiaghi et al., {\sl An Electromagnetic Micrometer (EMMI) to Measure Wire Location
Inside an ATLAS MDT Drift Tube},  
ATLAS Internal Note, ATL-MUON-98-259, November 1998
(Pavia, Rome).

\item
A.~Balla et al., {\sl MDT Wire Tension Measurement Using an Electrostatic Method},
ATLAS Internal Note, ATL-MUON-98-264, November 1998
(Frascati).

\item
Pavia and Roma~I Atlas Groups, {\sl The Pavia--Roma~I MDT QA Facility},

ftp://cobra1.pv.infn.it/pub/MDT/mdt\_ qa.ps.gz

(Pavia, Rome~I).

\item
A.~Albanese et al., {\sl Quality Assurance and Quality Control for
ATLAS Drift Tubes at the Cosenza Production Site},
description of setup and quality control test plan,

ftp://fermi.cs.infn.it/atlas\_ qaqc

(Cosenza).

\item
University of Michigan ATLAS group, {\sl Michigan Leak Detector},

http://ganesh.physics.lsa.umich.edu/\~ atlas

(Michigan).
\end{enumerate}

\subsection*{Chamber Test}
%
\begin{enumerate}

\item
D.~Drakoulakos et al., {\sl The High-Precision X-ray Tomograph
for Quality Control of the ATLAS MDT Muon Spectrometer},
CERN-OPEN-97-023, July 1997
(CERN).

\item
CERN X-Ray Tomograph, http://wwwcn.cern.ch/\~ xtomo.

\item
C.~Bacci et al., {\sl Design of a Cosmics Test Site for the Quality Assurance and
Quality Control (QAQC) of Full MDT Chambers},
ATLAS Internal Note, ATL-MUON-98-241, June 1998
(Rome~III).

\item
N.~Hessey, A.~Staude and T.~Trefzger, {\sl Cosmic Ray Test Stand at the LMU Munich},
ATLAS Internal Note, ATL-MUON-98-266, December 1998
(LMU Munich).

\item
H.~Kroha, {\sl BOS Chamber Assembly and Test Plan},
February 1999,

ftp://wwwatlas.mppmu.mpg.de/outgoing/qaqc/bos\_ assembly\_ test.ps (.pdf)

(MPI Munich).

\end{enumerate}

\clearpage
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%

\chapter{Monitoring of Chamber Production}


\section{Archiving of Quality Control Data}

\section{Central Production Data Base}

\section{Local QA/QC Data Base}



\chapter{Chamber Components}
%
The main chamber components and materials to be controlled are:

\begin{itemize}  

\item Precision aluminum tubes.

\item Gold-plated W-Rh wire.

\item Precision endplugs and endplug components.

\item Spacer components.

\item Components of the optical alignment system.

\item On-chamber gas distribution system.

\item Faraday cages and patch panels.

\item Glue (several types).

\item Hedgehog boards.

\item Mezzanine cards with readout electronics.

\item Temperature and magnetic field sensors.

\item Protective covers.
\end{itemize}

Quality and tolerances of the chamber components delivered to the
chamber production sites are controlled in four steps:

\begin{enumerate}

\item Quality assurance by the supplier

\item Central monitoring of material production including sample tests at 
an responsible institute.

\item Acceptance tests and visual inspection at the chamber production sites.

\item Specification for packing, transport, storage and handling
of the components.

\end{enumerate}


\section{Aluminum Tubes}
%
The thin-wall aluminum tubes for the drift tubes of the MDT chambers follow
tight mechanical tolerances with respect to the outer and inner diameter
and the straightness in order to be suitable for the precision assembly of the chambers.

The tubes are cleaned on the inside and outside
by the manufacturer according to a cleaning procedure defined in detail
which has been approved by the collaboration after
ageing tests. The cleaning procedure must not be changed without the agreement
of the collaboration and after new ageing test have been performed with the
new cleaning procedure.

The mechanical tolerances and the cleanliness of the tubes must be
conserved during all further transport, storage and handling of the bare
tubes and of the assembled drift tubes (see: Drift Tube Assembly and Storage).

The precision aluminum tubes are procured  centrally via CERN.

\subsection{Quality Control by Supplier}
%
The following quality control tests of the bare tubes are required from the 
supplier with certification:

\begin{itemize}  

\item Chemical and mechanical analysis and ultrasonic test of the tube raw materials.

\item Geometrical tolerances of extruded tubes.

\item Geometrical tolerances of drawn and straightened tubes.

\item Geometrical tolerances, including straightness, of at least $10\%$ of finished
tubes of each batch.

\item Visual inspection of inside and outside of at least $10\%$ of finished
tubes of each batch, including proper deburring of tube ends.

\end{itemize}

Each finished tube is identified by a bar code (industrial format 39B) which
contains the production run number, a sequential tube identifcation number, tube length
and a date and appears also in alphanumeric form.

Quality control documents and data with reference to the tube bar codes are
provided to the collaboration
and are kept in the {\bf Production Data Base} for monitoring of the production.

Detection of small holes on the tube walls by the supplier, e.g.\ with the eddy current
method, is too expensive. Therefore, the walls of all drift tubes
have to be tested for gas tightness at the chamber production sites.

\subsection{Production Monitoring}
%
Production monitoring is done centrally at CERN including
the following sample tests per batch of tubes delivered to the chamber production sites:

\begin{itemize}  

\item Visual inspection, inside and outside (obvious defects or holes, cleaning,
deburring, straightness).

\item Geometrical tolerances with 3D metrology.

\item Chemical and mechanical analysis of the finished tube material.

\item Metallurgical analysis of the finished tubes.

\item Chemical analysis of inner tube surface (monitoring of cleaning procedure).

\item Quality control of cleaning procedure over time with the ageing test stand.

\end{itemize}

During tube assembly at the production sites, each tube is visually inspected at the inside and outside
for obvious defects, proper deburring and cleanliness.

\subsection{Quality Control at Production Sites}
%
Quality control tests of the bare tubes at the chamber production sites are summarized in Table~1.


\section{Wire}
%
The gold-plated tungsten-rhenium sense wire for the drift tubes is procured centrally via CERN.

\subsection{Quality Control by Supplier}
%
The following quality control tests of the wire are required from the supplier with certification:

\begin{itemize}  

\item Measurement of tensile strength at beginning and end of each spool.

\item Test of precentage of gold plating at beginning and end of each spool.

\item Visual and microscopic inspection of gold plating quality for at least first meters
of each spool.

\end{itemize}

Each wire spool is certified and labelled with date, wire length and production run number.

\subsection{Production Monitoring}
%
Production monitoring is done centrally at CERN including
the following sample tests per production run:

\begin{itemize}  

\item Measurement of diameter.

\item Microscopic inspection of gold plating quality.

\item Inspection of cleanliness.

\item Measurement of tensile strength.

\item Measurement of electrical conductivity.

\end{itemize}                                                                                                                                 

\subsection{Quality Control at Production Sites}
%
Quality control at the chamber production sites is summarized in Table~1.


\section{Endplugs}
%
The endplugs for the drift tubes consist of the following components:

\begin{itemize}  

\item Injection moulded insulator made of Noryl GFN3 with $30\%$ glass fiber,
machined to be concentric and coaxial with the aluminum ring reference surface.

\item Precisely machined metal inserts in the plastic body:

\begin{itemize}  

\item Aluminum ground ring with precise reference surface for drift tube
tube positioning on assembly combs and precise front face for accurate
endplug insertion.

\item Central brass insert holding the wire locator in a precisely concentric
and coaxial hole with respect to the reference surface.

\end{itemize}                                                                                                                                 

\item Precise wire locator, machined separately and held in the concentric hole
of the brass insert with an injection moulded Noryl clip.

\item Copper wire crimp tube inserted in central brass piece.

\item Brass sealing cap with signal pin to be screwed onto the brass insert.

\item Injection moulded Noryl gas connector sealed with two O-rings between
the front face of the plastic body and the signal cap.

\item Brass ground pin in contact with the aluminum ring in a screw hole
and with nut with washer.

\item O-ring for gas seal of the plastic endplug body in the aluminum tube.

\end{itemize}                                                                                                                                 

The endplugs and their components are not individually labelled for cost reasons.
Endplugs of different production batches are kept in separate boxes at each
production site and are not mixed during tube assembly to help the tracing
of problems.

The endplug components are procured centrally via CERN.
At least parts of the endplugs have to be assembled 
at the chamber production sites.

\subsection{Quality Control by Supplier}
%
The following quality control tests of the endplugs and their components
are required from the suppliers with certification for a fraction of at
least $2\%$ of the endplugs:

\begin{itemize}  

\item Visual inspection of the injection 
moulded piece: smooth surfaces without air bubbles or cracks, especially in the
O-ring grooves.

\item Inspection of the bulk of the injection moulded piece by cutting
longitudinally through the center: no enclosed air bubbles, no cracks.

