TIBTIDNotes/TIBTIDIntNote/IntegrationProcedures.tex

\section{Integration Procedures}
\label{sec:Procedures}
TIB and TID have different integration procedure, each one being optimised
for the geometry and a logical sequence of installation and test of components. 

In this section the operations which are required to assemble a TIB shell and a TID 
ring will be listed  and described in details separatelly for the two subdetectors. 
The various tests performed during the integration will just be mentioned among the
other steps in the sequence of operations: a deeper discussion will be done 
in section \ref{sec:Tests}.

For TIB  and TID the integration process starts with the basic mechanical structure, 
therefore respectivelly with a shell and a ring. This  carbon fiber supporting structure has already
being equipped with  cooling pipes and the precision mounting ledges 
have been already glued; all parts have passed a quality assurance test with accurate measurements
of the precision parts and cooling test have been performed for the cooling circuits. 

\subsection{TIB Integration Procedures}

To allow for a practical 
and safe handling of the structure during the integration, the shell is mounted, via an aluminum
support frame which minimizes the mechanical stresses, 
onto an integration bench. The bench allow to rotate the shell around the horizontally placed 
cylindrical axis.
In this way all the internal and external strings can be 
positioned in an optimal way for components mounting. The structure support frame holds also a
number of plastic boxes which are used to temporary store the analog optohybrids fibres and their 
connectors allowing for their accessibility during the various tests.
To identify each string during the shell integration bar code stickers are temporary glued
on the structure. The string sticker is read and send to the integration database interface program
before each mounting operation.\\
A picture of a Layer 4 mechanical structure mounted on the integration bench is shown in Fig.~\ref{fig:bench}.

\begin{figure}[!htb]
\begin{center}
  \includegraphics[width=0.85\textwidth]{Figs/bench.pdf}
\end{center}
\caption{A shell carbon fiber structure mounted on the integration bench. The cooling pipes
and ledges of inner part of the shell are visible.}
\label{fig:bench}       % Give a unique label
\end{figure}


\subsubsection{TIB Control Ring Preparation}
Once the shell has been mounted on the integration bench the next operation is the preparation 
of the Control Ring cables.
As described in section \ref{fig:ctrlring} the readout clock, 
trigger and slow control signals are distributed to the
detector modules via a token ring structured system mounted on the shells. Each TIB layer is
served by different Control Rings whose dimensions, in terms of modules, depend on the layer position.
For example Layer one and two, which are equipped with 
double sided modules, have control rings of 3 to 5
strings, while Layer three and four have 13 to 15 single sided strings.\\
The control ring boards (DOHM and AUX) are located on a carbon fiber plate mounted just above the modules on the
external part of the shell (see Fig. \ref{fig:dohm}). A carbon fiber cover of the same dimensions
of the plate close the control ring from above. An aluminum sheet has been glued 
both on the plate and the cover to protect the module from possible electrical interference. When
monted this aluminum sheet is connected to the cooling manifold ground.

\begin{figure}[!htb]
\begin{center}
  \includegraphics[width=0.60\textwidth]{Figs/dohm.pdf}
\end{center}
\caption{A DOHM and an AUX (the smaller board) with control ring cables connected and mounted on a
layer 3 shell.}
\label{fig:dohm}       % Give a unique label
\end{figure}

As can be seen in Fig.~\ref{fig:dohm}, due to the variable number of strings connected and their 
different positions with respect to the support
mechanics and cooling, each control cable have a different length and shape and
should be tailored in-situ to minimize the path satisfying all the mechanical constraints.
To avoid damages the control cable preparation should be done when the 
modules are not yet installed on the
structure. The control cable preparation has to be done very carefully to
avoid mechanical interference with the services (cables, fibers and pipes)
that share the narrow space on the shell flange 
(20mm in the z direction and 6mm in the radial one).?????????????????????????????
When the control ring has been cabled it is dismounted from the structure 
to proceed with AOH and module installation. \\
For layer three and four the part of the control cables
which is not protected by the carbon fiber plate
is shielded using a thin Aluminum foil.

