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gas_handling_system [2017/01/22 16:43] pereira [Detector gas handling system] |
gas_handling_system [2019/10/19 12:08] pereira [Tracking Gas bottles pressures] |
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====== Detector gas handling system ====== | ====== Detector gas handling system ====== | ||
- | General | + | * [[#General |
- | ===== General Information ===== | + | * [[#LabView Control Program for focal plane detectors]] |
+ | * [[# | ||
+ | * [[#Filling Ion Chamber with Gas]] | ||
+ | * [[#Filling CRDC1 and CRDC2 with Gas]] | ||
+ | * [[#Removing Gas from Focal Plane Detectors]] | ||
+ | * [[Venting/ | ||
+ | * [[#Tracking Gas bottles pressures|Tracking Gas bottles pressures from Barney]] | ||
+ | * [[# | ||
+ | |||
+ | ===== General Information | ||
+ | The gas handling systems for both Focal Plane gas-filled detectors – the [[Detectors# | ||
+ | |||
+ | 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, | ||
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+ | 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 | + | ===== LabView Control Program |
+ | To start the gas handling system control application, | ||
- | Note that since the same roughing pump drives | + | * The LabView program controls |
+ | * Go to Initialization tab | ||
+ | * Confirm | ||
- | ===== LabView Control Program ===== | ||
- | To start the gas handling system control application, | ||
* 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 " | + | * 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 |
==== In Data-U6 ==== | ==== In Data-U6 ==== | ||
* Ensure **I265GV** is closed (in PanelMate **S800vac.ui page 07**) to isolate focal plane vacuum chamber from the rest of the beamline | * Ensure **I265GV** is closed (in PanelMate **S800vac.ui page 07**) to isolate focal plane vacuum chamber from the rest of the beamline | ||
* Confirm that the focal plane chamber is under vacuum | * Confirm that the focal plane chamber is under vacuum | ||
- | * Confirm that the only open gas handling system valves are **4, 5, 6, 20, 21, and 22** | + | * Confirm that the only open gas handling system valves are **4, 5, 6, 7, 20, 21, 22 and 23** |
* (Check section on [[vacuum control|vacuum control]] for further details.) | * (Check section on [[vacuum control|vacuum control]] for further details.) | ||
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* The display unit for the pressure at the pump has a needle indicator and is mounted under the [[Stations# | * The display unit for the pressure at the pump has a needle indicator and is mounted under the [[Stations# | ||
* Ensure that the main valves on the gas bottles are open (see pictures below) | * Ensure that the main valves on the gas bottles are open (see pictures below) | ||
+ | * Open valves downstream of regulators in each bottle | ||
* Ensure that the gas bottles are not empty | * Ensure that the gas bottles are not empty | ||
* The gas regulators are not normally adjusted. They should all be set to provide a pressure around 20 psi | * The gas regulators are not normally adjusted. They should all be set to provide a pressure around 20 psi | ||
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* Click the **Valves** tab at the top of the LabView window to return to the overview display of the gas handling system | * Click the **Valves** tab at the top of the LabView window to return to the overview display of the gas handling system | ||
- | * Close **valve 6** | + | * Close **valves |
* Open **valve 2**; the flow reading at MFC #1 should jump momentarily | * Open **valve 2**; the flow reading at MFC #1 should jump momentarily | ||
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* Click on the tab labeled **Slot 8 (M-card) IC** to access the page with the pressure set point control | * Click on the tab labeled **Slot 8 (M-card) IC** to access the page with the pressure set point control | ||
* Enter the desired pressure (typically 300 Torr) in the field under the knob labeled Set Point | * Enter the desired pressure (typically 300 Torr) in the field under the knob labeled Set Point | ||
+ | * Click button labeled **Update Set Point** | ||
* Click button labeled **Return to AUTO Mode** on left to start filling/ | * Click button labeled **Return to AUTO Mode** on left to start filling/ | ||
* Click the **Valves** tab at the top of the LabView window to return to the overview display of the gas handling system to monitor filling. The flow readings for MFC #1 will increase and eventually disappear as the readout value overflows the display field (this is normal behavior) | * Click the **Valves** tab at the top of the LabView window to return to the overview display of the gas handling system to monitor filling. The flow readings for MFC #1 will increase and eventually disappear as the readout value overflows the display field (this is normal behavior) | ||
- | * If necessary, the filling process can be stopped at any time by pressing the valve button labeled **Close MFC #1** | ||
* Open **valve 9** | * Open **valve 9** | ||
+ | * If necessary, the filling process can be stopped at any time by pressing the valve button labeled **Close MFC #1** | ||
* The filling process will take several minutes | * The filling process will take several minutes | ||
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* Click the **Valves** tab at the top of the LabView window to return to the overview display of the gas handling system | * Click the **Valves** tab at the top of the LabView window to return to the overview display of the gas handling system | ||
- | * Close **valve 22** | + | * Close **valves |
* Open **valves 10 and 15** | * Open **valves 10 and 15** | ||
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* Fill CRDCs | * Fill CRDCs | ||
* Enter the desired fill pressure and start the automatic filling process | * Enter the desired fill pressure and start the automatic filling process | ||
- | * Click the **Zero Sensor** button | ||
* Click on the tab labeled **Virtual Ch. 0 (CRDC)** to access the page with the pressure set point control | * Click on the tab labeled **Virtual Ch. 0 (CRDC)** to access the page with the pressure set point control | ||
* Enter the desired pressure (typically 40 Torr) in the field under the knob labeled **Set Point** | * Enter the desired pressure (typically 40 Torr) in the field under the knob labeled **Set Point** | ||
+ | * Click button labeled **Update Set Point** | ||
* Click button labeled **Return to AUTO Mode** on left to start filling/ | * Click button labeled **Return to AUTO Mode** on left to start filling/ | ||
* Click the **Valves** tab at the top of the LabView window to return to the overview display of the gas handling system to monitor filling. The flow readings for MFC #2 and MFC #3 will increase. The LabView application controls the gas mixing ratio based on the flow ratio (scaled with a calibration constant) | * Click the **Valves** tab at the top of the LabView window to return to the overview display of the gas handling system to monitor filling. The flow readings for MFC #2 and MFC #3 will increase. The LabView application controls the gas mixing ratio based on the flow ratio (scaled with a calibration constant) | ||
+ | * Open **valve 25** | ||
* If necessary, the filling process can be stopped at any time by pressing the valve button labeled **Close MFCs #2 & #3** | * If necessary, the filling process can be stopped at any time by pressing the valve button labeled **Close MFCs #2 & #3** | ||
- | * Open **valve 25** | ||
* The filling process will take several minutes | * The filling process will take several minutes | ||
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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), |
* 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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* Close **valves 8 and 24** | * Close **valves 8 and 24** | ||
- | * Open **valves 6 and 22** | + | * Open **valves 6, 7, 22 and 23** |
- | * Enter S3 vault and close main valves | + | * Enter S3 vault and close valves |
===== Tracking Gas bottles pressures ===== | ===== Tracking Gas bottles pressures ===== | ||
+ | A rather conservative rule of thumb that helps estimate how much gas will be consumed during a given period of time assumes that the S800 IC detector consumes **~10 psi/day of P10**. Likewise, the CRDCs consume **~10 psi/day of CF4** and **~0.07 lb/day of Isobutane**. | ||
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In order to track the status of the gas bottles for the [[Detectors# | In order to track the status of the gas bottles for the [[Detectors# | ||
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{{: | {{: | ||
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+ | ===== Replacing Gas bottles ===== | ||
+ | In preparation |