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\section{Integration Procedures} |
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\label{sec:Procedures} |
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TIB and TID have different integration procedure, each one being optimised |
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for the geometry and a logical sequence of installation and test of components. |
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|
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In this section the operations which are required to assemble a TIB shell and a TID |
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ring will be listed and described in details separatelly for the two subdetectors. |
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The various tests performed during the integration will just be mentioned among the |
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other steps in the sequence of operations: a deeper discussion will be done |
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in section \ref{sec:Tests}. |
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|
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For TIB and TID the integration process starts with the basic mechanical structure, |
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therefore respectivelly with a shell and a ring. This carbon fiber supporting structure has already |
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being equipped with cooling pipes and the precision mounting ledges |
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have been already glued; all parts have passed a quality assurance test with accurate measurements |
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of the precision parts and cooling test have been performed for the cooling circuits. |
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TIB and TID have different integration procedures, each one being optimised |
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for the geometry and the best installation and test logical sequence. |
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In this section the steps done to assembly a TIB shell and a TID |
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ring will be described also mentioning the tests performed in between and |
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described in detail in section~\ref{sec:Tests}. |
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|
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The integration process starts from the basic mechanical structure |
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already equipped with cooling pipes and the module support ledges |
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and fully qualified with respect to the precision mounting of the |
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mechanical parts and cooling performances. |
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|
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\subsection{TIB Integration Procedures} |
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To allow for a practical |
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and safe handling of the structure during the integration, the shell is mounted, via an aluminum |
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support frame which minimizes the mechanical stresses, |
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onto an integration bench. The bench allow to rotate the shell around the horizontally placed |
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cylindrical axis. |
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In this way all the internal and external strings can be |
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positioned in an optimal way for components mounting. The structure support frame holds also a |
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number of plastic boxes which are used to temporary store the analog optohybrids fibres and their |
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connectors allowing for their accessibility during the various tests. |
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To identify each string during the shell integration bar code stickers are temporary glued |
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on the structure. The string sticker is read and send to the integration database interface program |
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before each mounting operation.\\ |
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The shell is fixed, with the cylinder axis horizontal, onto an |
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integration bench using an aluminum frame to minimize the mechanical |
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stresses applied to the carbon fibre mechanical structure. |
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The bench allows the shell to be rotated around the cylinder |
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axis and is also know as ``roaster''. All the internal and external strings can be |
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positioned in an optimal way for access in a fast, practical and safe way. |
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|
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The shell supporting structure also holds a system consisting of plastic |
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trays to safely arrange the AOH fibres. To easily identify each string a bar code is temporarily stick on the |
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structure.\\ |
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%The string sticker is read and send to the integration database interface program |
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%before each mounting operation.\\ |
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A picture of a Layer 4 mechanical structure mounted on the integration bench is shown in Fig.~\ref{fig:bench}. |
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\begin{figure}[!htb] |
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\end{figure} |
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\subsubsection{TIB Control Ring Preparation} |
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Once the shell has been mounted on the integration bench the next operation is the preparation |
