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gas_handling_system [2013/12/26 14:54] pereira [Removing Gas from Focal Plane Detectors] |
gas_handling_system [2023/05/11 11:29] pereira |
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====== Detector gas handling system ====== | ====== Detector gas handling system ====== | ||
+ | * [[#General Information for gas handling systems]] | ||
+ | * [[# | ||
+ | * [[#Tracking Gas bottles pressures|Tracking Gas bottles pressures from Barney]] | ||
+ | * [[# | ||
- | ===== General Information ===== | + | ===== General Information |
- | Required controls and monitoring | + | |
- | * **LabView gas handling system** application | + | |
- | * PanelMate **S800vac.MT2 page 07**: Focal Plane Detector | + | |
- | The gas handling systems for both Focal Plane gas-filled detectors – the [[Detectors# | + | 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 |
+ | * [[installation_fp_sci|Venting/ | ||
+ | * [[venting_pumping_intermediate_image_box|Venting/ | ||
- | Note that since the same roughing pump drives the gas handling systems | + | ===== Preparation of Gas bottles |
- | ===== LabView Control Program ===== | + | ==== In Data-U4 |
- | To start the gas handling system control application, | + | * Ensure |
- | + | * Confirm that the focal plane chamber is under vacuum | |
- | * A log file should be specified before operating the gas handling system | + | |
- | | + | |
- | | + | |
- | | + | |
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- | | + | |
- | * 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) | + | |
- | + | ||
- | * 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 | + | |
- | * 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 |
- | | + | |
- | | + | |
- | | + | |
- | | + | |
+ | | ||
{{: | {{: | ||
{{: | {{: | ||
- | ===== 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 | + | |
- | + | ||
- | * 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 | + | |
- | + | ||
- | * 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/regulation | + | |
- | * 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) | + | |
- | | + | |
- | * 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 pressure as indicated by the display labeled P.T. #2 reads below a couple | + | |
- | | + | |
- | | + | |
- | * 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 22** | + | |
- | + | ||
- | * Open **valves 10 and 15** | + | |
- | + | ||
- | * Open **valve 12**; the flow reading at MFC #2 should jump momentarily | + | |
- | + | ||
- | * Open **valve 17**; the flow reading at MFC #3 should jump momentarily | + | |
- | + | ||
- | * Fill CRDCs | + | |
- | * 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 | + | |
- | * 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 S3 vault and close main valves on [[# | ||
+ | {{: | ||
+ | ===== Replacing Gas bottles ===== | ||
+ | In preparation |