| 3 |
|
|
| 4 |
|
\subsection{The Silicon Module} |
| 5 |
|
|
| 6 |
< |
The TIB and TID module\ref{table:modules} consist of a carbon fiber support |
| 6 |
> |
The TIB and TID modules (table~\ref{table:modules}) |
| 7 |
> |
consist of a carbon fiber support |
| 8 |
|
frame that holds a single silicon |
| 9 |
|
sensor~\cite{ref:mask}\cite{ref:sensors} and the front-end electronics |
| 10 |
< |
hybrid circuit\cite{ref:hybrid}. |
| 10 |
> |
hybrid circuit~\cite{ref:hybrid}. |
| 11 |
|
These detectors are produced from individual, 320~$\mu$m thick, sensors. |
| 12 |
|
All silicon strip sensors are of the |
| 13 |
|
single-sided ``p-on-n'' type |
| 14 |
|
with integrated decoupling capacitors, aluminium readout strips |
| 15 |
|
and polysilicon bias resistors. |
| 16 |
|
The sensor is aligned with respect to the same frame |
| 17 |
< |
aluminum insets that are used to fix the module the ledges in such a |
| 17 |
> |
aluminum inserts that are used to fix the module the ledges in such a |
| 18 |
|
way the sensor positioning is guaranteed with respect to the support |
| 19 |
|
structure~\cite{ref:assembly}.\\ |
| 20 |
|
Double-sided detectors are built by simply assembling two independent |
| 21 |
|
single-sided modules (``R-Phi'' and ``Stereo'') back to back. |
| 22 |
|
The double-sided TIB layers and TID rings are equipped with module |
| 23 |
|
sandwiches capable of a space point measurement and obtained by |
| 24 |
< |
coupling back-to-back a $r\phi$ module and a special ``stereo'' |
| 25 |
< |
module with the sensor tilted by $100\mrad$. |
| 24 |
> |
coupling back-to-back a ``R-Phi'' module and a special ``Stereo'' |
| 25 |
> |
module with the sensor tilted by $100\mrad$ with respect to the other. |
| 26 |
|
The stereo sensor and electronics are identical to the R-Phi ones, the only |
| 27 |
|
difference being in the support mechanics and pitch adapters. \\ |
| 28 |
|
|
| 80 |
|
\hskip 5mm |
| 81 |
|
\includegraphics[height=0.3\textwidth, width=0.45\textwidth]{Figs/moduleds.pdf} |
| 82 |
|
\end{center} |
| 83 |
< |
\caption{A ring 3 TID module (left panel). A TIB double-sided module, |
| 83 |
> |
\caption{A ring 3 TID module (left panel). A TIB double-sided assembly, |
| 84 |
|
the ``stereo'' module is visible reflected by a mirror (rigth panel).} |
| 85 |
|
\label{fig:moduleds} % Give a unique label |
| 86 |
|
\label{fig:moduletid} |
| 90 |
|
The multilayer kapton hybrid circuit holds the module front-end |
| 91 |
|
electronics consisting of four main components: the readout chips |
| 92 |
|
(APV25) and three ASICs (the Multiplexer, the PLL and the DCU). All |
| 93 |
< |
devices are addressed and controlled by a I$^2$C serial bus.\\ |
| 93 |
> |
devices are addressed and controlled by a I$^2$C serial bus~\cite{ref:i2c}.\\ |
| 94 |
|
The signals coming from each strip are processed by four or six front-end |
| 95 |
|
readout chips, connected to the silicon sensor strips by means of a glass |
| 96 |
|
substrate pitch-adapter. The APV25~\cite{ref:apv} |
| 116 |
|
pipeline address and the chip error status; two APV25 are multiplexed |
| 117 |
|
on a differential line by the Multiplexer chip~\cite{ref:mux}. |
| 118 |
|
In absence of data to stream out, for synchronization purposes, the |
| 119 |
< |
APV issues a 25ns pulse called ``tick mark'' |
| 119 |
> |
APV25 issues a 25ns pulse called ``tick mark'' |
| 120 |
|
with a period of 70 clock cycles.\\ |
| 121 |
< |
The PLL chip\cite{ref:pll} allows the clock to be delayed by 1.04ns |