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of the Control Ring cables. |
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As described in section \ref{fig:ctrlring} the readout clock, |
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trigger and slow control signals are distributed to the |
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detector modules via a token ring structured system mounted on the shells. Each TIB layer is |
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served by different Control Rings whose dimensions, in terms of modules, depend on the layer position. |
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For example Layer one and two, which are equipped with |
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double sided modules, have control rings of 3 to 5 |
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strings, while Layer three and four have 13 to 15 single sided strings.\\ |
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The control ring boards (DOHM and AUX) are located on a carbon fiber plate mounted just above the modules on the |
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external part of the shell (see Fig. \ref{fig:dohm}). A carbon fiber cover of the same dimensions |
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of the plate close the control ring from above. An aluminum sheet has been glued |
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both on the plate and the cover to protect the module from possible electrical interference. When |
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monted this aluminum sheet is connected to the cooling manifold ground. |
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|
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\begin{figure}[!htb] |
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\begin{center} |
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\includegraphics[width=0.60\textwidth]{Figs/dohm.pdf} |
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\end{center} |
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\caption{A DOHM and an AUX (the smaller board) with control ring cables connected and mounted on a |
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layer 3 shell.} |
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\label{fig:dohm} % Give a unique label |
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\end{figure} |
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|
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As can be seen in Fig.~\ref{fig:dohm}, due to the variable number of strings connected and their |
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different positions with respect to the support |
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mechanics and cooling, each control cable have a different length and shape and |
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should be tailored in-situ to minimize the path satisfying all the mechanical constraints. |
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To avoid damages the control cable preparation should be done when the |
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modules are not yet installed on the |
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structure. The control cable preparation has to be done very carefully to |
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avoid mechanical interference with the services (cables, fibers and pipes) |
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that share the narrow space on the shell flange |
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(20mm in the z direction and 6mm in the radial one).????????????????????????????? |
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When the control ring has been cabled it is dismounted from the structure |
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to proceed with AOH and module installation. \\ |
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For layer three and four the part of the control cables |
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which is not protected by the carbon fiber plate |
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is shielded using a thin Aluminum foil. |
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\subsubsection{Analog Opto Hybrid Installation on Shells} |
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\subsubsection{AOH Installation} |
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The small AOH board ($3\times 2.2 cm^2$) |
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is simply screwed to a C-shaped ledge which is directly glued on the string cooling |
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pipes. Due to mechanical constraints the |
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fibers, and their connectors, should be carefully routed to the outside of the shell through a |
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is screwed to a C-shaped ledge which is directly glued on the string cooling |
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pipes. Due to mechanical constraints, the |
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fibers and their connectors should be carefully routed to the outside of the shell through a |
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number of ledges, holes and pipes keeping |
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them as close as possible to the carbon fiber structure surface to which they are finally fixed |
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using kapton strips. The part of the pig-tail fibers which is not housed on the shell |
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is temporary stored in the plastic |
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boxes fixed to the shell support frame. Their connectors are inserted into |
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optical plugs which |
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ease the many connect-disconnect operations to be done during the tests.\\ |
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Since the optical fibers are quite fragile they have been |
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protected when they cross the most critical points. |
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For example at the |
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shell flange, where the fibers should turn at 90$^\circ$ together with |
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all the other services, |
