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gas_handling_system [2018/04/11 16:13]
pereira [Removing Gas from Focal Plane Detectors]
gas_handling_system [2020/03/01 14:50] (current)
pereira [Tracking Gas bottles pressures]
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 ====== Detector gas handling system ====== ====== Detector gas handling system ======
  
-  * [[#General information]] +  * [[#General information ​for focal-plane gas handling system]] 
-  * [[#LabView Control Program]] +  * [[#LabView Control Program ​for focal plane detectors]] 
-  * [[#Preparation of Gas bottles|Preparation of Gas bottles for filling of detectors]]+  * [[#​Preparation of Gas bottles for filling of focal-plane ​detectors]]
   * [[#Filling Ion Chamber with Gas]]   * [[#Filling Ion Chamber with Gas]]
   * [[#Filling CRDC1 and CRDC2 with Gas]]   * [[#Filling CRDC1 and CRDC2 with Gas]]
   * [[#Removing Gas from Focal Plane Detectors]]   * [[#Removing Gas from Focal Plane Detectors]]
 +  * [[Venting/​pumping Intermediate Image box#​Filling/​Removing gas in Intermediate-image delay PPAC|Filling and removing gas of Intermediate-image delay PPACs]]
   * [[#Tracking Gas bottles pressures|Tracking Gas bottles pressures from Barney]]   * [[#Tracking Gas bottles pressures|Tracking Gas bottles pressures from Barney]]
   * [[#​Replacing Gas bottles]]   * [[#​Replacing Gas bottles]]
  
-===== General Information =====+===== General Information ​for focal-plane gas handling system ​===== 
 +The gas handling systems for both Focal Plane gas-filled detectors – the [[Detectors#​Ionization Chamber|Ionization Chamber]] and the [[Detectors#​Cathode Readout Drift Chambers (CRDC)|CRDCs]] – are remotely controlled via a single LabView application running on the computer [[Software|S800FP-PC]] in the S3 vault. This computer can be accessed remotely from the desktop of computer [[Software#​u6pc5 (data U6)|u6pc5]],​ by clicking in the icon **S800 Vault PC**, or by typing ''​xfreerdp /u:s800 /​v:​s800fp.nscl.msu.edu''​ from a Linux terminal. A terminal will pop-up asking for the s800 password. Once the virtual session in S800FP-PC is open, the gas handling system can be opened by clicking in the corresponding icon on the desktop **FPGHS_TCPIP-II**. This icon opens the local directory ''​C:/​Users/​s800/​Desktop/​FPGHS_TCPIP-II''​. Once there, run the Labview executable **FPGHS_TCPIP-II.exe**.  
 + 
 +The Labview software communicates with a MKS gas handling system through a Moax Nport 5110 terminal server attached to the bottom of the focal-plane chamber. This terminal server has a hostname s800ghts.nscl.msu.edu,​ which currently has an static IP address assigned to it (10.65.40.135). When running Labview, go to the Initialization tab and make sure that the terminal server address (IP) and port number (2001) is correct. 
 + 
 + 
 + 
 + 
 + 
 +Note that since the same roughing pump drives the gas handling systems for both gas-filled detectors, extra precautions must be taken to protect one detector from the pressure of the other detector. The fact that the same pump drives both systems is not indicated on the graphics for the LabView control application 
 Required controls and monitoring Required controls and monitoring
   * LabView gas handling system application **FPGHS_TCPIP-II.vi** ​   * LabView gas handling system application **FPGHS_TCPIP-II.vi** ​
   * PanelMate **S800vac.ui page 07**: Focal Plane Detector   * PanelMate **S800vac.ui page 07**: Focal Plane Detector
  
-The gas handling systems ​for both Focal Plane gas-filled ​detectors ​– the [[Detectors#​Ionization Chamber|Ionization Chamber]] and the [[Detectors#​Cathode Readout Drift Chambers (CRDC)|CRDCs]] – are remotely controlled via a single ​LabView ​application running ​on the computer ​[[Software|S800FP-PC]] ​in the S3 vault. This computer can be accessed remotely from the desktop ​of computer [[Software#​u6pc5 (data U6)|u6pc5]],​ by clicking in the icon **S800 Vault PC**, or by typing ''​xfreerdp /u:s800 /​v:​35.9.56.104''​ from a Linux terminal. A terminal will pop-up asking for the s800 password. Once the virtual session in S800FP-PC is open, the gas handling system can be opened by clicking in the corresponding icon on the desktop **FPGHS_TCPIP-II**. This icon opens the local directory ''​C:/​Users/​s800/​Desktop/​FPGHS_TCPIP-II''​. Once there, run the Labview executable **FPGHS_TCPIP-II.exe**+===== LabView Control Program ​for focal plane detectors ​===== 
 +To start the gas handling system control application,​ click on the LabView ​icon **FPGHS_TCPIP_Corrected_V01** ​on the [[Software|S800FP-PC]] desktop.
  