\item Metal inserts must not detach under specified force.

\item Visual inspection of machined endplug components:

Proper cleaning and deburring, smooth surfaces, no sharp edges, no metal chips,
no scratches, no air bubbles or cracks in plastic piece.

\item Test of fitting of components.

\item Verification of all mechanical tolerances of endplug and wire locator
with 3D metrology.

\end{itemize}

\subsection{Production Monitoring}
%
The production is monitored by responsible institutes which centrally
perform the following sample tests per production batch:

\begin{itemize}  

\item Visual inspection of all parts:
Proper cleaning and deburring; smooth surfaces, no sharp edges, no metal chips,
no scratches, no air bubbles or cracks in the plastic parts.

\item Test of fitting of all components.

\item Verification of all mechanical tolerances 
of endplug and wire locator with 3D metrology.

\item Inspection of the bulk of the injection moulded piece by cutting
the endplug longituinally through the center: no enclosed air bubbles, no cracks.

\item High voltage test of a fraction of endplugs per production batch  
assembled in drift tubes filled with dry nitrogen: leakage currents below
2~nA up to a voltage of 5~kV.

\item Measurement of the shape and diameter of the wire locating hole
and of the concentricity with respect to the endplug reference surface
with a CCD camera.

\end{itemize}

\subsection{Quality Control at the Production Sites}
%
Quality control tests at the chamber production sites are summarized in Table~1.

During assembly of the endplugs at the production sites and during
preparation for tube assembly, all endplug components, including 
wire locator and crimp tube, are visually inspected for obvious defects
(no sharp edges, proper deburring, no metal chips, 
no scratches, no air bubbles or cracks in the plastic parts).

All O-rings are inspected for obvious defects during assembly on the endplug.
The O-rings must not be exposed to light during
storage or assembled on the endplugs to prevent ageing.

The endplug components are cleaned in an ultrasonic cleaning bath using
only pure ethanol. Other cleaning fluids are not allowed.


\section{Spacer Components}
%
The extruded aluminum spacer profiles are procured centrally via a responsible
institute which monitors the production. Machining of the profiles to reach the
final mechanical tolerances is the responsibility of each production site.

The mechanical tolerances of the extruded and cut profiles are verified
by the supplier and the responsible institute for each batch to be delivered.

The mechanical tolerances of the machined spacer components are verified
for each chamber at the chamber production sites. The glue gaps between
cross plates and tubes layers are verified during spacer assembly (see the
{\bf Chamber Assembly Manual}). The functioning of the sag compensation system is tested
after assembly on the spacer.

\section{Optical Alignment System Components}
%
The components of the ATLAS optical alignment monitoring systems installed on the
chambers during assembly are:

\begin{itemize}  

\item Components of RASNIK monitors (LED with mask, custom-fabricated lens
and CCD with infrared filter with housings)
for the in-plane alignment system.

\item Mounting platforms for components of the projective alignment monitors.

\item Mounting platforms for the axial/praxial alignment monitors.

\end{itemize}

The components are procured centrally
by responsible institutes which monitor the production and perform
sample tests.

The focal length of the RASNIK lens is specific for each monitor.
It is specified to be with $\pm 3$~mm within the nominal value (1/4 of the
distance between mask and CCD). This tolerance corresponds to a
maximum forseen longitudinal range of adjustment of $\pm 12$~mm of the
light source with mask with respect to the lens. This can be verified
on a special RASNIK test stand at the chamber production sites prior to
the spacer assembly.

As part of the chamber assembly procedure,
each in-plane alignment monitor will be adjusted and fully tested on the
spacer (sharp and analysable image of the center of the mask)
before permanent fixation.

Correct relative orientation of the RASNIK mask and CCD is important
and ensured with labelling by the supplier.

\section{On-Chamber Gas Distribution System}
%
The components of the on-chamber gas system are centrally procured
by a responsible institute which monitors the
production and the quality control by the suppliers.

The gas manifolds are preassembled at the chamber production sites and tested
for gas tightness and flow rate per tube (see Table~3). After mounting on the
chamber, the gas system is leak tested together with the whole chamber (see Tables 4 and 5).

Assembly and test of the on-chamber gas system is described
in the {\bf On-Chamber Gas System Manual} by the responsible institute.

\section{Faraday Cages and Patch Panels}
%
The fabrication and quality control of the Faraday cages and patch panels 
for readout electronics and optical, temperature and B-field monitors are
the responsibility of each institute.

\section{Glue}
%
All glue types used for chamber assembly are epoxy resin based two-component glues.
They have been selected because they provide
sufficient strength in contact with aluminum and handling and curing
time are suitable for chamber series production.
In dedicated tests and during chamber prototype construction,
the shrinkage of the selected glues was found to be small enough to prevent
significant chamber deformations. Epoxy resin based glues are
known to be radiation tolerant far beyond the radiation levels
in the ATLAS muon spectrometer.

Only glue from one supplier, Ciba Geigy, will be used at all production sites.
The glue types are all widely used standard products of the supplier
with well known properties and reliability.
The quality of the glue will therefore be guaranteed by the supplier.
Glue storage and handling will follow strictly the
recommendations by the glue supplier.
Storage time and conditions of the glue will be monitored at the
chamber production sites. 

Details of the glue types and the glueing procedures are described in the
chapter {\bf Chamber Assembly}.

\section{Hedgehog Boards}
%
The hedgehog boards are delivered to the chamber production sites fully tested
and certified. 

All boards will be visually inspected for obvious defects after delivery.
Correct positioning of the electrical contact holes is verified on a template
in order to avoid forces on the endplugs.

Before installation, the boards are cleaned in an ultrasonic cleaning bath.
After cleaning, the boards are handled only by using gloves.

Installation of the boards and high voltage test on the chamber takes place
in the chamber test stands at the production sites. 
The boards stay on the chamber.

\section{Mezzanine Cards}
%
The mezzanine cards with the readout electronics are delivered to the 
chamber production sites fully tested
and certified. The boards are visually inspected for obvious defects upon
delivery. Mounting of the cards on the chamber and
high voltage and functionality test will take place either in the local
chamber test stand or in the central storage area at CERN as soon as the
cards have been delivered.

\section{Temperature and B-Field Sensors}
%
The temperature and B-field sensors, including cables, are procured and 
fabricated centrally by responsible institutes and are sample tested by them.
The function of each sensor is tested at the chamber production site
before the installation on the chamber.

\section{Protective Covers}
%
The material for the protective covers for installation in the detector will 
be procured centrally. Cutting to size and installation on the chambers
is done at the chamber production sites.


%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%

\chapter{Drift Tube Fabrication}
%
\section{Drift Tube Assembly}
%
Operation of the large number of drift tubes in the ATLAS muon spectrometer
requires very high reliability with respect to wire tension, gas thightness and high voltage
stability. At the same time, the sense wires have to be
centered in the precision aluminum tubes with high accurcay: with $\pm 10~\mu$m rms relative
to the endplug reference surfaces in the $y$ and $z$ coordinates of the 
azimutally oriented tubes and with a tolerance of $\pm 100~\mu$m with respect
to the inner tube wall envelope. The wire tension has to stay inside tight
tolerances in order to predict the wire sag with high accuracy.

During series production, typically 50--100 drift tubes per day have to be assembled
and tested at each production site.
Because of the large number of tubes, rejection of only few
percent of the assembled drift tubes can be afforded after the quality control tests.

The drift tube assembly procedures are designed to guarantee the high precision
and reliability of the drift tubes:

\begin{itemize}  

\item The drift tubes are assembled in a temperature controlled clean room
of class 50000. The room is cleaned in regular time intervals.

\item The room temperature is controlled to be $20\pm 1^\circ$~C.
This allows to set the tube length and the wire tension of the assembled tubes 
with sufficient accuracy.

\item Automatic or semi-automatic wiring stations are used.

Manual handling of the wire is minimized.

\item Coaxiality of the endplugs with respect to the tube, the relative azimutal
orientation of the two endplugs of a drift tube and the drift tube length 
(defined as the distance between the aluminum front faces of the endplugs)
are determined by the assembly tooling.

\item Critical parameters of the drift tube assembly process are controlled
by computer:

tube temperature, jigging temperature, wire tension and pre-tension, pre-tensioning time,
parameters of the tube crimping and wire crimping mechanisms.

\item The wire is pre-tensioned to $70\%$ of the rupture limit of 620~g for
a defined time interval to minimize wire creep.

\end{itemize}

The {\bf Drift Tube Assembly Manual} contains
detailed instructions for handling and assembly of the drift tubes.
The main drift tube assembly steps are implemented in
a {\bf Drift Tube Assembly Control Program}.

In particular, the following procedures are applied to maintain the quality of the drift tubes:

\begin{itemize}  
\item The tubes are stored in the temperature controlled wiring room at least 12 hours
before assembly to adapt to the temperature.