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they are grouped together and covered by a thin silicon rubber spiral (see Fig. \ref{fig:spiraline}). |
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This procedure resulted in very reliable protection since only 4 fibres out of |
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6984 was found broken at the end of TIB integration. |
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using glued kapton strips. The main part of the pig-tail fibers |
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remains out of the shell and is temporary stored in the plastic |
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trays. The optical connectors are inserted |
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into arrays of dummy optical plugs fixed at the far-end of the |
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structure to be always accessible during the various tests which |
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require many connect-disconnect operations.\\ |
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|
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Since the optical fibers are quite fragile, special protections have |
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been arranged in the most critical points. |
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For example at the shell flange the fibers have to be bent by $90^\circ$ and |
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routed together with other services towards the service cylinder. |
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In this particular region the fibres are grouped together and |
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covered by a silicon rubber spiral (see |
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Fig.~\ref{fig:spiraline}). |
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|
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The procedure resulted to be very effective: only few fibres out of |
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a total of 9192 were found broken at the end of TIB/TID integration. |
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|
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A layer 2 shell with AOH mounted on is shown in Fig.~\ref{fig:aoh}. |
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\begin{figure}[!htb] |
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\begin{center} |
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\includegraphics[width=0.60\textwidth]{Figs/aoh.pdf} |
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\label{fig:spiraline} % Give a unique label |
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\end{figure} |
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|
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Since the AOH are powered by the module kapton tail they cannot be easily tested before the |
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modules are installed. This was a source of concerns when the integration has started: the |
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operation of changing a broken AOH when the modules are already installed requires dismounting |
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the entire string with the result of a considerable increase of the risk of damage to the |
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mounted objects. The number of AOH that should be replaced was anyway very small at the level |
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of one per shell. |
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|
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\subsubsection{Shell mother Cable Installation} |
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The Mother Cables are inserted into the structure when the AOH have been mounted and the optical |
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fibers fixed to the shell and protected. This procedure is in some cases complicated by mechanical |
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constraints at the level of the shell front flange, where the mother cables are entered in the shell, |
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and cooling manifolds. When the Mother Cables are inserted they |
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are connected to the power cables (medusa cables) which are temporary fixed to the shell supporting |
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frame. \\ |
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The 'medusa cables' are multi-strand cables with each conductor separatly insulated. |
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This cable characteristic helps in efficiently use the very limited available space on the TIB |
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front flange allowing to 'distribute' the cable among the other services. \\ |
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To make the control ring redundancy properly working each mother cable has to be provided with a |
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CCU whose address is in a fixed order with respect to its position in the token ring. This |
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position depends on how the control ring has been cabled, so this information |
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has to be taken in mind when the Mother Cables are inserted into the structure.\\ |
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Since the AOH is powered by the module kapton tail its test without |
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the corresponding module is not straightforward requiring a temporary |
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connector inserted into the fragile AOH plug. For this reason it has been choosen |
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not to test AOHs immediatly after their installation, despite the |
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operation of changing a broken AOH when the modules are already |
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installed is very difficult and somehow risky for the nearby objects |
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already mounted. Eventually, the number of AOH that had to be replaced |
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was anyway very small, at the level of one per shell/disk. |