\subsubsection{Analog Opto Hybrid Installation on Shells}
The small AOH board ($3\times 2.2 cm^2$) 
is simply screwed to a C-shaped ledge which is directly glued on the string cooling 
pipes. Due to mechanical constraints the
fibers, and their connectors, should be carefully routed to the outside of the shell through a
number of ledges, holes and pipes keeping 
them as close as possible to the carbon fiber structure surface to which they are finally fixed 
using kapton strips. The part of the pig-tail fibers which is not housed on the shell
is temporary stored in the plastic
boxes fixed to the shell support frame. Their connectors are inserted into
optical plugs which
ease the many connect-disconnect operations to be done during the tests.\\
Since the optical fibers are quite fragile they have been
protected when they cross the most critical points. 
For example at the
shell flange, where the fibers should turn at 90$^\circ$ together with 
all the other services, 
they are grouped together and covered by a thin silicon rubber spiral (see Fig. \ref{fig:spiraline}). 
This procedure resulted in very reliable protection since only 4 fibres out of 
6984 was found broken at the end of TIB integration.
A layer 2 shell with AOH mounted on is shown in Fig.~\ref{fig:aoh}.

\begin{figure}[!htb]
\begin{center}
  \includegraphics[width=0.60\textwidth]{Figs/aoh.pdf}
\end{center}
\caption{A layer 2 shell with AOH mounted. The optical fiber pig-tails are also visible.}
\label{fig:aoh}       % Give a unique label
\end{figure}

\begin{figure}[!htb]
\begin{center}
  \includegraphics[width=0.60\textwidth]{Figs/spiraline2.pdf}
\end{center}
\caption{Group of optical fibers protected by siliconic ruber spirals at the flange exit.}
\label{fig:spiraline}       % Give a unique label
\end{figure}

Since the AOH are powered by the module kapton tail they cannot be easily tested before the
modules are installed. This was a source of concerns when the integration has started: the 
operation of changing a broken AOH when the modules are already installed requires dismounting
the entire string with the result of a considerable increase of the risk of damage to the 
mounted objects. The number of AOH that should be replaced was anyway very small at the level
of one per shell.


\subsubsection{Shell mother Cable Installation}
The Mother Cables are inserted into the structure when the AOH have been mounted and the optical
fibers fixed to the shell and protected. This procedure is in some cases complicated by mechanical 
constraints at the level of the shell front flange, where the mother cables are entered in the shell, 
and cooling manifolds. When the Mother Cables are inserted they 
are connected to the power cables (medusa cables) which are temporary fixed to the shell supporting 
frame. \\
The 'medusa cables' are multi-strand cables with each conductor separatly insulated. 
This cable characteristic helps in efficiently use the very limited available space on the TIB 
front flange allowing to 'distribute' the cable among the other services.  \\
To make the control ring redundancy properly working each mother cable has to be provided with a
CCU whose address is in a fixed order with respect to its position in the token ring. This 
position depends on how the control ring has been cabled, so this information
has to be taken in mind when the Mother Cables are inserted into the structure.\\ 