| 121 |
> |
The Phase Locked Loop (PLL) chip~\cite{ref:pll} allows the clock to be delayed by 1.04ns |
| 122 |
|
steps, to |
| 123 |
|
compensate for path differences of control signals and for any |
| 124 |
|
electronics delay. The PLL also decodes the trigger signals that are |
| 125 |
|
encoded on the clock line.\\ |
| 126 |
< |
The Detector Control Unit (DCU) contains an eight-channel ADC, |
| 126 |
> |
The Detector Control Unit (DCU)~\cite{ref:dcu} contains an eight-channel ADC, |
| 127 |
|
two constant current sources and a temperature sensor. It |
| 128 |
|
monitors two sets of thermistors, one on the sensor |
| 129 |
|
and one on the hybrid, its own internal temperature, the |
| 138 |
|
The Analog-Opto Hybrids~\cite{ref:aoh} (AOH) performs the |
| 139 |
|
electrical-to-optical conversion of the electrical signals of the two |
| 140 |
|
or three APV25 pairs, depending on the module type, by means of |
| 141 |
< |
radiation hard lasers~\cite{Gill:2005ui}. There is one AOH |
| 141 |
> |
radiation tolerant lasers and components\cite{ref:laserdriver}. |
| 142 |
> |
There is one AOH |
| 143 |
|
per module, sitting on a ledge glued on the cooling pipe very close to |
| 144 |
|
the front-end hybrid. Multi-mode optical fibers~\cite{ref:opto} |
| 145 |
< |
transport the signal to the counting room where the FEDs~\cite{ref:fed} |
| 145 |
> |
transport the signal to the counting room where the |
| 146 |
> |
Front End Drivers (FEDs)~\cite{ref:fed} |
| 147 |
|
convert back the signal to an electrical one and digitize it. |
| 148 |
|
Each AOH has two or three two meter long pig-tail |
| 149 |
|
optical fibres ending with an optical plug.\\ |
| 165 |
|
\label{fig:ctrlring} |
| 166 |
|
|
| 167 |
|
The control of the modules front-end electronic is implemented by means of a |
| 168 |
< |
hierarchical structure organized in groups of modules~\cite{ref:dohm}. Each group is |
| 169 |
< |
controlled by a Communication and Control Unit (CCU) taht represents a |
| 168 |
> |
hierarchical structure organized in groups of modules~\cite{ref:dohm}. |
| 169 |
> |
Each group is |
| 170 |
> |
controlled by a Communication and Control Unit (CCU)~\cite{ref:ccu} |
| 171 |
> |
that represents a |
| 172 |
|
``node'' in a ``token-ring'' formed by several daisy-chained CCUs and |
| 173 |
|
known as {\it control ring}. The control ring is mastered by a Front End |
| 174 |
|
Controller, FEC~\cite{ref:opto}, located outside the experiment by |
| 176 |
|
Control Rings. |
| 177 |
|
|
| 178 |
|
\begin{description} |
| 179 |
< |
\item[Digital Opto Hybrid Module] The FEC optical signals are converted into electrical signals by two DOHs |
| 180 |
< |
(Digital Opto-Hybrid) that send clock, trigger, and control signals to |
| 179 |
> |
\item[Digital Opto Hybrid Module] The FEC optical signals are converted into electrical signals |
| 180 |
> |
by two |
| 181 |
> |
Digital Opto-Hybrids (DOHs)~\cite{ref:doh} that send clock, trigger, and control signals to |
| 182 |
|
the token ring of CCUs. The DOHs are physically located on a board, |
| 183 |
< |
Digital Opto Hybrid Module~\cite{ref:dohm} (DOHM), that provides up to |
| 183 |
> |
Digital Opto Hybrid Module (DOHM)~\cite{ref:dohm}, that provides up to |
| 184 |
|
15 ports (7 on the main DOHM board plus 8 on its |
| 185 |
|
secondary extension or AUX) to implement the token ring. Each port |
| 186 |
|
connects the DOHM to a CCU located on the Mother Cable head |
