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gas_handling_system [2013/12/13 21:05] pereira |
gas_handling_system [2013/12/13 21:38] pereira [LabView Control Program] |
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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 | * 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 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, 20, 21, and 22** |
- | * In the S3 vault | + | ==== In the S3 vault ==== |
* Ensure that the gas handling system roughing pump is running and has a good vacuum | * 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 pump sits on the floor under the focal plane behind the south support post | ||
Line 41: | Line 41: | ||
* 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< |
+ | ===== Filling Ion Chamber with Gas ===== | ||
- | Filling Ion Chamber with Gas | + | * Follow instructions under [[# |
- | 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. |
- | 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 | + | |
+ | * 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 | ||
- | Filling CRDC1 and CRDC2 with Gas | + | * Close **valve 6** |
- | Follow instructions under PREPARATIONS FOR FILLING DETECTORS WITH GAS above | + | * Open **valve 2**; the flow reading at MFC #1 should jump momentarily |
- | 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 | + | |
+ | * 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 | ||
- | Removing Gas from Focal Plane Detectors | + | * When the detector is filled, close **valve 5** |
- | 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 | + | ===== Filling CRDC1 and CRDC2 with Gas ===== |
- | 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) | + | * Follow instructions under [[# |
- | 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 | + | * 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. |
- | Isolate the gas supply by closing valves 2, 12, 17, 10, and 15 | + | |
- | Open valves 5 and 21 | + | * Confirm that the detector pressure as indicated by the display labeled P.T. #2 reads below a couple of Torr |
- | IMPORTANT: | + | * To zero this display: |
- | Empty Ion Chamber to a pressure at or below the pressure of the CRDCs | + | * Click on the **Slot 4 (PT2)** tab to access the details page for PT #2 |
- | Open valve 8 | + | * Click the **Zero Sensor** button |
- | Wait for the Ion Chamber pressure to reach or drop below the pressure in the CRDCs; this process will take several minutes | + | * Click the **Valves** tab at the top of the LabView window to return to the overview display of the gas handling system |
- | Finish emptying both detectors | + | |
- | Open valve 25 | + | * Close **valve 22** |
- | 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 | + | * Open **valves 10 and 15** |
- | Close valves 9 and 25 | + | |
- | Close valves 8 and 24 | + | * Open **valve 12**; the flow reading at MFC #2 should jump momentarily |
- | Open valves 6 and 22 | + | |
- | Enter vault and close main valves on gas bottles: | + | * 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: | ||