\item During work in the tube wiring room, hair and shoe protection,
coats and gloves certified for clean rooms are used. Before entering the
clean room, clothes are changed in a separate chamber.

\item Before assembly, the endplugs are cleaned in an ultrasonic cleaning bath.
Only pure ethanol is allowed for cleaning of Noryl plugs.

\item The bare tubes, the endplugs, the wire and the assembled tubes are visually
inspected before, during and after the wiring procedure (see Tables~1--3).
They are only handled with gloves certified for clean rooms.

\item The sense wire is inserted into the tubes directly from the spool without
additional cleaning and risk of contamination.

\item The tubes are oriented such during tube wiring that the
bar codes will be accessible when the tubes are inserted into the chamber assembly combs.

\end{itemize}

\section{Drift Tube Ground Contact}
%
A reliable ground contact between aluminum tube and the aluminum ground ring of the
endplug which is long-term stable is ensured by laser spot welding at the tube ends 
with three spots per endplug.
Detailed instructions for the laser welding process are given in the 
{\bf Laser Welding Manual for Drift Tube Ground Contact}.

The quality of the laser welds is verified by the following procedures:

\begin{itemize}  

\item Visual inspection for each tube after laser welding: welds at correct place,
no deformations on the endplug reference surface, visible quality in agreement with reference
welds.

In case of problems, the laser and setup are adjusted and the welding on the effected tubes
is redone.

\item Inspection of randomly selected welded drift tubes under a microscope:
no obvious cracks in the welding spots.

In case of problems, the laser and setup are adjusted and the welding on the effected tubes
is redone.

\item At the start of production, a sample of welds from each production site is
evaluated metallurgically by cutting and inspection under the microscope or by
X-ray measurement.

\end{itemize}

%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%


\section{Tube Transport and Storage}
%
The aluminum tubes are cleaned on the inside and outside by the manufacturer.
Afterwards, the tubes are kept under clean conditions and
should not be cleaned anymore at the chamber production sites, especially not
on the inside.

The bare aluminum tubes and the assembled drift tubes are transported and stored
under the following conditions:

\begin{itemize}  

\item The tubes are always transported in stable wooden boxes like the ones
used for delivery of bare tubes from the manufacturer.

\item For drift tube transports, temperatures must not be outside the range $10-30^\circ$~C.

\item The individual tubes are kept separated from each other and held such that
that they cannot move inside the transport box.

\item The tube ends are closed and protected with soft pastic caps.

\item Inside the transport box and in storage, the tubes are enclosed air-tight
in a plastic bag containing dehumidifier bags.

\item After assembly and test, the drift tubes are always kept gas sealed until the
gas distribution system is installed on the chamber. 

During longer storage periods, the tubes should be filled with inert gas to prevent corrosion.

\end{itemize}


\chapter{Drift Tube Test}
%
Successful operation of the large number of drift tubes in the ATLAS experiment
requires, in addition to the high mechanical accuracy in the wire location,
very high reliability of the tubes with respect to high voltage and
noise stability, gas tightness and protection against ageing effects.

Quality control tests of the drift tubes therefore are a major part of the
chamber construction. They must ensure the reliability of the drift tubes
over a long lifetime. At the same time the tests are designed such that
they can be performed routinely in reproducible manner and fast enough to keep
up with the speed of the tube production at a rate of 50-100 tubes per day
at each production site. The tubes test stands which can be operated
automatically under computer control are under development (see Figure~2).

The following quality control tests are performed for each assembled drift tube
at the tube production sites:

\begin{enumerate}

\item Visual inspection and mechanical tolerances.

\item Wire tension (oscillation frequency) measurement.

\item Wire location measurement.

\item Gas pressure and leak test of the whole drift tube.

\item HV stability test:

\begin{enumerate}

\item Leakage current measurement.

\item Cosmic rate measurement (optional).

\end{enumerate}

\end{enumerate}


The ground contact resistance between tube and the aluminum ground ring of the
endplug is measured for a random sample of drift tubes after production and
monitored over time for selected drift tubes before assembly and in an assembled chamber.

If drift tube and chamber production sites do not coincide, instructions for packing and
transport of the assembled drift tubes have to be observed.

The following tests are recommended to be performed
at the accepting site for a random sample of the delivered drift tubes:

\begin{enumerate}

\item Visual inspection (defects on endplugs or tubes).

\item Leak test of endplugs.

\item Ground contact resistance (as above).

\end{enumerate}

The wire tension (oscillation frequency) is measured 
at the chamber production sites for each drift tube before assembly 
in the chamber.


\begin{sidewaysfigure}
%\begin{table}[p]
\renewcommand{\arraystretch}{0.95}

\begin{center}
\noindent
{\bf Table~1:} Quality control tests of drift tube materials at the chamber production sites 
\vspace{2mm}

\begin{tabular}{lllcl}

\hline\hline   
& & & &\\
{\bf Test} & {\bf Acceptance criteria} & {\bf Reaction if failed} & {\bf Data base} & {\bf Comment} \\ [1mm]
\hline

& & & &\\
\multicolumn{5}{l}{\bf Aluminum tube} \\ [1mm]

Visual inspection      & no obvious defects or holes, proper cleaning, & reject tube,    & central & 1: sample test/box \\
of inside and outside  & deburring, straightness, bar code, packing & notify supplier &         & 2: every tube before wiring \\
& & & &\\

Outer diameter envelope,   & $29970\pm 15~\mu$m & reject box & central & sample test/box \\
from 8 points on circumference   &               &  & &\\
& & & &\\

Wall thickness,   & $400\pm 30~\mu$m & reject box & central & sample test/box \\
at 8 points on circumference   &               &  & &\\
& & & &\\

Length $L$     & $L\pm 0.5$~mm ($L\le 4$~m) & reject box & central & sample test/box \\
               & $L\pm 0.7$~mm ($L >  4$~m) & & &\\
& & & &\\

Straightness   & insertion in jig  & reject tube, & central & sample test/box \\
               & without difficulties & notify supplier & & \\
\hline

& & & &\\
\multicolumn{5}{l}{\bf Wire} \\ [1mm]

Visual inspection & no defects of gold-plating,      & reject spool & central & 1: first meters and every 400~m \\
                  & proper cleaning, no kinks        &              &         & \hphantom{1:} per spool under microscope, \\
                  &                                  &              &         & 2: inspection during wiring \\
& & & &\\
\hline

& & & &\\
\multicolumn{5}{l}{\bf Endplug} \\ [1mm]

Visual inspection & proper cleaning and no obvious defects  & reject endplug, & central & 1: sample test/batch \\
                  & of plastic, O-rings, wire locator,      & notify supplier &         & 2: each endplug before wiring \\
                  & Al reference surface, crimp tube        & & &\\
& & & &\\

Outer diameter envelope,         & $30020\pm 10~\mu$m & reject batch & central & sample test/batch \\
from 8 points on circumference   &                    &              &         &            \\
({\bf optional}) & & & &\\                                                                                                                 
& & & &\\

Wire locator outer diamter       & within tolerance   & reject batch & central & sample test/batch \\
& & & &\\
\hline\hline

\end{tabular}
\end{center}

%\end{tabular}
\end{sidewaysfigure}
\clearpage


\begin{sidewaysfigure}
\renewcommand{\arraystretch}{0.95}

\begin{center}
\noindent
{\bf Table~2:} Quality control tests of drift tubes at the chamber production sites
\vspace{2mm}

\begin{tabular}{lllcl}

\hline\hline
& & & &\\
{\bf Test} & {\bf Acceptance criteria} & {\bf Reaction if failed} & {\bf Data base} & {\bf Comment} \\ [1mm]
\hline

& & & &\\
\multicolumn{5}{l}{\bf Drift tube} \\ [1mm]

Visual inspection     & no obvious damage of tube or endplug,     & reject tube,            & local & each tube after wiring,\\
                      & no visible defects of tube and            & adjust wiring station   &       & before chamber assembly \\
                      & wire crimp, tube correctly sealed & & &\\
& & & &\\

Aluminum tube outer & less than 30.020~mm  & adjust wiring setup & local & sample test/day  \\
diameter envelope  & & & & after wiring  \\
in endplug region & & & &\\
& & & &\\

Length $L$     & $L\pm 0.5$~mm         & reject drift tube,    & local & 1: sample test/day \\
               & at $20\pm 1^\circ$~C  & adjust wiring station &       & 2: each tube on chamber assembly jig \\
& & & &\\

Relative azimutal        & $\pm 10$~mrad  & reject drift tube,    & local & 1: sample test/day \\
orientation of endplugs  &                & adjust wiring station &       & 2: each tube on chamber assembly jig \\
& & & &\\

Straightness    & insertion in jig       & reject drift tube & local & 1: sample test/day  \\
                & without difficulties   &                   &       & 2: each drift tube during chamber assembly \\
& & & &\\

