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Revision: 1.2, Fri Apr 11 22:13:06 2003 UTC (21 years, 5 months ago) by saw Branch: MAIN CVS Tags: mar2005, HEAD Branch point for: hks05 Changes since 1.1: +16 -9 lines (hcf) Some corrections |
\documentclass{chowto} \title{Operating the HMS Vacuum Window Shutter} \howtotype{user} % ``expert'', ``user'', ``reference'' %\experiment{Name of experiment} % Optional \author{H. Fenker} \category{hms} % Subject area of this document %\maintainer{Name of person maintaining document} % Optional \date{April 11, 2003} % Can use \today as the argument \begin{document} \begin{abstract} This document describes the operational procedures for opening and closing the HMS Vacuum Window Shutter. \end{abstract} \section{Related {\it Howtos}} The following Hall-C {\it Howto} documents may be helpful. %--DELETE THOSE DOCUMENTS MENTIONED HERE WHICH ARE IRRELEVANT User Level Documents- \par \indent \indent Base Equipment Checklist \cite{howto:base_equip_checklist} \par \indent \indent Operating the HMS Shield House Door \cite{howto:open_hms_door} \par \indent \indent Operating the SOS Shield House Door \cite{howto:open_hms_door} \section{Shutter Description} The HMS vacuum volume extends from near the scattering chamber, through the three quadrupoles and the dipole, up to the thin aluminum vacuum window just upstream of the first HMS drift chamber. Because of the considerable stored energy in such a large vacuum volume, it is necessary to protect personnel working in the HMS shield house from the possibiliity of a catastrophic failure of this vacuum. See Figure \ref{fig:hms_detector_vacuum}. \begin{figure}[hbp] \centering \includegraphics[width=6in,height=5in]{open_hms_shutter-hms_detector_vacuum.eps} \caption{The HMS vacuum window in the HMS spectrometer hut. \label{fig:hms_detector_vacuum}} \end{figure} Protection is provided by a 1~inch thick aluminum plate which covers the large vacuum window in the HMS shield house. This plate slides up and down in an assembly which is attached to the end of the vacuum vessel. Movement of the shutter is managed by a motor which is controlled from a control box on the outside of the shield house, on the left side of the door. \section{Interlocks} An interlock prevents access to the HMS detector hut unless the safety shutter has been moved to its `down' position, such that it covers the vacuum window. This is to prevent people from accidentally touching the large vacuum window, or suffering hearing loss should there be a catastrophic failure of the window. The shutter cannot be retracted unless the door is closed. The door cannot be opened unless the shutter is already inserted. \section{Shutter Operation} To close the shutter, press (and hold for a few seconds) the button labeled ``DOWN'' on the shutter control box. This will start insertion of the shutter. After a few seconds the light indicating ``OUT'' will turn off. It takes about two minutes for the shutter to move into place. When it does, the light labeled ``IN'' will glow. This indicates that the shutter is inserted and the door may be opened. To open (i.e. {\it raise} the shutter, after the HMS shield house door has been fully closed, press the button labeled ``UP'' and hold it for a few seconds. The ``IN'' light will dim as the shutter moves away from the fully inserted position. Full retraction takes about two minutes. When the shutter is fully retracted, the ``OUT'' light will glow. Usually the shutter is retracted by MCC operators after they have swept the interior of the HMS shield house and closed the door. Experimenters should watch the operators, using the hall survey TV cameras, to make certain that they complete this step during any sweep of the hall. If the operators complete the sweep of the hall without opening the shutter, you will have to make a controlled access and open the shutter yourself. If you enter the HMS shield house during Controlled Access, you are responsible for closing the door and raising the shutter yourself. ``IN'' and ``OUT'' shutter status lights are located both on the shutter control box and on the top left panel of the Counting House main console. You can check the status of the shutter from the Counting House via these lights. \end{document} % Revision history: % $Log: open_hms_shutter.tex,v $ % Revision 1.2 2003/04/11 23:13:06 saw % (hcf) Some corrections % % Revision 1.1 2003/04/04 16:01:38 saw % Initial Checkin %
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