From f3d92ab2dbf4beaa32bbccc6996f93b8140be3d1 Mon Sep 17 00:00:00 2001 From: tischler Date: Tue, 4 Feb 2014 12:18:11 +0100 Subject: [PATCH] First draft --- .../Layout_of_the_MVD.tex | 71 +++++++++++++++++++ 1 file changed, 71 insertions(+) create mode 100644 GSI_2014_TT_Layout_of_the_MVD/Layout_of_the_MVD.tex diff --git a/GSI_2014_TT_Layout_of_the_MVD/Layout_of_the_MVD.tex b/GSI_2014_TT_Layout_of_the_MVD/Layout_of_the_MVD.tex new file mode 100644 index 0000000..2c63540 --- /dev/null +++ b/GSI_2014_TT_Layout_of_the_MVD/Layout_of_the_MVD.tex @@ -0,0 +1,71 @@ +\documentclass{JACoW-GSI-2013} +\usepackage{graphicx} +\usepackage{url} +\usepackage[utf8]{inputenc} +\usepackage{amsmath} +\usepackage{amssymb} +%% GSI Scientific Report 2013 +%% \setlength{\titleblockheight}{27mm} KG +\setlength{\titleblockheight}{35mm} + +\begin{document} +\title{Layout of the Micro Vertex Detector for the CBM experiment\thanks{Work supported by BMBF (05P12RFFC7), \hbox{HIC for FAIR}, EU-FP7 HadronPhysics3, GSI and H\hbox{-}QM Helmholtz Research School.}} + +\author[]{T. Tischler} +\author[]{S. Amar-Youcef} +\author[]{M. Deveaux} +\author[]{M. Koziel} +\author[]{C. M{\"u}ntz} +\author[]{J. Stroth for the CBM-MVD Collaboration} +\affil[]{Institut f{\"u}r Kernphysik, Goethe-Universit{\"a}t, Frankfurt} + +\maketitle + +The Micro Vertex Detector (MVD) of the CBM experiment will be equipped with CMOS Monolithic Active Pixel Sensors developed at the IPHC, Strasbourg. This sensor technology will meet the constraints formulated by the physics cases the MVD will contribute to the measuremnents regarding radiation hardness, spatial resolution and read-out speed best at the time given. Recently developed sensor prototypes, \cite{1}, providing the sensor architecture to be used for the sensors to be integrated into the MVD allowed to revise the sensor arrangement within the acceptance of the MVD.\\ + +The MVD will consist of up to four detector stations to be positioned at $50 /100 /150 /200$ mm downstream the target. The construction of the fourth MVD station is currently under discussion. The assumed sensor dimensions of $30 \cdot 13$ mm$^{2}$ feature an in-active area of $3 \cdot 10$ mm$^{2}$ for the on-chip read-out electronics. This in-active area requires a double-sided positioning of the sensors on the MVD stations to achieve the optimum acceptance coverage. The thickness of the sensors will be $50\; \mu$m which requires dedicated customized sensor positioning tools.\\ + +\begin{table}[!htbp] + \centering + \begin{tabular}{@{}lllc@{}} + \multicolumn{2}{c}{Station} & Number of & Carrier \\ + number & position [mm] & sensors & type \\ + \hline + $0$ & $50$ & $8$ & CVD \\ + $1$ & $100$ & $40$ & CVD \\ + $2$ & $150$ & $84$ & CF-TPG-CF \\ + $3$ & $200$ & $160$ & CF-TPG-CF \\ + \hline + Total & & $296$ & \\ + \end{tabular} + \caption{The number of sensors required per MVD station.} + \label{tab:sensornumber} +\end{table} + +The operation of the MVD in the vacuum to minimize multiple scattering of the produced particles results in the mandatory cooling of the sensors. At the same time, the material budget of the MVD stations has to be limited due to its significant impact on the tracking and reconstruction efficiency. High performance carbon-based materials - offering the best combination of an excellent heat conductivity and a low contribution to the material budget of the MVD station - will be used as cooling support in the detector acceptance. For the stations positioned at $50$ mm and $100$ mm, $150\; \mu$m thin CVD diamond (CVD) carriers will be used as cooling support, while for the third and possible fourth MVD station carbon fibre-encapsulated Thermal Pyrolithic Grafite (TPG) is foreseen. The thickness of the carbon fibre-encapsulated TPG is $500\; \mu$m including two $60\; \mu$m carbon fibre plans. Outside of the active area, the constraints due to minimizing the material budget and the resulting multiple scattering are less stringent which allows to position actively cooled aluminum heat sinks. These are held by dedicated half station support structures levelling the different heat sink dimension of the stations, as shown in figure \ref{fig:overview}. The MVD half stations are positonend on base plates to allow the movement of the MVD apart the beam line while beam tuning and beam focusing. + + +\begin{figure}[htb] +\centering +\includegraphics*[width=75mm]{MVD_overview.pdf} +\caption{The overview of the MVD is depicted. For one of the two MVD half station groups is set to transparent to ease the visualization. The beam is coming from the right.} +\label{fig:overview} +\end{figure} + +The material budget limit for the first MVD station of $x/X_{0} \approx 0.3 \%$ will not be exceed with the current sensor arrangement. For the other MVD stations, the material budget limit of $x/X_{0} \approx 0.5 \%$ will be met using advanced technologies for the construction of the Flex Print Cables required to transport the data send by the sensors to the first stage of front-end electronics positioned on the half station support structures. + + +\begin{thebibliography}{9} % Use for 1-9 references +%\begin{thebibliography}{99} % Use for 10-99 references + +\bibitem{1} +F. Morel et al. ``MISTRAL and ASTRAL: two CMOS Pixel Sensor architectures suited to the Inner Tracking System of the ALICE experiment'', 2014 JINST 9 C01026 + +\end{thebibliography} + + + + + +\end{document} + -- 2.43.0