Ground contact  & less than 100~m$\Omega$ & repeat laser welding & local & 1: sample test/day  \\
resistance      &                         &                      &       & 2: monitoring of selected tubes over time \\
& & & &\\
\hline\hline

\end{tabular}
\end{center}

\end{sidewaysfigure}
\clearpage


\begin{sidewaysfigure}
%\begin{table}[p]
\renewcommand{\arraystretch}{0.95}

\begin{center}
\noindent
{\bf Table~3:} Quality control tests for all drift tubes at the chamber production sites
\vspace{2mm}

\begin{tabular}{lllcl}

\hline\hline
& & & &\\
{\bf Test} & {\bf Acceptance criteria} & {\bf Reaction if failed} & {\bf Data base} & {\bf Comment} \\ [1mm]
\hline

& & & &\\
\multicolumn{5}{l}{\bf Drift tube} \\ [1mm]

Room temperature & $20\pm 2^\circ$~C & adjust & local & during tube tests \\
& & & &\\

Relative humidity      &                   &        & local & monitoring    \\
({\bf optional}) & & & &\\
& & & &\\

Temperature of tube & $20\pm 1^\circ$~C & adjust & local & during tube assembly \\
& & & &\\

Temperature of tube & known within $\pm 1^\circ$~C & repeat measurement & central & during wire tension measurement \\
& & & &\\

Wire tension             & within $\pm 5\% $      & reject drift tube & central  & 1: shortly after tube wiring \\
(oscillation frequency)  & of the nominal value   &                   &          & 2: after min.\ two months, before assembly \\
                         & at given temperature   & & &\\
& & & &\\

Wire location      & within $\pm 25~\mu$m of the & reject drift tube,  & central & sample test on day of wiring, \\
at the tube ends   & center of the endplug ref.  & inspect endplugs and  & & tube held as in assembly jig, \\
                   & surface in $y and $z$       & wiring station        & & incl.\ test of coaxiality of endplugs, \\
& & & & measurements at 0 and $180^\circ$   \\
& & & &\\

Pressure test at 3 bar & no obvious leaks  & reject drift tube,     & local & before leak test \\
overpressure           &                   & inspect endplugs,      & &  \\
                       &                   & adjust wiring station  & &  \\
& & & &\\

Leak rate at 2 bar & less than $10^{-8}$~bar~l/s & reject drift tube, &  central &   \\
overpressure       &                            & inspect endplugs,     & &  \\
& & adjust wiring station & &\\
& & & &\\

HV stability test: & less than 2~nA/m & reject drift tube,             & central  & with Ar:CO${}_2$ (93:7) at 3 ~bar \\
leakage current    &                  & inspect endplugs, tubes, wire  &          & and 3400~V ($1.6\times 10^5$ gas gain) \\
& & & &\\                                                                                                                  

HV stability test: & within $\pm 3\sigma$  & reject drift tube, & central   & with Ar:CO${}_2$ (93:7) at 3 bar \\
cosmic count rate  & of nominal value      & inspect endplugs, tube, wire   &  & and 3190~V ($4\times 10^4$ gas gain) \\
({\bf optional}) & & & & \\
& & & &\\

\hline\hline

\end{tabular}
\end{center}

%\end{table}
\end{sidewaysfigure}
\clearpage

The drift tube quality control tests are summarized in Tables~2 and 3. 
The test procedures are explained in the following.

\section{Wire Tension Measurement}
%
The gravitational sag of the wires has to be controlled within a tolerance of $\pm 10~\mu$m
in order to predict the wire position between the tube ends with sufficient accuracy.
The wire sag $s$ between the wire locators is related to the wire tension $T$ 
by $s=9.81\cdot \pi\rho d^2 L^2 / (32~T)$.

Measurement of the ground mode wire oscillation frequency $\nu$ determines the tension $T$ of the
wire with density $\rho$, diameter $d$ and length $L$
according to the relation $T=\pi \rho d^2 L^2 \nu^2$ and, with the above relations,
directly the wire sag independent of geometrical and material parameters of the wire:
$s= 9.81/ (32~\nu^2)$.

The wire tension is required to stay within $5\%$ of the nominal value at the nominal
temperature of $20\pm 1^\circ$~C. During tensioning and tension measurement, the
tube temperature has to be controlled and measured with this accuracy. The measured wire oscillation
frequency and temperature are stored in the central data base.

The instruments used for wire oscillation frequency measurement at the production sites
are summarized in Table~4. An example is shown in Figure~1.

\section{Wire Location Measurement}
%
Measurements of the wire locations at the tube ends in the two transverse coordinates
are performed with two methods (see Table~4).

\begin{enumerate}
\item X-ray measurement:
 
For the wire position measurement, the tube ends are held in a jig in the same way and the same azimutal orientation
as later in the chamber assembly jig. Reference wires with known distances are embedded in the V-block holding
the endplug. With two X-ray sources illuminating the tube under a stereo angle close to the endplug,
shadows of the sense and reference wires are projected
onto two X-ray CCD images (see Figures~1 and 2). Using the reference wire grid,
the $y$ and $z$ positions of the sense wire can be reconstructed with respect to the endplug reference surface
where it is supported on the jig with a resolution of $2~\mu$m. The measurement determines the wire position 
independent of the roundness of the endplug reference surface. 
A second measurement after rotating the tube by $180^\circ$ allows to test
if the wire is held correctly by the wire locator.

A wire location measurement station for series production is shown in Figure~4.

\item Electromagnetic pickup measurement:
 
Signals of an alternating current circulating through the sense wire is picked up by two coils on opposite sides
of the tube (see Figure~3). The difference in the signal amplitudes allows to determine the wire
displacement from the center in the plane of the coils with a resolution of $2~\mu$m. 
By rotating the tube on the support points on the endplug reference surface, the wire displacement
from the center of the reference surface in both transverse coordinates can be determined.                                          

The measurement setups are regularly recalibrated with a calibration tube.
Tubes with measured wire locations within $\pm 25~\mu$m of the center of the endplug reference surface
are accepted. 

For the module~0 chambers, the wire locations in all tubes will be measured. During
series production, the measurement of only a fraction of the tubes produced per day is required
to test the quality of the precision endplugs and the tube assembly tooling.

\section{Gas Pressure and Leak Test}
%
For the individual drift tubes in the chambers, the gas leak rate is required
to be below $1\cdot 10^{-8}$~bar~l/s at the nominal pressure of 3 bar
in order to prevent back diffusion and gas contamination. 
The direct detection of holes
in the tube walls by the manufacturer, e.g.\ with the eddy current method,
is too expensive. Therefore the whole drift tube including endplugs and tube
walls has to be leak tested. 

For this purpose, the drift tubes are fully enclosed in a container.
The drift tubes in the container are filled
with an Ar:CO${}_2$ gas mixture with helium admixture up to 3 bar overpressure
to perform the required pressure test at 1.5 times the nominal overpressure.
Subsequently, the argon or helium leak rate into the evacuated container
is measured at the nominal overpressure of 2 bar with a mass spectrometer of helium
leak detector (see Figures~7 and 8).

For many different tube lengths of the endcap chambers an alternative method
is also used. The leakage of the whole tube is measured with evacuated fixtures on the tube ends and
a fixture moveable along the tube wall using a helium leak detector (see Figure~9).

The gas leak test is the most time consuming part of the drift tube quality control.
Automatised leak test stands are prepared which measure the daily tube production
over night under computer control (see Figure~2 and Table~4). A large number of tubes is either
tested simultaneously in multi-tube containers or sequentially in many single-tube
containers (see Figure~8). In the automatised test stands, the leak test is
integrated with automatic wire tension measurement and leakage current measurement
for the high voltage stability test.


