From 3d067a2f3e5249588fea2b666159b952132fed5a Mon Sep 17 00:00:00 2001 From: Tyler Lemon Date: Tue, 26 Nov 2019 09:28:21 -0500 Subject: [PATCH] correct RICH N2 flow rate, flow meter location In "Services" subsection, corrected N2 flow rate and added text specifying that the nitrogen flow meters are outside of RICH on a gas panel. --- rich/rich-nim.tex | 8 ++++---- 1 file changed, 4 insertions(+), 4 deletions(-) diff --git a/rich/rich-nim.tex b/rich/rich-nim.tex index 833c3e03..eea269eb 100644 --- a/rich/rich-nim.tex +++ b/rich/rich-nim.tex @@ -617,7 +617,7 @@ \subsection{Services} The CLAS12 RICH requires various services, namely power, cooling, and gas purge whose number of lines has to be minimized and installed outside of the CLAS12 acceptance. A continuous nitrogen flow, supplied by the Hall~B gas distribution system, is provided in order to keep the relative humidity inside the RICH vessel at the few percent -level. The flow is set to about 60~l/m to ensure a complete inner volume exchange in a few hours. +level. The flow is set to about 40~l/m to ensure a complete inner volume exchange in a few hours. %The nitrogen is supplied by the Hall-B distribution system based on a large dewar filled of liquid nitrogen. A backup system has been realized by a stack of nitrogen bottles to allow for up to 3 days of gas flow in case of failure of the primary distribution system. @@ -1010,7 +1010,7 @@ \section{RICH Slow Control and Interlocks} \label{fig:Online_FPGATempMap} \end{figure} -The locations of the temperature and humidity sensors, and the air and nitrogen flow meters inside the electronics +The locations of the temperature and humidity sensors, and the air and nitrogen inlet paths inside the electronics panel and nitrogen volume are shown in Figs.~\ref{Fig:RICH_sensors_e_panel} and \ref{Fig:RICH_sensors_nitrogen}, respectively. The inner temperature of the electronics panel ranges between $\rm 38.5^\circ$C and $\rm 44.5^\circ$C moving from the bottom towards the top of the module, whereas the external temperature stays below $\rm 34.5^\circ$C, @@ -1040,8 +1040,8 @@ \section{RICH Slow Control and Interlocks} %\label{fig:Online_EPanelTempStrip} %\end{figure} -The nitrogen flow and the RICH internal relative humidity are measured by several probes installed inside the -detector. +The RICH internal relative humidity is measured by several probes installed inside the detector and nitrogen flow is +measured by external flow meters at the RICH nitrogen supply gas panel. %A strip chart of the reported humidity spanning a time interval of several days is shown in Fig.\ref{fig:Online_Humidity}. An alarm is sent out in case the humidity exceeds 5\% or in case the nitrogen flow drops below the normal value. In the latter case, the backup system starts working to restore the normal flow level and to ensure safe humidity