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|
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\subsubsection{Mother Cable Installation} |
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The Mother Cables were put in place after the AOH |
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mounting and when all optical fibers have been fixed to the shell and |
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adequately protected. The mother cables are inserted below |
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the ledges by sliding them on |
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the shell surface from the flange. The ledges support keep the |
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mother cable in place (see~\ref{fig:l3detail}). This procedure is in some cases |
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complicated by mechanical |
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constraints at the level of the shell front flange |
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and cooling manifolds. After the Mother Cables have been inserted they |
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are connected to the power cables (medusa cables) which are temporary |
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fixed to the shell supporting frame. \\ |
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The {\em medusa cable} is a bundle of single insulated copper wires with |
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no definited envelope and geometry. This helps in efficiently |
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use the very limited available space on the TIB front flange during the |
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seervice routing.\\ |
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% allowing |
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%to 'distribute' the cable among the other services. \\ |
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To ease the implementation of the control ring redundancy, CCUs are |
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put in the ring with a pre-defined hardware address order. So, for each |
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string position in the ring, care must be taken to choose the proper mother cable, |
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that comes with the correct address CCUM already on it. |
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%, has to be provided with a |
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%CCU whose address is in a fixed order with respect to its position in |
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%the token ring. |
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\begin{figure}[!htb] |
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\begin{center} |
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\includegraphics[width=0.60\textwidth]{Figs/mc_detail_full.png} |
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\end{center} |
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\caption{A symplified detail of the $r\phi$ section of TIB L3 |
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mechanical drawing.} |
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\label{fig:l3detail} % Give a unique label |
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\end{figure} |
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|
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\subsubsection{Module Mounting}\label{sect:tibmodules} |
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Both single and double sided modules are mounted on the shell by hand. |
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They are fixed on two precision ledges: one supports the module below the front-end |
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hybrid and the other below the carbon fiber frame at the opposite end. |
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The ledges precisely define the module position and also, being in contact with the cooling pipes, |
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act as heath sink for the front-end hybrid and sensor generated power. |
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The shape of the ledges is different for the single sided and for the two kind |
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of double-sided modules, |
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reflecting, in this latter case, the two different orientations of the "stereo" side of the module. |
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Each ledge has two threaded holes (M1 screw type); one of them is concentric with a |
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2 mm diameter socket |
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acting as a slot for the module precision aluminum inset which fixes the detector |
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position. The socket has been precisely drilled with respect to the ledge edges which |
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in turns are the reference position for the precision mask used to glue them on the "shell". |
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All kind of modules have an aluminum pin glued on the carbon fiber frame at the hybrid end |
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and an aluminum U-shaped slot glued at the module opposite end. This two module insets, |
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together with the two ledge sockets and a pin to be inserted into the U-shaped slots, |
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define the module position with respect to the shell.\\ |
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Before mounting a module on the shell the structure is rotated to horizontally place |
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the corresponding string. Then the string bar code sticker is read and entered into the |
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integration database; the mounting location on the string is chosen and the database is |
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queried for an appropriate module. The answer depends on the module type, on the inventory |
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of the available module at the integration centre and on the module depletion |