\section{High Voltage Stability Test}
%
Tests have shown that the leakage currents of good drift tubes are about





\renewcommand{\arraystretch}{1.05}
\begin{sidewaysfigure}

\noindent
{\bf Table~4:} Drift tube test equipment at the production sites
\vspace{2mm}

\begin{footnotesize}

\begin{tabular}{|l|l|l|l|l|l|l|} \hline\hline
{\bf Site} & {\bf Wire tension}      & {\bf Wire position} & {\bf Leak rate}    & {\bf HV test}           & {\bf HV test}  \\
           & {\bf (osz.\ frequency)} &                     & {\bf (whole tube)} & {\bf (leakage current)} & {\bf (cosmic rate)} &  \\ \hline

{\bf Freiburg} &   & excitation in B-field & Brandeis X-ray & leak detector with      & HV system with & yes \\
               &   &                       & system         & single-tube containers  & pA-meter       &     \\
\hline

{\bf LMU/MPI}   & CAEN SY502 meter,      & Brandeis X-ray  & pressure rise in evacuated       & 1~nA sensitivity & BNL preamp., \\
(accept.\ test) & excitation in B-field  & system, MPI jig & volume at endplug (8 tubes sim.) & HV system        & shaper       \\

{\bf NTU Athens} & CAEN SY502 meter,     & Brandeis X-ray  & leak detector,                & as Pavia &    & \\
                 & excitation in B-field & system          & single-tube container         & (single-tube) & \\
\hline

{\bf Univ.\ Athens} & \multicolumn{5}{c|}{as NTU Athens} \\
 & \multicolumn{6}{c|}{        (after module~0)}& \\ \hline

{\bf Thessaloniki} & excitation in B-field & & & CAEN SY127 (40 channels), & \\
(accept.\ test) & & & & & 1~nA sensitivity HV system & & \\ \hline

{\bf Frascati} & electrostatic excit.,      & electromagnetic, & Helium leak detector,      & CAEN SY546 (96 channel)     & yes \\
               & multi-channel system,      & as Pavia/Rome    & 60 single-tube containers   & 1~nA sensitivity HV system, &  \\
               & integration with leak test &                  &                            & integration with leak test   &  \\
\hline

{\bf Cosenza}  & CAEN SY502 meter,          & electromagnetic, & as Pavia,                  & CAEN SY546 (96 channel)      & \\
               & excitation in B-field      & as Pavia/Rome    & automatic control system   & 1~nA sensitivity HV system,  & \\
               & integration with leak test &                  &                            & integration with leak test   &  \\
\hline

{\bf Pavia}    & as Rome                    & electromagnetic  & Argon mass spectrometer,   & HV system (10 channels)   &  \\
               &                            & (EMMI)           & 10 single-tube containers  & with pA-meter,            &
               &                            &                  & (commercial system)        & integration with leak test   &  \\
\hline

{\bf Rome}     & excitation in B-field,     & electromagnetic  & as Frascati or Pavia,      & as Pavia & \\
               & multi-channel              & (EMMI)           &                            &          &  \\
\hline

{\bf NIKHEF}   & mechanical excitation,     & electromagnetic, & Helium leak detector,       & multi-channel HV system, & yes \\
               & piezo-electric measurement & as Pavia/Rome    & multi-tube container        & integration with leak test &  \\
\hline

{\bf Dubna}    & excitation in B-field, & Brandeis X-ray   & Helium mass spectrometer,       & CAEN SY546 (96 channel) & BNL preamp., \\
(also for MPI) & meter custom design    & system, MPI jig  & multi/single-tube containers    & 1~nA sensitivity HV system & shaper  \\
\hline

{\bf Protvino} & excitation in B-field, & Brandeis X-ray   & mass spectrometer &  &  \\
               & meter custom design    & system           &                   &  &  \\
\hline

{\bf Boston}   & excitation in B-field, & Brandeis X-ray   & Mass spectrometer,   & multi-channel HV system,   & yes \\
               & meter custom design    & system           & multi-tube container & integration with leak test &     \\
\hline

{\bf Michigan} & as Seattle             & electromagnetic, & Helium leak tester,         & multi-channel HV system  &   \\
               &                        & as Pavia/Rome    & evacuated volume at end-    &  & \\
               &                        &                  & plug and moving along tube  &  & \\
\hline

{\bf Seattle}  & excitation in B-field, & electromagnetic, & as Michigan  & as Michigan  &  \\
               & meter custom design    & as Pavia/Rome    &              &  &   \\
\hline\hline
\end{tabular}

\end{footnotesize}
\end{sidewaysfigure}
%
\clearpage

%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%

\chapter{Chamber Assembly}

\section{Assembly Room}
%
Spec, Clean room procedures



\section{Assembly Tooling}

Granite table

Jigging

painting of RASNIK elements

cleaning of chamber and jigging components, of glue surfaces (incl.drying)


\section{Glueing Procedures}
%
The following glues are used for chamber assembly:

\begin{itemize}  

\item For spacer assembly, glueing of tube layers to the spacer and
mounting of gas distribution bars:

Ciba Geigy Araldite 2014 (AW 139/ XB 5323) with low viscosity to
fill the large glue gaps with shrinkage $<1\%$, setting (usage) time of 40 minutes,
curing time of 3.5 (5) hours to achieve minimum shear strength of 1 (10)~N/mm${}^2$
at $23^\circ$~C on aluminum and a shelve time of 3 years at $18-25^\circ$~C.

The glue is applied with a manual glue dispenser with static mixer.
It will be cured for 12 hours during chamber assembly.

\item For glueing of tubes on tubes:

Ciba Geigy Araldite 2011 (AW 106/ HV 953U) with viscosity of $40-45$~Pa
after mixing at $23^\circ$~C,
setting (handling) time of 105 minutes in glue container and 90 minutes exposed to air,
curing time of 7 (10) hours
to achieve minimum shear strength of 1 (10)~N/mm${}^2$ at $23^\circ$~C
on aluminum and a shelve time
of 3 years at $18-25^\circ$~C.

The glue is applied in premixed form on a complete tube layer inserted in
the assembly combs using an automatic glue dispenser with a speed
of typically 20-30 minutes for a layer depending on chamber size.
which leaves enough reserve in case of problems. Up to 90 minutes
glue handling time can be accepted with the proper control of
out-of-plane deflections of tubes in the assembly process.

Good control of the amount and location of the glue distributed
on the tube layer by design of the glue dispenser minimises
effects of glue shrinkage and out-of-plane deflections of tubes
on the mechanical accuracy of the chambers.

The glue will be cured for 12 hours during chamber assembly.
Handling of the premixed glue and the automatic glue dispensers
is described in a {\bf Glueing Manual}.

\item For glueing of alignment platforms, Faraday cage mouting bars,
in-plane alignment monitor components, temperature and B-field sensors:

Ciba Geigy Araldite 2012 (AW 2104/ HW 2934) with viscosity as
Araldite 2011, setting (usage) time of 5 minutes, curing time of
20 (105) minutes to achieve minimum shear strength of 1 (10)~N/mm${}^2$
at $23^\circ$~C on aluminum and a shelve time of 3 years at $18-25^\circ$~C.

\end{itemize}

All surfaces glued must be cleaned with alcohol and dried before glueing
according to the glue handling specifications. This includes the components
of the spacer, the gas system, Faraday cages, on-chamber monitors and alignment
platforms.

The tubes are stored and transported in air-tight bags at all times
after cleaning by the manufacturor. The bags 
are only opened and packed inside the clean rooms for tube assembly and test
and for chamber assembly at the production sites.
The tubes are handled with plastic gloves only in order to avoid contamination.
If nevertheless tubes get contaminated by dust or grease etc.,
they have to be carefully cleaned
with alcohol without destroying the bar code and bending the tubes.

Details about the glueing processes during chamber assembly and the
associated quality assurance are described in the {\bf Chamber Assembly Manual}
and the {\bf Glueing Manual}.

For each glueing step, an aluminum test piece is glued simultaneously
from the same glue mixture as used for the
chamber assembly to evaluate independently the proper
curing of the glue. The glue on the chamber is inspected after the
nominal curing time. If the glue should not cure as required even after
an extended time period, the tube layer or even the whole chamber have to be discarded
depending on the assembly step.

\section{Qualification and Training of Personell}
%
The assembly of a chamber is carried out by 3 {\bf Operators} as described
in the {\bf Chamber Assembly Manual}.

{\bf Operator 3} coordinates the work in the assembly room, ensures that
all assembly and QA/QC steps are performed correctly and operates the
monitors for assembly control with the help of the {\bf Assembly Control Program}.
He also operates the crane during the assembly procedure.

The {\bf Production Manager} (phycicist) supervises the whole chamber assembly process.
He evaluates the monitoring data and has to be consulted when alarms occur.
Critical steps have to be approved by him
as described in the {\bf Assembly Control Plan}.
Chamber construction must not continue without approval by the responsible person
indicated.

\section{Preparation of Components}
%
Check of quality control documents (supplier and local), cleaning,
labelling.


 chamber construction in the assembly room.

\begin{itemize}

\item[1.1] Combs ($z$-distances and height in $y$ of V-grooves,
$z$- and $y$-alignment of comb lines) and sphere support towers (height with
different interfaces) measured at each site
before module~0 construction.
\hfill $\longrightarrow$ DB

\item[1.2] Mark readout (RO) and high-voltage (HV) side on assembly table.

Mark chamber coordinate system on granite table.

Mark sequential numbers of tube insertion on both end combs.

Mark reference side on assembly table.

Mark sphere support towers with numbers, mark towers with fixed sphere positions.

Mark tower interfaces corresponding to towers.

Mark identifiers of force compensation supports on granite table,
corresponding with DB.

Mark location of transfer blocks for alignment platform positioning on combs.

Mark chamber identifier (ATLAS numbering scheme) on RO and HV cross plate outer surfaces
and on protective covers.

