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installation_fp_sci [2015/05/04 13:02] pereira [Installation of FP scintillator] |
installation_fp_sci [2018/04/09 12:10] pereira [Vent focal-plane chamber] |
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====== Installation of focal-plane scintillator ====== | ====== Installation of focal-plane scintillator ====== | ||
- | ==== Vent focal-plane chamber ==== | + | ===== Vent focal-plane chamber |
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- | | + | * Open PanelMate and select **S800vac** file in directory \\exp\files\control\ncsdata\General\Qt\Templates. Go to page 07, and ensure that I265GV (gate valve separating FP box from rest of beam line) is closed. |
- | | + | * Click on the **VENT STATUS** window and begin the venting procedure. The **VENT VALVE I260VV** window will turn red and display " |
+ | | ||
+ | {{: | ||
+ | | ||
+ | * When the chamber is fully vented, select **VENT STATUS** and click **STOP VENTING PROCEDURE**. This will automatically close the vent valve **I260VV** | ||
+ | * Close the manual vent valve | ||
- | ==== Open focal-plane chamber ==== | + | ===== Open focal-plane chamber |
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- | ==== Closing focal-plane chamber | + | ===== Installing FP scintillator ===== |
- | - Turn the switch to move the chamber to position " | + | |
- | - 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 | + | |
- | - In order to pumpdown the chamber, make sure that the manual vent valve is closed | + | |
- | - Start the manual pump to get a pressure below 50 mtorr {{: | + | |
- | - | + | |
- | - | + | |
- | - The figure below shows the FP chamber open, with the " | + | |
- | - Unplug the bases of the up and down phototubes. The platic tie holding the cable of the up phototube to the chamber needs to be cut {{: | + | |
- | - Using an allen wrench, unscrew the two bolts attaching the scintillator frame to the base of the chamber {{: | + | |
- | - Climb to the chamber and pull the scintillator frame up. Once unplugged, handle it to a second person {{: | + | |
- | - With the help of a second person, hold the new scintillator by its frame and place it in the right spot. A second person should be ready to screw the frame to the base of the chamber | + | |
- | - Connect the bases of the up and down phototubes. The later is quite difficult because one cannot see the pins | + | |
- | - Using a plastic tie, attach the cable of the up phototube to the scintillator frame | + | |
- | - | + | |
+ | * The figure below shows the FP chamber open, with the " | ||
+ | * Unplug the bases of the up and down phototubes. The platic tie holding the cable of the up phototube to the chamber needs to be cut {{: | ||
+ | * Using an allen wrench, unscrew the two bolts attaching the scintillator frame to the base of the chamber {{: | ||
+ | * Climb to the chamber and pull the scintillator frame up. Once unplugged, handle it to a second person {{: | ||
+ | * With the help of a second person, hold the new scintillator by its frame and place it in the right spot. A second person should be ready to screw the frame to the base of the chamber | ||
+ | * Connect the bases of the up and down phototubes. The later is quite difficult because one cannot see the pins | ||
+ | * Using a plastic tie, attach the cable of the up phototube to the scintillator frame | ||
- | he first step to do is unplugging the up and down bases of the phototubes | ||
- | In order to remove the " | ||
- | Click Vent status [start pumpdown] | + | ===== Closing focal-plane chamber ===== |
+ | * Turn the switch to move the chamber to position " | ||
+ | * Check the display indicating the weight lift by the hydraulic system. When the chamber is close, the weight displayed will increase drastically due to the resistance experienced by the hydraulic system. At that point, stop immediately the lifting switch (otherwise, a weight-limit set point might be reached, disabling the hydraulic system) | ||
+ | * Turn the knob to close the clamps | ||
+ | * Inspect the clamps and chamber flange (no gaps) to ensure that the chamber is properly sealed | ||
+ | * 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 | ||
+ | |||
+ | ===== Pumping focal-plane chamber ===== | ||
+ | * Make sure that the pressure-relief valve and the manual vent valve (see above) are closed. | ||
+ | * Make sure that manual valve of the mechanical pump is opened (the valve **I260RV** will be automatically opened | ||
+ | * Open PanelMate **S800vac** and go to page 07. Make sure that the venting valve **I260VV** is closed (see last step of the [[#Vent focal-plane chamber|venting process]] described above) | ||
+ | * Select window **PUMPDOWN STATUS** and click on button **START PUMPDOWN**. The **PUMPDOWN STATUS** and **VENT STATUS** windows should display " | ||
+ | * After the rough valve **I260RV** is automatically open, the mechanical pump will start pumping. | ||
+ | * The pressures in the mechanical pump (from **I259PG**) and beam chamber (from **I261PG**) will jump momentarily to very high values. They should go down slowly after few seconds (otherwise, the chamber is not properly closed). | ||
+ | * When pressure in the chamber (from **I261PG**) gets below 100 mTorr (at least 30 min), **I260RV** will close. Foreline valve **I260FV** will open followed by the turbo gate valve **I260GV**. | ||
+ | * Wait for few hours until vacuum is good. You can then turn on the ion gauge **I264IG** | ||
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