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Both single modules and double sided module assemblies are mounted on the shell by hand. |
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The module is supported below the front-end |
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hybrid and on the opposite side by two ledges support that precisely |
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define the module position and act as heat sink |
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%for the front-end hybrid and the sensor generated power |
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being in contact with the cooling pipes. |
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The shape of the ledges is different for the single sided modules and |
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for the double-sided module assemblies. In the latter case the |
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``stereo'' module sits on the structure upside-down and the ledge |
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below the hybrid has a milled slot to ensure enough room to the |
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front-end hybrid. The ledge on the opposite side has two different |
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shapes reflecting the two orientations of the ``stereo'' modules. |
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Each ledge has two M1 threaded holes. One is concentric with a 2mm |
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diameter socket. |
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The module features one precision pin on both short sides that fits |
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into the socket (Fig. \ref{fig:insets} c). The milling of the socket and the glueing of the |
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ledge onto the shell is done by using the same reference, i.e. the |
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ledge edges, so to ensure an accurate positioning. |
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The module pin at the hybrid side is glued onto the module frame. The |
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one at the opposite side, however, fits into an 'U'-shaped |
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slot a design that allows for movements along the module long side. In |
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a device that will be affected to huge temperature changes, this is an |
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essential feature to compensate for thermal variations while ensuring |
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mechanical precision. |
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|
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Before mounting a module on the shell the structure is rotated to place |
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the corresponding string in a confortable and horizontal |
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position. Then the module inventory database is queried for an |
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appropriate module. The answer depends on module type and availability |
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at the integration centre and on the module depletion |
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voltage (see par.~\ref{sec:biasandvdepl}). \\ |
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The chosen module is then prepared: it is optically inspected under a microscope and |
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the two 1-D temporary bar code stickers, one from the module frame and the |
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other from the front-end hybrid kapton tail, are removed. Finally the module and ledges |
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contact surfaces are inspected and cleaned to allow for an optimal heath exchange with the |
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cooling circuit. These preparation operations are often difficoult and, especially for |
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the double sided modules, very delicate; for these reasons they amount for |
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a considarable fraction of the time spent to mount a module.\\ |
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When a module is ready the operator mounts it on the structure by hand. |
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First the module is leaned onto the ledges keeping the microbonds away from the other |
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ledges or cooling pipes. |
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%This operation, because of the presence of microbonds on the back |
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%side and the more stringent mechanical tollerances, |
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%is quite difficult for double sided modules; for this reason a simple mechanical piece has |
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%been realized in order to guide the operators hand avoiding possible module damages. |
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When the module lies on the ledges the operator sligthly moves it to allow for the insertion |
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pin (Fig. \ref{fig:insets} c) glued on the frame on the front-end hybrid side, to |
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enters correctly the ledge precision socket. |
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At this point the module has only the possibility to rotate around the pin axis. |
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This last degree of freedom is then fixed inserting a T-shaped aluminum |
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pin inside the frame U-shaped slot (Fig. \ref{fig:insets} b) and on the ledge precision socket. |
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The U-shaped slot is used instead of a cylindrical hole, to allow for a module position |
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matching also in presence of the unavoidable gluing errors on the precision insets and on the |
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ledge slot positions. |
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The module is finally fixed to the ledges by four M1 type amagnetic steel screws. |
