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preparation_for_tuning_the_s800 [2013/12/13 19:29] pereira created |
preparation_for_tuning_the_s800 [2013/12/13 20:53] pereira |
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====== Preparation for tuning ====== | ====== Preparation for tuning ====== | ||
- | * [[Software]] | + | * [[Software|Software overview]] |
- | * [[Electronics]] | + | * [[Electronics |
* [[Gas handling system]] | * [[Gas handling system]] | ||
* [[HV bias]] | * [[HV bias]] | ||
Line 7: | Line 7: | ||
* [[Turning magnets on/off]] | * [[Turning magnets on/off]] | ||
* [[Magnetic-rigidity setting]] | * [[Magnetic-rigidity setting]] | ||
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- | ELECTRONICS, | ||
- | data-U6 (south end) | ||
- | Electronic location: two racks that contain all the electronics and patch panels. | ||
- | Oscilloscope TEKSCOPE11 | ||
- | Use: S800 detector/ | ||
- | Location: | ||
- | NMR Oscilloscopes | ||
- | Use: NMR resonances display | ||
- | Location: upper two shelves on right electronics rack | ||
- | NIM bin | ||
- | Location: below NMR scopes in right electronics racks | ||
- | Use: Canberra HV supply for Object scintillator | ||
- | Upper patch panels (top of left rack) | ||
- | Cables 1-10: to object | ||
- | Cables 11-20: | ||
- | Cables 21-25: | ||
- | Cable 26 is missing | ||
- | Cable 27-50 should go to pivot point (mostly not connect in vault) | ||
- | Middle patch panel (top of left rack) | ||
- | Cables 51-70: | ||
- | SHV cables 1-2: to object | ||
- | SHV cables 6-10: should go to intermediate image box (apparently not connected in vault) | ||
- | SHV cables 11-20: | ||
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- | S800 FP (top level of S3 vault) | ||
- | Electronics location: | ||
- | Patch panels: | ||
- | SHV Cables 21-30: | ||
- | Cables 51-70: | ||
- | Cables 91-110: | ||
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- | Pivot point (bottom level of S3 vault) | ||
- | Electronics location: | ||
- | Patch panels | ||
- | Cables 75-110: | ||
- | Cables 70-80: | ||
- | Cables 81-90: | ||
- | Cables 91-110: | ||
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- | Intermediate Image (accessed via middle level of S3 vault) | ||
- | Electronics location: | ||
- | Patch panels (in electronics rack on top level of S3 vault) | ||
- | Cables 21-25: | ||
- | Cables 81-90: | ||
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- | Object position (access via middle level of S3 vault) | ||
- | Electronics location: | ||
- | Patch panels (mounted on object box support under object box) | ||
- | Cables 11-20: | ||
- | Cables 71-80: | ||
- | SHV cables 1-2: to Data-U6 | ||
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- | DETECTOR GAS HANDLING SYSTEM | ||
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- | General Information | ||
- | Required controls and monitoring | ||
- | LabView gas handling system application | ||
- | PanelMate S800vac.MT2 page 07: Focal Plane Detector | ||
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- | 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. | ||
- | 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. | ||
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- | LabView Control Program | ||
- | To start the gas handling system control application, | ||
- | A log file should be specified before operating the gas handling system | ||
- | A window automatically pops up asking for the name of the log file when the program starts | ||
- | Use the number of the current experiment (or “test”) as the name of the log file and save in file | ||
- | // | ||
- | 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 xxx) | ||
- | 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. | ||
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- | Figure 1: Gas Handling System LabView running remotelly in S800FP-PC | ||
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- | Preparation of Gas bottles | ||
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- | 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. | ||
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- | Filling Ion Chamber with Gas | ||
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- | 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 | ||
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- | Filling CRDC1 and CRDC2 with Gas | ||
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- | 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 | ||
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- | Removing Gas from Focal Plane Detectors | ||
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- | 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 | ||
- | Open valves 6 and 22 | ||
- | Enter vault and close main valves on gas bottles: | ||
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