\item[1.3] Clean assembly room regularly.

Allways wear clean room clothes in the assembly room.

Use only materials acceptable for clean rooms in the assembly room.

\item[1.4] Regular control of accuracy and alignment of the assembly jigging:

\begin{itemize}
\item[1.4.1] Height in $y$ and $z$-distances of V-grooves of all combs
in the setup on the assembly table before start of production.
\hfill $\longrightarrow$ DB

\item[1.4.2] Relative alignment of combs on the assembly table before start of
production.

\item[1.4.3] Height of the sphere support towers with the different interfaces
on a coordinate measuring machine before start of production.
\hfill $\longrightarrow$ DB

\item[1.4.4] Height of V-grooves of end combs: for every tube layer
with endplug height measurements (see 2.7.11).
\hfill $\longrightarrow$ DB

\item[1.4.5] Relative alignment of comb lines: before start of production and
in 1/2 year intervals (e.g.\ laser-CCD instrument from Brandeis).
\hfill $\longrightarrow$ DB

\item[1.4.6] $z$-distances of V-grooves of end combs: in 1 year intervals (with interferometer;
to be organized between the collaborating institutes).
\hfill $\longrightarrow$ DB

\item[1.4.7] Height of individual sphere support towers with different interfaces: for every tube layer
with sphere monitors (relative to zero-readings; see 2.3.1).
\hfill $\longrightarrow$ DB

\item[1.4.8] Height differences between sphere support towers (interfaces): for every tube layer
with in-plane alignment system (see 2.3.1).
\hfill $\longrightarrow$ DB

\end{itemize}

\item[1.5]  Regularly clean jigging components and check for possible corrosion.

\item[1.6] Quality control of chamber components before storage in the assembly room
according to specifications.

\item[1.7] Store all chamber materials and jigging components in the
assembly room at least 12 hours before use to adjust to the assembly temperature
of $20^\circ$~C (tubes, spacer parts, alignment platforms, gas system components,
monitoring components, sphere tower interfaces).

\item[1.8]  Clean all components and materials before storing them in the clean room.

\item[1.9] Install gas manifolds and gas distribution bars on their assembly jigs.

Test for leak tightness and gas flow.

\item[1.10] Mark readout (RO) and high-voltage (HV) side cross plates.

Mark orientation to top multilayer on all cross plates and long beams.

Mark identifiers of the in-plane alignment, cross plate sag and sphere monitors
on the spacer corresponding with DB.

Mark locations of mask, lens and CCD of permanent and temporary RASNIK monitors 
on cross plates and long beams.

\item[1.11] Install and adjust sag compensation system on long beams.

\item[1.12] Mount sphere holders with spheres and sphere monitors on the cross plates.

Special attention: ensure stable fixation and positioning in $y$ within tolerances (glue gap).

\item[1.13] Mount cross plate sag monitors temporarily on the two outer cross plates.

\begin{itemize}
\item[1.13.1] Adjust RASNIK cross plate sag monitors: sharp, analyzable image of center of mask.

Comment: Requires proper relative orientation of mask and CCD of RASNIK monitors
(see {\bf RASNIK Monitor Manual}).
\end{itemize}

\item[1.14] Install in-plane RASNIK monitor components on cross plates.

\item[1.15] Video tape all steps of module~0 construction at all production sites.

\item[1.16] Video tape horizontal glue gaps with illumination from below,
video tape glue distribution with camera on moving glue dispenser for online/offline
control???
\end{itemize}


\section{Optical Monitoring}
%
Devices and use.

\section{Glue Handling}
%
Glue Manual, shrinkage.

\section{Assembly Control Plan}
%
The {\bf Assembly Control Plan} describes the
detailed QA/QC steps for the construction of a standard barrel MDT chamber.

The assembly plan is a guideline for the preparation
work check lists and for the implementation of the QA/QC procedures
in an {\bf Assembly Control Program} which allows to verify all essential
assembly steps, controls and analyses the monitor readings, stores them
in the local {\bf Production Data Base} as required by the {\bf Assembly
Control Plan}, and issues alarms if parameters are out of tolerances.

For a detailed descriptions of each work step see
the {\bf Chamber Assembly Manual} and
associated documents for specific components and procedures 
(monitoring systems, gas system, glueing procedure).


\section{Assembly Control Software}



%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%

\chapter{Chamber Test}


\begin{sidewaysfigure}
%\begin{table}[p]
\renewcommand{\arraystretch}{0.95}

\begin{center}
\noindent
{\bf Table~5:} Quality control measurements during chamber assembly.
\vspace{2mm}

\begin{tabular}{lllcl}

\hline\hline
& & & &\\
{\bf Test} & {\bf Acceptance criteria} & {\bf Reaction if failed} & {\bf Data base} & {\bf Comment} \\ [1mm]
\hline

& & & &\\
\multicolumn{5}{l}{\bf Environment} \\ [1mm]

Room temperature       & $20\pm 1~\circ$~C & adjust & local & before glueing \\
& & & &\\

Relative humidity      & $50\pm 10~\%$     & adjust & local & before glueing \\
& & & &\\

Atmospheric pressure   &                   &        & local & monitoring     \\
({\bf optional}) & & & &\\
& & & &\\

Temperature of chamber & $20\pm 0.5^\circ$~C & adjust & local & before glueing \\
& & & &\\

Temperature of jigging & $20\pm 0.5^\circ$~C & adjust & local & before glueing \\
& & & &\\

Temperature difference & $<0.2^\circ$~C & adjust & local & before glueing \\
betw.\ chamber and jig & & & &\\
\hline

& & & &\\
\multicolumn{5}{l}{\bf Spacer assembly} \\ [1mm]

Glue gaps between tube layer & $200-1000~\mu$m  & adjust & local & both orientations of cross plates \\
on combs and cross plates    &                  &        &       & around $z$-axis                  \\
& & & &\\
\hline

& & & &\\
\multicolumn{5}{l}{\bf On-chamber gas system} \\ [1mm]

Leak rate  & less than $10^{-8}$~bar~l/s  & repair & local & of preassembled gas manifolds \\
& & & &\\

Flow rate/tube  & to be specified  & repair & & for preassembled gas manifolds \\
& & & &\\
\hline\hline

\end{tabular}
\end{center}

%\end{table}
\end{sidewaysfigure}
\clearpage


\begin{sidewaysfigure}
%\begin{table}[p]
\renewcommand{\arraystretch}{0.95}

\begin{center}
\noindent
{\bf Table~6:} Quality control measurements during chamber assembly (cont.)
\vspace{2mm}

\begin{tabular}{lllcl}

\hline\hline
& & & &\\
{\bf Test} & {\bf Acceptance criteria} & {\bf Reaction if failed} & {\bf Data base} & {\bf Comment} \\ [1mm]
\hline

& & & &\\
\multicolumn{5}{l}{\bf Assembly of tube layers} \\ [1mm]

Vacuum suction  & at nominal value & adjust & local & tube positioning on combs during glueing  \\
underpressure   & & & &\\
& & & &\\

Horizontal gaps between tubes  & not more than two adjacent     & relocate drift tubes &       & before glueing \\
                               & tube walls touching,           & & &\\
                               & no adjacent endplugs touching  & & &\\
& & & &\\

Vertical position of endplug   & $\pm 10~\mu$m of nominal value & relocate drift tubes & local & before glueing \\
reference surfaces             &                                & & &\\
& & & &\\

Sphere locations               & $\pm 10~\mu$m of nominal value & adjust               & local & before glueing, \\
& & & & with sphere and in-plane monitors \\
& & & &\\

Outer cross plate sags         & $\pm 10~\mu$m                  & adjust               & local & before glueing, \\
on the assembly table          & & & & with temporary cross plate monitors \\
& & & &\\

Middle cross plate sag         & $\pm 20~\mu$m                  & adjust               & local & before glueing, \\
on the assembly table          & & & & with temporary cross plate monitors \\
& & & &\\
\hline\hline

\end{tabular}
\end{center}

%\end{table}
\end{sidewaysfigure}
\clearpage


\begin{sidewaysfigure}
%\begin{table}[p]
\renewcommand{\arraystretch}{0.95}

\begin{center}
\noindent
{\bf Table~7:} Quality control tests of assembled chambers at the production sites
\vspace{2mm}

\begin{tabular}{lllcl}

\hline\hline
& & & &\\
{\bf Test} & {\bf Acceptance criteria} & {\bf Reaction if failed} & {\bf Data base} & {\bf Comment} \\ [1mm]
\hline

& & & &\\
\multicolumn{5}{l}{\bf Mechanical Tests} \\ [1mm]

Sag of chamber &  & store data & central & $y$ readings of  \\
with kinematical supports & & & & in-plane monitors \\
before sag compensation   & & & &  \\
& & & &\\