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It should be noted again that the module position is not |
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determined by the screws but only by the precision sockets and the insets and slots positions. \\ |
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|
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The module identified for mounting then undergoes an optical |
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inspection to check for obvious damages and the temporary labels used |
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during the production are removed. Finally the module and ledges |
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contact surfaces are inspected and cleaned to ensure an optimal heat |
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exchange with the cooling circuit. The operations that imply the |
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handling of the modules are very delicate and account for |
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a considarable fraction of the time spent into module mounting.\\ |
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|
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The single sided module or the double side modules assembly is mounted |
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on the structure by hand. It is first leaned onto the ledges and then is |
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gently slit until the pin at the hybrid side enters into the precision |
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socket. Now can only the rotation around the pin axis is possible. |
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The mounting is completed by inserting in the corresponding precision |
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socket the T-shaped aluminum pin placed in the U-shaped slot |
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(Fig. \ref{fig:insets} b) located on the frame short side opposite to |
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the hybrid. The module is finally tighetned by the four M1 screws by |
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using a limited-torque screw driver. |
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|
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\begin{figure}[tbh] |
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\centering |
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\includegraphics[width=.7\textwidth]{Figs/collage.pdf} |
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\caption{TIB single-sided module insets: |
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\textbf{a:} The u-shaped slot glued on the carbon fiber module frame; |
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\textbf{b:} the T-pin inserted in the slot (seen from below); |
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\textbf{a:} The U-shaped slot glued on the carbon fiber module frame; |
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\textbf{b:} the T-shaped pin inserted in the slot (seen from below); |
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\textbf{c:} front-end hybrid side precision insertion pin (seen from below).} |
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\label{fig:insets} |
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\end{figure} |
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|
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The clearance between the module most delicate parts (bondings) |
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and the other structure present when the operation is performed (cooling pipes and ledges of the |
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The clearance between the module most fragile parts (bondings) |
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and the other surrounding structures when the operation is performed (cooling pipes and ledges of the |
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adjacent strings and modules already mounted) are, in case of single-sided modules, |
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sufficiently large for a safe operation. |
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For the double-sided modules the cleareances are much reduced being |
| 196 |
< |
of the order or less than a millimeter. |
| 197 |
< |
In this case, to guide the module during its insertion, a simple mechanical |
| 198 |
< |
tool has been used. This tool simply |
| 199 |
< |
adds temporary constraints (mechanical stops) to the structure avoiding possible accidental contacts |
| 200 |
< |
between the module bondings and the rest of the shell.\\ |
| 201 |
< |
When a module has been mounted on the structure its basic functionality is tested: |
| 202 |
< |
only low voltages are |
| 203 |
< |
switched on and the I$^2$C communications with the various devices present on the hybrid, mother cable |
| 204 |
< |
and AOH are verified. Furthermore the module identity is checked and compared with the one stored on |
| 205 |
< |
the integration database using the DCU hardware ID as a fingerprint of each produced module. |
| 206 |
< |
When a string of three modules has been mounted the I$^2$C communication are again verified and |
| 207 |
< |
a noise run, at 400V bias, is taken. For the tests complete description see section \ref{sec:Tests}. |
| 208 |
< |
|
| 209 |
< |
\subsubsection{TIB Control Ring Installation} |
| 210 |
< |
The TIB control electronics, which distributes clock, trigger and I$^2$C signals to the modules, |
| 211 |
< |
is located on a carbon fiber support mounted on the shell external surface |
| 212 |
< |
just above the modules. |
| 213 |
< |
A thin aluminum foil has been glued on the support and electrically grounded |
| 194 |
> |
sufficiently large for a safe operation. For the double-sided module |
| 195 |
> |
assemblies the cleareances are much reduced, of the order or less than a millimeter. |
| 196 |
> |
In this case, to ease the mounting, a simple mechanical guidance |
| 197 |
> |
template has been designed to further reduce the risk of possible |
| 198 |
> |
accidental damage of the microbonds or the sensor. |
| 199 |
> |
|
| 200 |
> |
Once a module or a double sided assembly is mounted its basic |
| 201 |
> |
functionality is tested by feeding low voltages and checking I$^2$C |
| 202 |
> |
communications with the various devices present on the hybrid, the CCU |
| 203 |
> |
on the mother cable and the AOH. This also allows the module identity |