\subsubsection{Module Mounting}\label{sect:tibmodules}
Both single and double sided modules are mounted on the shell by hand. 
They are fixed on two precision ledges: one supports the module below the front-end
hybrid and the other below the carbon fiber frame at the opposite end. 
The ledges precisely define the module position and also, being in contact with the cooling pipes,
act as heath sink for the front-end hybrid and sensor generated power. 
The shape of the ledges is different for the single sided and for the two kind 
of double-sided modules,
reflecting, in this latter case, the two different orientations of the "stereo" side of the module. 
Each ledge has two threaded holes (M1 screw type); one of them is concentric with a 
2 mm diameter socket
acting as a slot for the module precision aluminum inset which fixes the detector
position. The socket has been precisely drilled with respect to the ledge edges which 
in turns are the reference position for the precision mask used to glue them on the "shell".
All kind of modules have an aluminum pin glued on the carbon fiber frame at the hybrid end
and an aluminum U-shaped slot glued at the module opposite end. This two module insets,
together with the two ledge sockets and a pin to be inserted into the U-shaped slots, 
define the module position with respect to the shell.\\
Before mounting a module on the shell the structure is rotated to horizontally place
the corresponding string. Then the string bar code sticker is read and entered into the 
integration database; the mounting location on the string is chosen and the database is
queried for an appropriate module. The answer depends on the module type, on the inventory
of the available module at the integration centre and on the module depletion
voltage (see par.~\ref{sec:biasandvdepl}). \\
The chosen module is then prepared: it is optically inspected under a microscope and 
the two 1-D temporary bar code stickers, one from the module frame and the
other from the front-end hybrid kapton tail, are removed. Finally the module and ledges
contact surfaces are inspected and cleaned to allow for an optimal heath exchange with the 
cooling circuit. These preparation operations are often difficoult and, especially for 
the double sided modules, very delicate; for these reasons they amount for
a considarable fraction of the time spent to mount a module.\\
When a module is ready the operator mounts it on the structure by hand.
First the module is leaned onto the ledges keeping the microbonds away from the other
ledges or cooling pipes. 
%This operation, because of the presence of microbonds on the back 
%side and the more stringent mechanical tollerances,
%is quite difficult for double sided modules; for this reason a simple mechanical piece has
%been realized in order to guide the operators hand avoiding possible module damages.
When the module lies on the ledges the operator sligthly moves it to allow for the insertion
pin (Fig. \ref{fig:insets} c) glued on the frame on the front-end hybrid side, to
enters correctly the ledge precision socket. 
At this point the module has only the possibility to rotate around the pin axis.
This last degree of freedom is then fixed inserting a T-shaped aluminum
pin inside the frame U-shaped slot (Fig. \ref{fig:insets} b) and on the ledge precision socket. 
The U-shaped slot is used instead of a cylindrical hole, to allow for a module position 
matching also in presence of the unavoidable gluing errors on the precision insets and on the
ledge slot positions. 
The module is finally fixed to the ledges by four M1 type amagnetic steel screws. 
It should be noted again that the module position is not 
determined by the screws but only by the precision sockets and the insets and slots positions. \\

\begin{figure}[tbh]
\centering
\includegraphics[width=.7\textwidth]{Figs/collage.pdf}
\caption{TIB single-sided module insets:
\textbf{a:} The u-shaped slot glued on the carbon fiber module frame;
\textbf{b:} the T-pin inserted in the slot (seen from below);
\textbf{c:} front-end hybrid side precision insertion pin (seen from below).}
\label{fig:insets}
\end{figure}

The clearance between the module most delicate parts (bondings)
and the other structure present when the operation is performed (cooling pipes and ledges of the 
adjacent strings and modules already mounted) are, in case of single-sided modules, 
sufficiently large for a safe operation.
For the double-sided modules the cleareances are much reduced being 
of the order or less than a millimeter. 
In this case, to guide the module during its insertion, a simple mechanical
tool has been used. This tool simply 
adds temporary constraints (mechanical stops) to the structure avoiding possible accidental contacts 
between the module bondings and the rest of the shell.\\
When a module has been mounted on the structure its basic functionality is tested: 
only low voltages are
switched on and the I$^2$C communications with the various devices present on the hybrid, mother cable
and AOH are verified. Furthermore the module identity is checked and compared with the one stored on
the integration database using the DCU hardware ID as a fingerprint of each produced module. 
When a string of three modules has been mounted the I$^2$C communication are again verified and 
a noise run, at 400V bias, is taken. For the tests complete description see section \ref{sec:Tests}.

\subsubsection{TIB Control Ring Installation}
The TIB control electronics, which distributes clock, trigger and I$^2$C signals to the modules,
is located on a carbon fiber support mounted on the shell external surface
just above the modules. 
A thin aluminum foil has been glued on the support and electrically grounded 
to reduce possible interference between the logical control signals and
the module analog electronics. The DOHM and, when present, the AUX
are mounted on the support (Fig. \ref{fig:dohml4}), 
the preformed cables are connected to the Mother Cables.
The DOHM power cable is similar to the mother cable 'medusas' and it is directly plugger into
the DOHM. \\

\begin{figure}[tbh]
\centering
\includegraphics[width=.7\textwidth]{Figs/dohm.pdf}
\caption{A Layer 4 control ring circuitry. The DOHM and AUX boards are visible, the control ring
cables are connected to the mother cable heads (not visible).}
\label{fig:dohml4}
\end{figure}

