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gas_handling_system [2013/12/13 21:16] pereira |
gas_handling_system [2013/12/14 16:05] pereira [General Information] |
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===== General Information ===== | ===== General Information ===== | ||
Required controls and monitoring | Required controls and monitoring | ||
- | * LabView gas handling system application | + | |
- | * PanelMate S800vac.MT2 page 07: Focal Plane Detector | + | * PanelMate |
The gas handling systems for both Focal Plane gas-filled detectors – the Ion Chamber and the CRDCs – are remotely controlled via a single LabView application running on the computer S800FP-PC in the S3 vault. This computer can be accessed remotely via the devop1 computer in Data-U6. | The gas handling systems for both Focal Plane gas-filled detectors – the Ion Chamber and the CRDCs – are remotely controlled via a single LabView application running on the computer S800FP-PC in the S3 vault. This computer can be accessed remotely via the devop1 computer in Data-U6. | ||
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* Once both detectors are empty, this application can be closed with the “X” button on the upper right corner of the window. | * Once both detectors are empty, this application can be closed with the “X” button on the upper right corner of the window. | ||
- | {{: | + | {{: |
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* Ensure that the main valves on the gas bottles are open | * Ensure that the main valves on the gas bottles are open | ||
* Ensure that the gas bottles are not empty | * Ensure that the gas bottles are not empty | ||
- | * The gas regulators are not normally adjusted. | + | * The gas regulators are not normally adjusted. They should all be set to provide a pressure around 20 psi. |
* The bottle supplying the P-10 gas for the ion chamber is secured to the cross-brace of the south support for the focal plane chamber. | * The bottle supplying the P-10 gas for the ion chamber is secured to the cross-brace of the south support for the focal plane chamber. | ||
- | * The bottle supplying | + | * The bottle supplying |
- | * The bottle supplying isobutane (C4H10) for the CRDCs is secured to the south support post for the focal plane chamber. | + | * The bottle supplying isobutane (C< |
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* Follow instructions under [[# | * Follow instructions under [[# | ||
+ | |||
* Monitor the pressure of the focal plane vacuum chamber (as read out via the I264IG ion gauge) while detectors are being filled with gas; the pressure normally stays below 5E-5 Torr. | * Monitor the pressure of the focal plane vacuum chamber (as read out via the I264IG ion gauge) while detectors are being filled with gas; the pressure normally stays below 5E-5 Torr. | ||
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* To zero this display: | * To zero this display: | ||
* Click on the **Slot 3 (PT1)** tab to access the details page for PT #1 | * Click on the **Slot 3 (PT1)** tab to access the details page for PT #1 | ||
- | * Click the Zero Sensor button | + | * 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 | + | * 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 **valve 6** | ||
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* 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 | + | * If necessary, the filling process can be stopped at any time by pressing the valve button labeled |
* Open **valve 9** | * Open **valve 9** | ||
* The filling process will take several minutes | * The filling process will take several minutes | ||
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* When the detector is filled, close **valve 5** | * When the detector is filled, close **valve 5** | ||
- | Filling CRDC1 and CRDC2 with Gas | ||
- | Follow instructions under PREPARATIONS FOR FILLING DETECTORS WITH GAS above | ||
- | Monitor the pressure of the focal plane vacuum chamber (as read out via the I264IG ion gauge) while detectors are being filled with gas; the pressure normally stays below 5E-5 Torr. | ||
- | Confirm that the detector pressure as indicated by the display labeled P.T. #2 reads below a couple of Torr | ||
- | To zero this display: | ||
- | Click on the Slot 4 (PT2) tab to access the details page for PT #2 | ||
- | 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 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/ | ||
- | 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) | ||
- | 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 | ||
- | When the detector is filled, close valve 21 | ||
+ | ===== Filling CRDC1 and CRDC2 with Gas ===== | ||
+ | |||
+ | * Follow instructions under [[# | ||
+ | |||
+ | * Monitor the pressure of the focal plane vacuum chamber (as read out via the I264IG ion gauge) while detectors are being filled with gas; the pressure normally stays below 5E-5 Torr. | ||
+ | |||
+ | * Confirm that the detector pressure as indicated by the display labeled P.T. #2 reads below a couple of Torr | ||
+ | * To zero this display: | ||
+ | * Click on the **Slot 4 (PT2)** tab to access the details page for PT #2 | ||
+ | * 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/ | ||
+ | * 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) | ||
+ | * 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 | ||
+ | |||
+ | * 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) 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 is closed to isolate focal plane vacuum chamber from spectrograph | ||
+ | |||
+ | * 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** | ||
+ | |||
+ | * **IMPORTANT: | ||
+ | |||
+ | * Empty Ion Chamber to a pressure at or below the pressure of the CRDCs | ||
+ | * 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 | ||
+ | * Open **valve 25** | ||
+ | * Open **valve 24** | ||
+ | * Wait for the pressure in both detectors as indicated by the displays labeled P.T. #1 and P.T. #2 to reach 0.5 Torr or less; this process will take at least an hour | ||
+ | |||
+ | * Close **valves 9 and 25** | ||
+ | |||
+ | * Close **valves 8 and 24** | ||
- | Removing Gas from Focal Plane Detectors | + | * Open **valves 6 and 22** |
- | Monitor the pressure of the focal plane vacuum chamber (as read out via the I264IG ion gauge) while gas is being removed from detectors; the pressure normally stays below 5E-5 Torr | + | * Enter vault and close main valves on gas bottles: |
- | 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 is closed to isolate focal plane vacuum chamber from spectrograph | + | |
- | 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 | + | |
- | IMPORTANT: | + | |
- | Empty Ion Chamber to a pressure at or below the pressure of the CRDCs | + | |
- | 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 | + | |
- | Open valve 25 | + | |
- | Open valve 24 | + | |
- | Wait for the pressure in both detectors as indicated by the displays labeled P.T. #1 and P.T. #2 to reach 0.5 Torr or less; this process will take at least an hour | + | |
- | Close valves 9 and 25 | + | |
- | Close valves 8 and 24 | + | |
- | Open valves 6 and 22 | + | |
- | Enter vault and close main valves on gas bottles: | + | |