Sag of chamber            & within $\pm 20~\mu$  & adjust sag compensation  & central & $y$ readings of  \\
on kinematical supports & of wire sag          & until tolerance reached, & & in-plane monitors \\
after sag compensation    &                      & store data               & &  \\
& & & &\\

Deformation of cross plates  & $<20~\mu$m  & store data & central & with temporary cross \\
on kinematical support       & & &                                & plate sag monitors \\
({\bf optional}) & & & &\\

& & & &\\
\hline\hline

\end{tabular}
\end{center}
\hfill

%\end{table}
\end{sidewaysfigure}
\clearpage


\begin{sidewaysfigure}
%\begin{table}[p]
\renewcommand{\arraystretch}{0.95}

\begin{center}
\noindent
{\bf Table~8:} Quality control tests of assembled chambers at the production sites (cont.)
\vspace{2mm}

\begin{tabular}{lllcl}

\hline\hline
& & & &\\
{\bf Test} & {\bf Acceptance criteria} & {\bf Reaction if failed} & {\bf Data base} & {\bf Comment} \\ [1mm]
\hline

& & & &\\
\multicolumn{5}{l}{\bf Operation Tests} \\ [1mm]

Pressure test & test done,        & repair gas manifold,   & central  & before leak test  \\
at 4 bar      & no obvious leaks  & repair/disconnect      &          &                   \\
              &                   & faulty tubes, store ID &          &                   \\
& & & &\\

Leak rate & less than $2\times 10^{-8}$~bar~l/s per tube & repair gas manifold, & central &        \\
at 3 bar  &                                              & repair/disconnect    &         &        \\
          &                                              & faulty tubes, store ID &       &        \\
& & & &\\

HV stability:   & less than 5~nA/channel & replace electronics  & central & with installed electronics baords,  \\
leakage current &                        & boards; identify,    &         & with baseline gas at 3 bar \\
                &                        & sputter/disconnect   &         & and nominal and $5\times$ nominal  \\
                &                        & faulty drift tubes,  &         & gas gain                         \\
                &                        & store ID             & &\\
& & & &\\

HV stability:   & less than $5\times$    & identify noisy       & central & with installed electronics boards,  \\
cosmic count rate & nominal value        & channels,            &         & with baseline gas at 3 bar \\
({\bf optional})  &                        & store ID             &         & and nominal gas gain  \\
& & & &\\

Operation in    & evaluation of performance: & make chamber     & central & with test electronics,  \\
cosmic ray test & noise level, efficiency,   & operational,     &         & with baseline gas at 3 bar \\
stand           & random rate, max.\ drift time,  & store ID of      &         & and nominal gas gain       \\
                & resolution vs.\ $x$, uniformity  & faulty tubes     & &\\
                & local wire displacements   & & &\\
& & & &\\

Wire location   & no systematic deviations   & store wire location    & central & track reconstruction \\
measurement     & from expected wire grid    & data and chamber ID,   &         & in cosmic ray tower  \\
with cosmic rays&                            & adjust assembly tooling&         &  \\
({\bf optional}) &                           & in case of deviations  & &\\
& & & &\\
\hline\hline

\end{tabular}
\end{center}
\hfill

%\end{table}
\end{sidewaysfigure}
\clearpage


\begin{sidewaysfigure}
%\begin{table}[p]
\renewcommand{\arraystretch}{0.95}

\begin{center}
\noindent
{\bf Table~9:} Quality control tests of assembled chambers during storage and at CERN
\vspace{2mm}

\begin{tabular}{lllcl}

\hline\hline
& & & &\\
{\bf Test} & {\bf Acceptance criteria} & {\bf Reaction on failure} & {\bf Data base} & {\bf Comment} \\ [1mm]
\hline

& & & &\\
Visual     & no visible damage  & perform possible      &   & acceptance test after transport  \\
inspection &                    & repairs, mark chamber &   & to CERN  \\                                                                     
           &                    & for X-ray tomograph   &   &          \\
           &                    & and full leak test    &   &          \\
& & & &\\

Leak rate & less than $2\times 10^{-8}$~bar~l/s per tube & repair gas manifold, & central & 1: full leak test for one chamber per \\
at 3 bar  &                                              & repair/disconnect    &         & transport to CERN (acceptance test)  \\
          &                                              & faulty tubes, store ID &       & or if visible damage of chamber \\
          &                                              &                        &       & 2: monitoring of pressure (at constant \\
          &                                              &                        &       & temperature) over storage time \\
& & & &\\

Wire location   & $\pm 20~\mu$m rms in $y$ and $z$ & store wire location & central & 1: sample test/production site \\
measurement with& with respect to        & data and chamber ID,          &         & 2: for chambers with expected  \\
X-ray tomograph & expected wire grid     & adjust assembly tooling&         & \hphantom{2:} mechanical problems \\
(incl.\ location&                        & in case of deviations, &         &                         \\
of wire on the  &                        & measure chambers since &         &                         \\
alignm.\ platforms) &                    & problem first detected &         &                         \\
& & & &\\

HV stability:   & less than 5~nA/channel & replace electronics  & central & after mounting of final electronics, \\
leakage current &                        & boards; identify,    &         & with baseline gas at 3 bar and            \\
                &                        & disconnect faulty    &         & nominal and $2\times$ nominal  \\
                &                        & tubes, store ID      &         & gas gain     \\
& & & &\\
Operating test  & evaluation of performance: & replace electronics, & local   & after mounting of final electronics, \\
                & pulser test (correct       & make chamber         &         & with baseline gas at 3 bar           \\
                & connections), signals      & operational          &         & and nominal operating conditions     \\
                & from all channels, noise   &                      &         &                                      \\
                & level, random rate, uniformity &                  &         &                                      \\
& & & &\\

Wire tension      & within $\pm 5\%$      & store data,               & central & for one chamber/production site  \\
(osc.\ frequency) & of the nominal value  & notify production sites,  &         & at regular intervals over storage time \\
                  & at given temperature  & measure other chambers    &         & (temperature meas.\ to $\pm 1^\circ$~C) \\
& & & &\\

Tube ground       & less than 100~m$\Omega$  & store data,               & central & for one chamber/production site  \\
contact resistance &                         & notify production sites,  &         & at regular intervals over        \\
                  &                          & measure other chambers    &         & storage time                     \\
& & & &\\

\hline\hline

\end{tabular}
\end{center}
\hfill

%\end{table}
\end{sidewaysfigure}
\clearpage

\section{Chamber Test Program at the Production Sites}
%
\begin{itemize}

\item[1] Install chamber in leak, high voltage and cosmic ray test stand
with kinematic supports as in ATLAS.

\item[2] Chamber pressure test.

\begin{itemize}
\item[2.1] Connect gas supplies.

Fill chamber with Argon or $N_2$ to 4 bar pressure.

Identify and repair obvious leaks, disconnect faulty tubes.
Store ID of faulty/repaired tubes in data base (central).
\hfill $\longrightarrow$ DB

If no obvious leaks, reduce gas pressure to 3 bar.
\end{itemize}

\item[3] Chamber leak test.

\begin{itemize}
\item[3.1] Monitor changes of gas pressure and temperature difference
of the chamber with respect to a reference volume with a differential manometer
in intervals of 12 hours over several (2-10) days depending on
sensitivity of the temperature and pressure measurements.

\item[3.2] Calculate leak rate limit from temperature-corrected
pressure drop in the chamber.

Stop when required leak rate limit is reached.

If required leak rate limit is not reached after the time period expected
from the measuring sensitivity:
identify and repair leaks, disconnect faulty tubes. Repeat leak test from 3.1.

After successful leak test: store leak rate limit in data base (central).
\hfill $\longrightarrow$ DB
\end{itemize}                                                                                    

\item[4] After start of leak test with no obvious leaks detected:
Install hedgehog boards (already individually tested).

Boards are installed properly cleaned.

\item[5] Install mezzanine cards with test electronics; connect to DAQ system.

\item[7] Store all optical monitor and temperature sensor readings in data base (local).
\hfill $\longrightarrow$ DB

Store longitudinal in-plane monitor $y$-readings (gravitational sags of the chamber)
before sag adjustment in data base (central).
\hfill $\longrightarrow$ DB

\item[8] Compensate sags of the chamber with the sag compensation systems of the
two long beams.

\item[9] Store all optical monitor and temperature sensor readings in data base (local).
\hfill $\longrightarrow$ DB

Store longitudinal in-plane monitor $y$-readings (gravitational sags of the chamber)
after sag adjustment in data base (central).
\hfill $\longrightarrow$ DB

Readout all optical monitors and temperature sensors on the chamber
continuously during chamber tests.

\item[10] High voltage stability and operating test with installed readout electronics.

\begin{itemize}
\item[10.1] Fill chamber with baseline gas to 3 bar.

Operate chamber at baseline operating point within tolerances.