-Note that since the same roughing pump drives ​the gas handling ​systems for both gas-filled detectors, extra precautions must be taken to protect one detector from the pressure of the other detectorThe fact that the same pump drives both systems ​is not indicated on the graphics for the LabView control application+  * The LabView program controls ​the gas handling ​system through a Moax terminal server. You have to verify that the address is correct 
 +      * Go to Initialization tab 
 +      * Confirm ​that the IP address ​is 10.65.40.135 (or s800ghts) and the port number is 2001
  
-===== LabView Control Program ===== 
-To start the gas handling system control application,​ click on the LabView icon **FPGHS_TCPIP_Corrected_V01** on the [[Software|S800FP-PC]] desktop. 
  
   * A log file should be specified before operating the gas handling system   * A log file should be specified before operating the gas handling system
       * A window automatically pops up asking for the name of the log file when the program starts       * A window automatically pops up asking for the name of the log file when the program starts
-      * Use the number of the current experiment (or "​test"​) as the name of the log file and save in file /​intranet/​files/​departments/operations/s800/TO_BE_SPECIFIED+      * Use the number of the current experiment (or the date) as the name of the log file and save in the default directory **/projects/s800/Gas logs**
       * The On indicator next to Is VI running? will flash until a log file is specified and the program initiates communications with the hardware       * The On indicator next to Is VI running? will flash until a log file is specified and the program initiates communications with the hardware
  
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-===== Preparation of Gas bottles =====+===== Preparation of Gas bottles ​for filling of focal-plane detectors ​=====
  
 ==== In Data-U6 ==== ==== In Data-U6 ====
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   * Open **valves 5 and 21**   * Open **valves 5 and 21**
  
-  * **IMPORTANT:** CLOSE **VALVE 25** to protect CRDCs from Ion Chamber pressure+  * **IMPORTANT**: Before opening valve 8 (next step), ​CLOSE **VALVE 25** to protect CRDCs from Ion Chamber pressure
  
   * Empty Ion Chamber to a pressure at or below the pressure of the CRDCs   * Empty Ion Chamber to a pressure at or below the pressure of the CRDCs
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 ===== Tracking Gas bottles pressures ===== ===== Tracking Gas bottles pressures =====
 +A rather conservative rule of thumb that helps estimate how much gas will be consumed during the course of an experiment assumes that when the detectors are filled and with gas running through them, the S800 IC detector consumes **~10 psi/day of P10**, and the CRDCs consume **~10 psi/day of CF4** and **~0.07 lb/day of Isobutane**. The process of filling the detectors, is approximately equivalent to 1 day of gas consumption during normal operations.
 +
 +
 In order to track the status of the gas bottles for the [[Detectors#​Ionization Chamber|ionization chamber]], the  [[Detectors#​Cathode Readout Drift Chambers (CRDC)|CRDCs]],​ and the [[Detectors#​[Tracking Parallel Plate Avalanche Counters (TPPAC)]|TPPAC]],​ it is possible to monitor their remaining pressures from Barney. Just open the **A1900** page, then **Tools**, and then **Gas Status**. The following window will be displayed: In order to track the status of the gas bottles for the [[Detectors#​Ionization Chamber|ionization chamber]], the  [[Detectors#​Cathode Readout Drift Chambers (CRDC)|CRDCs]],​ and the [[Detectors#​[Tracking Parallel Plate Avalanche Counters (TPPAC)]|TPPAC]],​ it is possible to monitor their remaining pressures from Barney. Just open the **A1900** page, then **Tools**, and then **Gas Status**. The following window will be displayed:
 +
 +The gas content of each bottle is tracked by measuring the pressure in regulators (e.g. P10 and CF4) or the weight of the bottle on a scale. Both types of measured values are encoded in EPICS PVs, allowing remote monitoring of the gas available. There are two alarm levels (low alarm and high alarm) that can be adjusted using the corresponding EPICS PV. For instance, for the isobutane bottles (5 lb net weight), the low- and high-level alarms trigger at 1 lb and 0.5 lb, respectively.
 +
 +When installing a full bottle in a scale (e.g. isobutane), it is important to follow a procedure to account for the differences between the weight measured by the scale, and the actual gross weight. After removing an empty bottle, proceed as follows:
 +
 +Adjusting the pressured reading from a scale (for instance isobutane) requires some special guidelines. In the case of isobutane, the following EPICs PVs are involved:
 +  * Check the weight marked in the scale when it is empty (no bottle). If different than zero, press "set zero" and ensure that it marks 0 lb
 +  * Check the gross and net weight in the bottle (as seen in the labels)
 +  * Install the bottle in the scale and check its weight. ​
 +  * Update the following EPICS PVs with the correct values:
 +     * I265DGWN: net weight, as marked in the bottle (e.g. 5 lb)
 +     * I265DGWG: gross weight, as marked in the bottle (e.g. 41.6 lb)
 +     * I265DGWS: weight, as read from the scale
 +     * I265DGWC: correction factor used to match the scale weight and gross weight when the full bottle is installed.
 +     * I265DGW: net weight deduced from the scale
  
  
gas_handling_system.1523477613.txt.gz · Last modified: 2018/04/11 16:13 by pereira