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gas_handling_system [2013/12/13 20:59] pereira |
gas_handling_system [2013/12/14 16:10] 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 [[Detectors# |
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 | 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 | ||
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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. | ||
- | {{: | + | {{: |
- | Preparation of Gas bottles | + | ===== Preparation of Gas bottles |
- | In Data-U6 | + | ==== In Data-U6 |
- | Ensure I265GV is closed to isolate focal plane vacuum chamber from the rest of the beamline | + | |
- | 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 | + | |
- | In the S3 vault | + | |
- | Ensure that the gas handling system roughing pump is running and has a good vacuum | + | |
- | The pump sits on the floor under the focal plane behind the south support post (PICTURE GOES HERE) | + | |
- | The display unit for the pressure at the pump has a needle indicator and is mounted under the focal plane on the south support post (PICTURE GOES HERE) | + | |
- | Ensure that the main valves on the gas bottles are open | + | |
- | Ensure that the gas bottles are not empty | + | |
- | The gas regulators are not normally adjusted. | + | |
- | 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 CF4 (tetrafluoromethane) gas for the CRDCs is secured to the cross-brace of the south support for the focal plane chamber. | + | |
- | The bottle supplying isobutane (C4H10) for the CRDCs is secured to the south support post for the focal plane chamber. | + | |
- | Filling Ion Chamber | + | ==== In the S3 vault ==== |
+ | * Ensure that the gas handling system roughing pump is running and has a good vacuum | ||
+ | * The pump sits on the floor under the focal plane behind the south support post | ||
+ | * The display unit for the pressure at the pump has a needle indicator and is mounted under the focal plane on the south support post | ||
+ | * Ensure that the main valves on the gas bottles are open | ||
+ | * 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 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 CF< | ||
+ | * The bottle supplying isobutane (C< | ||
- | Follow instructions under PREPARATION 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. #1 reads below a couple of Torr | ||
- | 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 the valve button labeled Close MFC #1 | ||
- | Open valve 9 | ||
- | The filling process will take several minutes | ||
- | When the detector is filled, close valve 5 | ||
+ | ===== Filling Ion Chamber with Gas ===== | ||
- | Filling CRDC1 and CRDC2 with Gas | + | * Follow instructions under [[# |
- | 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. |
- | 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 | + | |
+ | * Confirm that the detector pressure as indicated by the display labeled P.T. #1 reads below a couple of Torr | ||
+ | * 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 | ||
- | Removing Gas from Focal Plane Detectors | + | * Close **valve 6** |
- | 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 | + | * Open **valve 2**; the flow reading at MFC #1 should jump momentarily |
- | Ensure that the system is in the normal state for flowing gas through the detectors | + | |
- | Confirm that the focal plane chamber is under vacuum | + | * Fill Ion chamber |
- | 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 | + | * Enter the desired fill pressure and start the automatic filling process |
- | 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) | + | * Click on the tab labeled **Slot 8 (M-card) IC** to access the page with the pressure set point control |
- | Ensure that I265GV is closed to isolate focal plane vacuum chamber from spectrograph | + | * Enter the desired pressure (typically 300 Torr) in the field under the knob labeled Set Point |
- | Stop the gas flow into both detectors by clicking valve buttons labeled Close MFC #1 and Close MFCs #2 & #3 | + | * Click button labeled **Return to AUTO Mode** on left to start filling/ |
- | Isolate the gas supply by closing valves 2, 12, 17, 10, and 15 | + | * 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 valves 5 and 21 | + | * If necessary, the filling process can be stopped at any time by pressing the valve button labeled **Close MFC #1** |
- | IMPORTANT: | + | * Open **valve 9** |
- | Empty Ion Chamber to a pressure at or below the pressure of the CRDCs | + | * The filling process will take several minutes |
- | 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 | + | * When the detector is filled, close **valve 5** |
- | 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 | + | ===== Filling CRDC1 and CRDC2 with Gas ===== |
- | Close valves 9 and 25 | + | |
- | Close valves 8 and 24 | + | * Follow instructions under [[# |
- | Open valves 6 and 22 | + | |
- | Enter vault and close main valves on gas bottles: | + | * 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 | ||
+ | | ||
+ | | ||
+ | | ||
+ | |||
+ | * 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 | ||
+ | |||
+ | * Isolate the gas supply by closing | ||
+ | |||
+ | * Open **valves 5 and 21** | ||
+ | |||
+ | * **IMPORTANT:** CLOSE **VALVE 25** to protect CRDCs from Ion Chamber pressure | ||
+ | |||
+ | * Empty Ion Chamber to a pressure at or below the pressure of the CRDCs | ||
+ | | ||
+ | | ||
+ | |||
+ | * Finish emptying both detectors | ||
+ | | ||
+ | | ||
+ | | ||
+ | |||
+ | * Close **valves 9 and 25** | ||
+ | |||
+ | * Close **valves 8 and 24** | ||
+ | |||
+ | * Open **valves 6 and 22** | ||
+ | |||
+ | * Enter vault and close main valves on gas bottles: | ||