\item[10.2] Document gas composition and electronics settings in data base (local).
\hfill $\longrightarrow$ DB

\item[10.3] Monitor temperature, gas pressure, high voltage and chamber currents at each step.

\item[10.4] Turn on high voltage: start at 1~kV below operating voltage, ramp up in 100~V steps
until voltage corresponding to a gas gain of $10^5$ is reached.

Wait at each step until chamber currents drop below 5~nA/tube.

If current does not drop: identify faulty channels.

If caused by electronics: replace boards.

If caused by drift tubes: disconnect tubes.

Record disconnected tube IDs in data base (central).
\hfill $\longrightarrow$ DB

\item[10.5] At the nominal operating voltage: identify channels with more than
$5\times$ the expected cosmic count rate.

Record noisy channel IDs in data base (central).
\hfill $\longrightarrow$ DB

\item[10.6] Sputter faulty tubes due to leakage current.

Record sputtered tube IDs in data base (central).
\hfill $\longrightarrow$ DB

\item[10.7] Repeat HV test from 10.4.

Record faulty tube IDs in data base (central).
\hfill $\longrightarrow$ DB

Store chamber currents and cosmic count rates at operating voltage and at voltage
corresponding to a gas gain of $10^5$ in data base with temperature, gas pressure and
high voltage values (local).
\hfill $\longrightarrow$ DB
\end{itemize}                                                                                    

\item[11] Operation of chamber
in cosmic ray test stand at baseline operating point
for at least one week.

\begin{itemize}

\item[11.1] Monitor temperature, high voltage, gas pressure, chamber currents, count rates
and optical monitor readings continuously.

\item[11.2] Evaluation of chamber performance.

Sensitive parameters among others:
noise level, tube efficiency, random rate, minimum and maximum drift time,
local wire displacements, position resolution as function of $x$, uniformity.

Store in data base (local).
\hfill $\longrightarrow$ DB

Make chamber operational.

\item[11.3] Optional: Reconstruction of global wire locations with reconstruction of cosmic ray
tracks in tower of three chambers.
\hfill $\longrightarrow$ DB
\end{itemize}

\item[12] Store optical monitor and temperature sensor readings on the chamber
at the end of the chamber tests.
\hfill $\longrightarrow$ DB

\item[13] Keep chamber filled and sealed with baseline gas at 3 bar during all future transport
and storage. 

Monitor temperature and gas pressure of the chamber.
\end{itemize}



\section{Chamber Test Program at CERN}
%
\begin{itemize}

\item[1] Acceptance test of chamber after arrival in the storage area at CERN:

\begin{itemize}
\item[1.1] Chambers are installed on their kinematical supports during storage.

\item[1.2] Store optical monitor, temperature sensor and gas pressure readings
on the chamber (after first arrival and after every future transport).
\hfill $\longrightarrow$ DB

\item[1.3] Visual inspection of each chamber for visible
damage; flag chambers for X-ray tomograph measurement and full leak test.

\item[1.4] Leak test at 3 bar (as at the production sites)
of one chamber per transport  
(acceptance test) or if incidences during transport or visible damage.

Store leak rate limit in data base (central).
\hfill $\longrightarrow$ DB
\end{itemize}

\item[2] Wire location measurement with the X-ray tomograph at CERN:

\begin{itemize}
\item routinely for selected chambers as soon as possible after arrival of a transport 
to provide feedback to the production sites,

\item for chambers flagged with problems discovered during construction.

\item for chambers with visible damage observed after transport.

\end{itemize}

\begin{itemize}
\item[2.1] Install chamber in X-ray tomograph
on kinematical supports in horizontal orientation closest to the orientation in ATLAS.

\begin{itemize}
\item[2.1.1] Handling and transport of chambers at CERN only with supervisor nominated by production site present.

\item[2.1.2] Transport of chamber in special transport frame provided by production site.

Handling of chamber with tooling provided by production sites.
\end{itemize}

\item[2.2] Monitor optical monitor and temperature sensor readings on the chamber
during measurements in X-ray tomograph.
\hfill {$\longrightarrow$ DB}

\item[2.3] X-ray scans: close to each end of the chamber (including wires on alignment platforms) and at the ends
of cut outs. 

Repeat each scan to check reproducibility.

Store reconstructed wire coordinates ($y$ and $z$ at $x$-position of scan) for each scan
in data base with temperature and optical monitor readings (central).
\hfill $\longrightarrow$ DB
\end{itemize}

\item[3] Monitor gas pressure (with temperature) of the chamber regularly during storage time.

Store data in data base (local).
\hfill $\longrightarrow$ DB

\item[4] High-voltage and operating test after installation of final readout electronics
(already tested individually):

\begin{itemize}
\item[4.1] Document electronics settings in data base.
\hfill $\longrightarrow$ DB

\item[4.2] Monitor temperature, gas pressure, high voltage and chamber currents at each step.

\item[4.3] Turn on high voltage: start at 1~kV below operating voltage, ramp up in 100~V steps
until voltage corresponding to a gas gain of $10^5$ is reached.

Wait at each step until chamber currents drop below 5~nA/tube.

If current does not drop: identify faulty channels.

If caused by electronics: replace boards.

If caused by drift tubes: disconnect tubes.

Record disconnected tube IDs in data base (central).
\hfill $\longrightarrow$ DB

\item[4.4] Store chamber currents at operating voltage and at voltage
corresponding to a gas gain of $10^5$ in data base with temperature, gas pressure and
high voltage values (local).
\hfill $\longrightarrow$ DB

\item[4.5] Operating test of final electronics setup:

Pulser test of connections, signals in all channels, random rate,
evaluation of noise level and uniformity.

Store in data base (local).
\hfill $\longrightarrow$ DB

Make chamber operational.
\end{itemize}                                                                                    

\item[5] Store optical monitor and temperature sensor readings on the chamber
before transport to ATLAS cavern for detector installation (central).
\hfill $\longrightarrow$ DB

\end{itemize}



\section{The X-ray Tomograph}

%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%

\chapter{Chamber Transport and Storage}
%
Chambers are transported and stored under the following conditions:

\begin{itemize}  

\item The chambers are transported and stored with
Faraday cages (protection of the endplugs) and protective covers
(protection of the tubes) installed.

\item The chambers are transported and stored suspended on their
kinematical supports in a special frame inside a closed container.

\item After test at the production sites, the chambers are kept filled
with the baseline gas at 3 bar during all further transport and storage.

\item The chambers are enclosed in an air-tight plastic bag containing
dehumidifier bags.

\item The temperature of the chambers is monitored during transport and storage.
It must not be outside the range $10-30^\circ$~C. Temperature gradients
on the chamber must not be larger than $10^\circ$~C.

\item Shocks are monitored during transports to CERN.

\end{itemize}


\section{Local Chamber Storage and Transport to CERN}
%

\begin{itemize}
\item[1] Dismount test electronics (mezzanine cards only).

\item[2] Install chamber in local storage and transport frame.

\item[3] Store all optical monitor and temperature sensor readings after installation
in transport frame.
\hfill $\longrightarrow$ DB

\item[4] Chamber stays filled with baseline gas at 3 bar during transport and storage.

\item[5] Enclose chamber air-tight in plastic bag.

\item[6] Monitor temperature and humidity in storage room.
Protect chambers from temperature gradients.

\item[7] Monitor gas pressure during storage with cheap manometer on the chamber.
\hfill $\longrightarrow$ DB

\item[8] Store optical monitor, temperature sensor and gas pressure readings
before transport to CERN.
\hfill $\longrightarrow$ DB

\item[9] Transport, load, unload chambers according to handling instructions
(only with certified supervisor present).

Monitor temperature on the chamber and record shocks during transport.

\end{itemize}

\section{Chamber Transport and Storage at CERN}

\begin{itemize}

\item[1] Transport chamber to storage area at CERN.
Load, unload chamber according to handling instructions
(only with certified supervisor present).

Transport in transport frame.

\item[2] Store chamber in transport frame.

Store all optical monitor and temperature sensor readings
immediately after installation of chamber in storage area.\hfill \hbox to 2cm{\hfill $\longrightarrow$ DB}

\item[3] Enclose chamber air-tight in plastic bag during storage and transport.

\item[4] Leak test of the chamber with the baseline gas at 3 bar
immediately after installation in the storage area (as 10.8).

\item[5] Monitor temperature and humidity in storage room.
Protect chambers from temperature gradients.

\item[6] Monitor gas pressure during storage with the cheap manometer on the chamber.

\hfill $\longrightarrow$ DB

\item[7] After arrival of final electronics boards: install on stored chambers and
connect to DAQ.

\item[8] High-voltage and operating test with installed electronics boards (as 10.9).

\item[9] Store all optical monitor and temperature sensor readings
before transport to ATLAS cavern for detector installation.
\hfill $\longrightarrow$ DB

\end{itemize}

%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
\clearpage


\end{document}
