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installation_fp_sci [2017/03/06 12:31] pereira [Installing FP scintillator] |
installation_fp_sci [2017/06/13 12:10] pereira old revision restored (2017/06/13 12:06) |
==== Open focal-plane chamber ==== | ==== Open focal-plane chamber ==== |
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* After venting the FP chamber, the pressure inside the chamber is slightly above atmospheric due to the dry N2 pumped. Before opening the chamber, it is recommended to vent the extra N2 by "forcing" the chamber flange with e.g. a screwdriver {{:wiki:screwdriver-flange.jpg?350}} | * After venting the FP chamber, the pressure inside the chamber is slightly above atmospheric due to the dry N2 pumped. Before opening the chamber, it is recommended to vent the extra N2 by "forcing" the pressure-relief valve with e.g. a screwdriver {{:wiki:screwdriver-flange.jpg?350}} |
* Unlock the padlock protecting the power brakers of the switch controls to open the chamber, and press the **START** button {{:wiki:padlock-note.jpg?350|Padlock}} | * Unlock the padlock protecting the power brakers of the switch controls to open the chamber, and press the **START** button {{:wiki:padlock-note.jpg?350|Padlock}} |
* Turn the switch to open the clamps holding the FP chamber. The weight held by the hydraulic piston will increase {{:wiki:switch-clamps.jpg?250|Switch clamps}} {{:wiki:clamps.jpg?400|Clamps holding FP chamber}} {{:wiki:scale.jpg?350|Scale FP chamber}} | * Turn the switch to open the clamps holding the FP chamber. The weight held by the hydraulic piston will increase {{:wiki:switch-clamps.jpg?250|Switch clamps}} {{:wiki:clamps.jpg?400|Clamps holding FP chamber}} {{:wiki:scale.jpg?350|Scale FP chamber}} |
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==== Closing focal-plane chamber ==== | ==== Closing focal-plane chamber ==== |
- Turn the switch to move the chamber to position "UP", and keep it that way for about 10 minutes (the time it takes the chamber to be closed) | * Turn the switch to move the chamber to position "UP", and keep it that way for about 10 minutes (the time it takes the chamber to be closed) |
- When the chamber is almost close, turn the know to close the clamps | * When the chamber is almost close, turn the know to close the clamps |
- Before pumping the chamber down, make sure that the scintillator is properly connected. This can be done by biasing the detector and checking the signals, either from the scalers or with a scope. One should clearly see cosmic rays; if that is not the case, the phototubes are likely miss connected | * Before pumping the chamber down, make sure that the scintillator is properly connected. This can be done by biasing the detector and checking the signals, either from the scalers or with a scope. One should clearly see cosmic rays; if that is not the case, the phototubes are likely miss connected |
- In order to pumpdown the chamber, make sure that the manual vent valve is closed. Start manual pump to get a pressure below 50 mtorr {{:wiki:ManualValve-fp.jpg?350|Manual valve pump}} | |
- Close the manual pump; open PanelMate **S800vac** and go to page 07. Select window **PUMPDOWN STATUS** and click on button **START PUMPDOWN**. The **PUMPDOWN STATUS** and **VENT STATUS** windows should display "PUMPDOWN IN PROGRESS" | ==== Pumping focal-plane chamber ==== |
- Wait for some hours until vacuum is good | * Make sure that the pressure-relief valve (see above) is in place (closed). |
| * In order to pumpdown the chamber, make sure that the manual vent valve is closed. Start manual pump to get a pressure below 50 mtorr {{:wiki:ManualValve-fp.jpg?350|Manual valve pump}} |
| * Close the manual pump; open PanelMate **S800vac** and go to page 07. Select window **PUMPDOWN STATUS** and click on button **START PUMPDOWN**. The **PUMPDOWN STATUS** and **VENT STATUS** windows should display "PUMPDOWN IN PROGRESS" |
| * Wait for some hours until vacuum is good |