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gas_handling_system [2013/12/26 14:49] pereira [In the S3 vault] |
gas_handling_system [2023/05/11 11:17] pereira [General Information for gas handling systems] |
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====== Detector gas handling system ====== | ====== Detector gas handling system ====== | ||
- | ===== General | + | * [[#General |
- | Required controls and monitoring | + | |
- | * **LabView | + | |
- | * PanelMate **S800vac.MT2 page 07**: Focal Plane Detector | + | * [[# |
- | The gas handling systems | + | ===== General Information for gas handling systems |
- | 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 | + | The gas handling systems for the gaseous detectors in both intermediate-image and focal-plane boxes are operated remotely through CS studio. Their pages can be found on the EXP network through FRIB EXP Main → S800 → GHS Pages (Secondary Pages). Detailed instructions are found in the following pages: |
- | ===== LabView Control Program ===== | + | |
- | To start the gas handling system control application, | + | |
- | * A log file should be specified before operating the gas handling system | + | ===== Preparation of Gas bottles |
- | * A window automatically pops up asking | + | |
- | * Use the number of the current experiment (or " | + | |
- | * The On indicator next to Is VI running? will flash until a log file is specified and the program initiates communications with the hardware | + | |
- | * Click the **Valves** tab at the top of the LabView window to display the overview of the gas handling system (see Figure below) | + | ==== In Data-U4 ==== |
- | * The triangles on the valve control buttons (as well as the square valve status indicators near the control buttons) are red to indicate that a valve is closed (e.g., control 25 for the CRDC return above) and green to indicate a valve is open (e.g., control 22 for the CRDC bypass above) | + | * Ensure **RBT_BTS34: |
- | + | * Confirm that the focal plane chamber is under vacuum | |
- | * The gas handling control application should always remain open during the entire time either detector is filled with gas to ensure the log file is continuously updated | + | |
- | + | ||
- | * Once both detectors are empty, this application can be closed with the “X” button on the upper right corner of the window. | + | |
- | + | ||
- | {{: | + | |
- | + | ||
- | + | ||
- | ===== Preparation of Gas bottles ===== | + | |
- | + | ||
- | ==== In Data-U6 ==== | + | |
- | * Ensure **I265GV** is closed | + | |
- | * 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** | + | |
- | * (Check section on [[vacuum control|vacuum control]] for further details.) | + | |
==== In the S3 vault ==== | ==== In the S3 vault ==== | ||
- | | + | |
- | | + | |
- | | + | |
- | * 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) |
- | * Ensure that the gas bottles are not empty | + | * Open valves downstream of regulators in each bottle |
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- | | + | |
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- | | + | |
+ | | ||
{{: | {{: | ||
{{: | {{: | ||
- | ===== Filling Ion Chamber with Gas ===== | + | ===== Tracking |
- | + | A rather conservative rule of thumb that helps estimate how much gas will be consumed during | |
- | * Follow instructions under [[# | + | |
- | + | ||
- | * Monitor the pressure of the focal plane vacuum chamber (as read out via the I264IG ion gauge in PanelMate **S800vac.MT2 page 07**) while detectors are being filled with gas; the pressure normally stays below 5E-5 Torr. | + | |
- | + | ||
- | * Confirm | + | |
- | * To zero this display: | + | |
- | * Click on the **Slot 3 (PT1)** tab to access the details page for PT #1 | + | |
- | * Click the **Zero Sensor** button | + | |
- | * 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** | + | |
- | + | ||
- | * Open **valve 2**; the flow reading at MFC #1 should jump momentarily | + | |
- | + | ||
- | * Fill Ion chamber | + | |
- | * Enter the desired fill pressure and start the automatic filling process | + | |
- | * 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 | + | |
- | * 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) | + | |
- | * If necessary, the filling process can be stopped at any time by pressing | + | |
- | * Open **valve 9** | + | |
- | * The filling process will take several minutes | + | |
- | + | ||
- | * When the detector is filled, close **valve 5** | + | |
- | + | ||
- | + | ||
- | + | ||
- | ===== Filling CRDC1 and CRDC2 with Gas ===== | + | |
- | + | ||
- | * Follow instructions under [[# | + | |
- | + | ||
- | * Monitor | + | |
- | + | ||
- | * Confirm that the detector | + | |
- | | + | |
- | | + | |
- | * Click the **Zero Sensor** button | + | |
- | * Click the **Valves** tab at the top of the LabView window to return to the overview display of the gas handling system | + | |
- | + | ||
- | | + | |
- | + | ||
- | * Open **valves 10 and 15** | + | |
- | + | ||
- | * Open **valve 12**; the flow reading at MFC #2 should jump momentarily | + | |
- | + | ||
- | | + | |
- | + | ||
- | * Fill CRDCs | + | |
- | * Enter the desired fill pressure | + | |
- | | + | |
- | * 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** | + | |
- | * Click button labeled **Return to AUTO Mode** on left to start filling/regulation | + | |
- | | + | |
- | * If necessary, the filling | + | |
- | * Open **valve 25** | + | |
- | * The filling | + | |
- | + | ||
- | * When the detector is filled, close **valve 21** | + | |
- | + | ||
- | + | ||
- | ===== Removing Gas from Focal Plane Detectors ===== | + | |
- | + | ||
- | * Monitor the pressure of the focal plane vacuum chamber (as read out via the I264IG ion gauge in PanelMate **S800vac.MT2 page 07**) while gas is being removed from detectors; the pressure normally stays below 5E-5 Torr | + | |
- | + | ||
- | * Ensure that the system is in the normal state for flowing gas through the detectors | + | |
- | * Confirm that the focal plane chamber is under vacuum | + | |
- | * Confirm that **the only open** gas handling system valves are **2, 4, and 9 for the Ion Chamber** and **10, 12, 15, 17, 20, and 25 for the CRDCs** | + | |
- | * Confirm that the detector pressures as indicated by the displays labeled P.T. #1 for the Ion Chamber and P.T. #2 for the CRDCs show the correct fill values (typically 300 Torr and 40 Torr, respectively) | + | |
- | + | ||
- | * Ensure that I265GV | + | |
- | + | ||
- | * Stop the gas flow into both detectors by clicking valve buttons labeled **Close MFC #1** and **Close MFCs #2 & #3** | + | |
- | + | ||
- | * Isolate the gas supply by closing **valves 2, 12, 17, 10, and 15** | + | |
- | * Open **valves 5 and 21** | ||
- | | + | In order to track the status of the gas bottles for the [[Detectors# |
- | * Empty Ion Chamber to a pressure | + | The gas content of each bottle is tracked by measuring the pressure |
- | * Open **valve 8** | + | |
- | * Wait for the Ion Chamber pressure to reach or drop below the pressure in the CRDCs; this process will take several minutes | + | |
- | * Finish emptying both detectors | + | When installing a full bottle in a scale (e.g. isobutane), it is important to follow a procedure to account |
- | * Open **valve 25** | + | |
- | * Open **valve 24** | + | |
- | * Wait for the pressure in both detectors as indicated | + | |
- | + | ||
- | * Close **valves 9 and 25** | + | |
- | | + | 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: |
+ | | ||
+ | | ||
+ | | ||
+ | | ||
+ | * 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 | ||
- | * Open **valves 6 and 22** | ||
- | * Enter vault and close main valves on gas bottles: | ||
+ | {{: | ||
+ | ===== Replacing Gas bottles ===== | ||
+ | In preparation |