The $4 \times 2$ optical fibers, which connect the two DOH to the FEC, should be very well protected
to assure a proper functionality of the control ring. In fact using the redundancy architecture
implemented for this circuitry it is possible to run the ring also in presence of a damaged
DOH, but the price to pay for a double failure in the DOH connections is of the order of 1-2\% of the
entire TIB.\\
 When the control ring is completed it is closed with another 
aluminun shielded carbon fiber cover (Fig. \ref{fig:dohml1})
and finally tested (see section \ref{sec:Tests}).\\ 

\begin{figure}[tbh]
\centering
\includegraphics[width=.7\textwidth]{Figs/L1DOHM.pdf}
\caption{A Layer 1 completed with its control rings. The DOHM and cable area is covered with
aa aluminum shielded carbon fiber plate.}
\label{fig:dohml1}
\end{figure}

Two PT1000 temperature probes per control ring are glued on the cooling manifolds. 
The probe wires are
routed through the DOHM via the Control Ring power cable up to the power supply racks where an 
interlock boards is located. 
The PT1000 resistance measurement is done using a 4-wire connection to avoid the
contribution coming from the 40 meters long power cable. One humidometer is located on the
DOHM board and it is also read out through dedicated wires on the Control ring power cable.

\subsection{TID Integration }
The integration of the TID rings has required the design of a handling tool that 
allows safe and easy manipulation of the mechanical structure, allows access and integration
on both side and provide support for the long optical fibers associated with the AOH and the DOH
of the DOHM. Moreover it should allow the assembly of rings into a full disk.

The handling tool is based on a aluminum crow plate with different mounting positions for: ring 
holding towers (4 to hold each ring) to adapt to any of the three different rings; U-shape
feets to allow the placing of the ring  front side upwards or downwards; stocking cylinder where to 
place and hold the long fibers; aligning jigs with pillar to allow to pair together two crowns
and join pairs of rings together to allow the assembly of ring into a disk. The handling tool will be called
 in the following as {\it integration crown} and it is shown in Fig.~\ref{fig:ringbench} for different configuration:
for a R1, R3 rings on the front side and a R1 for both sides.

The integration crown was made as light as possible, but rigid enough not to add mechanical stress to the 
ring or the disk, during the manipulation, specially during rotation  
of the structure (made manually using two handles) and the 
assembly of rings into a disk.  Weight????????

\begin{figure}[!htb]
\begin{center}
%  \includegraphics[width=0.49\textwidth]{Figs/R1-front.pdf}
%  \includegraphics[width=0.49\textwidth]{Figs/R2-front.pdf}
%  \includegraphics[width=0.49\textwidth]{Figs/R1-back.pdf}
%  \includegraphics[width=0.49\textwidth]{Figs/R3-front.pdf}

  \includegraphics[width=0.7\textwidth]{Figs/R1-front.pdf}
%  \includegraphics[width=0.49\textwidth]{Figs/R2-front.pdf}
  \includegraphics[width=0.7\textwidth]{Figs/R1-back.pdf}
%  \includegraphics[width=0.49\textwidth]{Figs/R3-front.pdf}
\end{center}
\caption{ The TID integration crown  holding R1 rings in front (top) and back (bottom) positions.}
\label{fig:ringbench}       % Give a unique label
\end{figure}
Once a new ring structure arrived, it was mounted on an integration crown. In order to identify easily the mother cable positions
during the integration bar code stickers were temporarelly glued to the ring. The integration work was made
 in parallel on several rings and disks at different steps of integration, therefore several integration crowns were used. 

TID cooling ledges for the AOH could arrived with a bending angle outside specification, due to manipulations 
of the ring and some touching that do not compromise the mechanical integrity of the cooling pipe. 
The clearance between parts in a disk is very small, in particular silicon sensors have a minimal distance of 2mm between 
AOH cooling ledges between ring 3 and ring 1, therefore mechanical checks were made and adjustment applied if needed.