| 204 |
> |
to be certified by using the DCU hardware ID. |
| 205 |
> |
Once a string of three or six modules is completed the I$^2$C |
| 206 |
> |
communications are checked again and a pedestal and noise run is taken |
| 207 |
> |
with a HV bias at 400V. For the tests complete description see |
| 208 |
> |
section~\ref{sec:Tests}. |
| 209 |
> |
|
| 210 |
> |
\subsubsection{Control Ring Installation} |
| 211 |
> |
The control electronics that supervises the control ring, i.e. the |
| 212 |
> |
DOHM boards and in case the AUXs, are located on a carbon fiber skin |
| 213 |
> |
are mounted on the shell external surface just above the modules by carbon fiber pillars and aluminum supports (Fig. \ref{fig:dohm}). |
| 214 |
> |
A thin aluminum foil has been glued on the skin and electrically grounded |
| 215 |
|
to reduce possible interference between the logical control signals and |
| 216 |
< |
the module analog electronics. The DOHM and, when present, the AUX |
| 217 |
< |
are mounted on the support (Fig. \ref{fig:dohml4}), |
| 218 |
< |
the preformed cables are connected to the Mother Cables. |
| 219 |
< |
The DOHM power cable is similar to the mother cable 'medusas' and it is directly plugger into |
| 220 |
< |
the DOHM. \\ |
| 221 |
< |
|
| 222 |
< |
\begin{figure}[tbh] |
| 223 |
< |
\centering |
| 224 |
< |
\includegraphics[width=.7\textwidth]{Figs/dohm.pdf} |
| 225 |
< |
\caption{A Layer 4 control ring circuitry. The DOHM and AUX boards are visible, the control ring |
| 226 |
< |
cables are connected to the mother cable heads (not visible).} |
| 227 |
< |
\label{fig:dohml4} |
| 216 |
> |
the module analog electronics. All mother cables are then connected to |
| 217 |
> |
the DOHM (and AUX) ports by using a set of appropriately terminated |
| 218 |
> |
flat-cables that have been preprared before, on the empty structure, |
| 219 |
> |
by using dummy replicas of the DOHS/AUX boards and mother cables. |
| 220 |
> |
|
| 221 |
> |
Each shell needs of three to six Control Rings, generally |
| 222 |
> |
differing also withinh the same shell with respect to the number of |
| 223 |
> |
served strings and the geographical distribution of these strings |
| 224 |
> |
into the shell. |
| 225 |
> |
For example, Layer 1 and 2, which are equipped with |
| 226 |
> |
double sided modules, have control rings of 3 to 5 |
| 227 |
> |
strings, while Layer three and four have 13 to 15 single sided strings.\\ |
| 228 |
> |
\begin{figure}[!htb] |
| 229 |
> |
\begin{center} |
| 230 |
> |
\includegraphics[width=0.60\textwidth]{Figs/dohm.pdf} |
| 231 |
> |
\end{center} |
| 232 |
> |
\caption{A Layer 3 control ring circuitry during the cable preparation |
| 233 |
> |
witha DOHM and an AUX (the smaller board) with control ring cables |
| 234 |
> |
connected the mother cable heads (not visible).} |
| 235 |
> |
\label{fig:dohm} % Give a unique label |
| 236 |
|
\end{figure} |
| 237 |
|
|
| 238 |
< |
The $4 \times 2$ optical fibers, which connect the two DOH to the FEC, should be very well protected |
| 239 |
< |
to assure a proper functionality of the control ring. In fact using the redundancy architecture |
| 240 |
< |
implemented for this circuitry it is possible to run the ring also in presence of a damaged |
| 241 |
< |
DOH, but the price to pay for a double failure in the DOH connections is of the order of 1-2\% of the |
| 242 |
< |
entire TIB.\\ |
| 243 |
< |
When the control ring is completed it is closed with another |
| 244 |
< |
aluminun shielded carbon fiber cover (Fig. \ref{fig:dohml1}) |
| 245 |
< |
and finally tested (see section \ref{sec:Tests}).\\ |
| 238 |
> |
As can be seen in Fig.~\ref{fig:dohm}, due to the variable number of strings connected and their |
| 239 |
> |
different positions with respect to the support |
| 240 |
> |
mechanics and cooling, each control cable have a different length and shape and |
| 241 |
> |
should be tailored in-situ to minimize the path satisfying all the mechanical constraints. |
| 242 |
> |
Each control cable path has been optimized as a consequence of the |
| 243 |
> |
very limited room available for services. |
| 244 |
> |
For layer three and four the part of the control cables |
| 245 |
> |
which is not protected by the carbon fiber plate |
| 246 |
> |
is shielded using a thin Aluminum foil.\\ |
| 247 |
> |
The $4 \times 2$ optical fibers, which connect the two DOH to the FEC, |
| 248 |
> |
are cerefully routed and protected at the flange. In fact the |
| 249 |
> |
redundancy architecture allows the ring to work also if the connection |
| 250 |
> |
to the master DOH fails, but the price to pay if both DOH connections |
| 251 |
> |
fail is of the order of 1-2\% of the entire TIB.\\ |
| 252 |
> |
The DOHM cabling is completed by the power cable, very similar to the |
| 253 |
> |
mother cable 'medusas', and by the wiring of two PT1000 temperature |
| 254 |
> |
probes per control ring that comes already glued on the cooling manifolds. |
| 255 |
> |
The four probe wires are in fact routed through the DOHM via the Control |
| 256 |
> |
Ring power cable up to the power supply racks where the interlock |
| 257 |
> |
boards are also located. The four-wire resistance measurement |
| 258 |
> |
of the PT1000 is necessary to avoid the contribution of the |
| 259 |
> |
40 meter long power cable. |
| 260 |
> |
Also a humidity meter is hosted on the DOHM board; it is read out |
| 261 |
> |
through dedicated wires on the Control Ring power cable. |
| 262 |
> |
|
| 263 |
> |
A thinner carbon fiber skin is used as a protecting cover. Electrical |
| 264 |
> |
shielding is ensured by an aluminum foil glued to the cover and |
| 265 |
> |
grounded (Fig. \ref{fig:dohml1}). Finally the control ring is tested (see section \ref{sec:Tests}).\\ . |
| 266 |
|
|
| 267 |
|
\begin{figure}[tbh] |
| 268 |
|
\centering |
| 272 |
|
\label{fig:dohml1} |
| 273 |
|
\end{figure} |
| 274 |
|
|
| 262 |
– |
Two PT1000 temperature probes per control ring are glued on the cooling manifolds. |
| 263 |
– |
The probe wires are |
| 264 |
– |
routed through the DOHM via the Control Ring power cable up to the power supply racks where an |
| 265 |
– |
interlock boards is located. |
| 266 |
– |
The PT1000 resistance measurement is done using a 4-wire connection to avoid the |
| 267 |
– |
contribution coming from the 40 meters long power cable. One humidometer is located on the |
| 268 |
– |
DOHM board and it is also read out through dedicated wires on the Control ring power cable. |
| 275 |
|
|
| 276 |
|
\subsection{TID Integration } |
| 277 |
|
The integration of the TID rings has required the design of a handling tool that |