\subsubsection{Services Installation }
The first step of integration was the installation of the services. For the TID a problem to be solved was the routing out of the optical fibers of the DOHs and  AOHs: all fibers have to exit from the TID at specific positions relative to  holes on Service Cylinder. 
To do that,  a set of AOHs associated to each mother cable was found,  all fibers were prepared to form a unique bundle that 
could be easily routed in the ring, holding together fibers using silicon rubber spirals. The same was done for pairs of DOHs going to the same DOHM.

All mother cables were prelimanarly tested in a dedicated test bench.  The ring integration begin installing all four
mother cables on each side of the ring: they were placed and screwed to the ring and equipped with 
CCU with the proper  $I^2C$ address. The connector of the mother cables reach the outermost radius of the ring to allow the connection to the power cables.  

Then the DOHM was fixed: for R2 and R3 the addition of a cable was needed in order to allow power connection at the outer radius of the ring. The ground of the DOHM was connected to a cable to reach the outer ring radius and will be used to make a unique grounding line for all TID+/-.  Then the DOHM  was equipped with a proper CCU and with the needed two DOHs:  their fiber were routed out properly and attached to integration crown via the stocking cylinder. 

 The control ring cables that connect DOHM to the mother cables were pre-formed in advance and were mounted and adapted into the ring. A 
complete functionality test of the control ring was then performed to verify that the  main control ring and the redundancy were working
fine. 

Two temperature sensors PT1000 were finally glued to the cooling manifold and  connected to the DOHM.


Details of the DOHM integration can be seen in the Fig.~ref{fig:tiddohms}.
\begin{figure}[!htb]
\begin{center}
  \includegraphics[width=0.4\textwidth,angle=90]{Figs/dohm-r1.pdf}
  \includegraphics[width=0.4\textwidth,angle=90]{Figs/dohm-r2.pdf}
  \includegraphics[width=0.4\textwidth,angle=90]{Figs/dohm-r3.pdf}
\end{center}
\caption{Integration of DOHM in the TID rings, from left to right R1, R2 and R3.}
\label{fig:tiddohms}       % Give a unique label
\end{figure}


Mounting of the AOH followed, screwing them temporarelly to the cooling ledge. The fiber lenght closes to the module was hold in place using foil of kapton properly shaped and glued to the ring. Then fiber bundle was routed up to the outmost ring radius at the position where the mother cables connectors are, and they are mechanical hold there by a kapton foil screwed to the ring: the remaining lenght was then fixed to the stocking cylinders. Some of these working solutions are in shown in Fig.~\ref{fig:tidfibers}. All

\begin{figure}[!htb]
\begin{center}
  \includegraphics[width=0.4\textwidth,angle=90]{Figs/Fiber-kapton1.pdf}
  \includegraphics[width=0.4\textwidth,angle=90]{Figs/Fiber-kapton3.pdf}
  \includegraphics[height=0.4\textwidth]{Figs/Fiber-kapton2.pdf} 
\end{center}
\caption{Few examples of solutions found for routing, bind together and fix the AOH fibers in the rings.}
\label{fig:tidfibers}       % Give a unique label
\end{figure}

\subsubsection{Module Mounting }
The mounting of TID modules follow exactly the same procedure explained in the TIB section~\ref{sect:tibmodules}.
Module mounting in rings is easier than in shells, since modules with following azimuthal angle are placed in opposite sides
of the ring. Neverthelss a lot of care was still needed: the precision pin was often very tight and the 
module cometa was placed on the U-shaped slot and hold down by the side precision insertion pin. Sistamatic
checks were made  on the electrical connection of the module ground with the carbon fiber. 

Once a full mother cable was ready, several test as exaplined later in the paper. To perform the noise test,
the entire ring was darken and measurements were done, first without bias and then with bias up to 100V to check 
good high voltage connection and that no evident physical damage was done to the silicon module. 


\subsubsection{Assembly of rings into a disk }

Integration crown equipped with alignment cylinder, also alignment ring pieces
put on place.  

Slow manual movement going down, rotating a pair of distance screws. 

Lot of care in last millimiter about fitting fixing holes between rings and about parallelism of rings
and critical point of very close parts. Then, unfix the top ring from the integration crown and
screwing down the rings.

Passing fibers from one integration crown to the other one. 

Detaching the integration crown

Disk assembly proceed for R1 on a R3, then R2 on R1-R3 structure.


\begin{figure}[!htb]
\begin{center}
  \includegraphics[height=0.6\textwidth]{Figs/Disk-assembly.pdf} 
\end{center}
\caption{Disk assembly.}
\label{fig:tidassembly}       % Give a unique label
\end{figure}


\begin{figure}[!htb]
\begin{center}
  \includegraphics[height=0.6\textwidth]{Figs/DISK.pdf} 
\end{center}
\caption{Disk assembled.}
\label{fig:tidassembly}       % Give a unique label
\end{figure}


\subsection{Integration Database}

Each active element, cables included, 
of the CMS experiment is identified by a bi-dimensional, radiation resistant,
bar code which is glued on the component itself redundantly coding a 14-digit number.
For the tracker the registered components are: 
detector modules, AOHs, DOHMs, DOHs, CCUs, Mother Cables,
optical fibres and ribbons, power and control cables. 
Using this code the object characteristics and the results of the tests previously performed
during the production phase, can be retrievied from 
the Tracker construction database~\cite{ref:database}.
Of equal, or even more, importance are the component
mounting locations and the connections between them.
This information is stored on the integration database at integration time.
Moreover the integration database acts also as an inventory to locate the components among
the various integration centers managing the shipping procedures.
It also contains a subset of the test data of all the 
devices and their functional status (good, broken, mounted, dismounted, etc...).\\
Along with module tests results also an important number is stored for each module:
the hardware identifier of the DCU chip
embedded with the module (or DcuHardId). This code can be retrieved during data acquisition, 
allowing for an unambiguous identification of a module.\\
A TIB/TID specific key was defined to store the location of mounted devices (named Geographical
Identifier, or GeoId): it is a string
composed of numerical fields separated by dots, as described in Table~\ref{tab:geoids}.
Bar code stickers with the GeoId are glued on the mechanical structure 
before the integration starts (Fig. \ref{fig:stickers}).

\begin{figure}[t]
\centering
\includegraphics[width=.6\textwidth]{Figs/stickers.pdf}
\caption{An empty shell with the bar code stickers identifying the strings.}
\label{fig:stickers}
\end{figure}

The first 7 numbers in a GeoId identify the string to which a device belongs, while the last
part of this code represents the physical location where the device is placed.

\begin{table}[h!]
\begin{center}
\begin{tabular}{l|ccc}
    & 1               & 2     & free value  \\
    \hline
  a & TIB             & TID              &             \\
  b & Forward ($z>0$) & Backward ($z<0$) &             \\
  c & Up ($y>0$)      & Down ($y<0$)     &             \\
  d &                 &                  & Layer \#    \\
  e & Inner           & Outer            &             \\
  f &                 &                  & Manifold \# \\
  g &                 &                  & String \#   \\
\end{tabular}
\caption[smallcaption]
{A generic $a.b.c.d.e.f.g$ GeoId identifies a string and  must be interpreted according
to this table. For example of GeoId 1.1.2.4.1.3.2 identifies the second string, of the
third manifold placed in the inner surface of the Layer 4 Down Forward TIB shell.}
\label{tab:geoids}
\end{center}
\end{table}

%The first number identifies TIB (1) against TID (2),
%the second number marks the forward part (1) vs. the backward (2). Hence TIB and TID codes become
%different. For TIB the third number identifies the upper/lower shell (1,2) and the fourth is
%the layer index (1-4).
%The following numbers represent if a device is placed on the inner or outer surface of a shell, 
%the cooling manifold a device belongs to and the string index insidethe same manifold.
Revision:	1.2
Committed:	Mon Jan 26 12:18:48 2009 UTC (16 years, 3 months ago) by lino
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Log Message:	Version TIB-TID draft0.1 26-01-2009