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installation_fp_sci [2015/05/04 13:06] pereira [Closing focal-plane chamber] |
installation_fp_sci [2019/07/01 09:02] pereira [Vent focal-plane chamber] |
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====== Installation of focal-plane scintillator ====== | ====== Installation of focal-plane scintillator ====== | ||
- | ==== Vent focal-plane chamber ==== | + | In June 2019, a new Turbo Pump with magnetically-levitating bearings |
- | - Open the [[hv_bias|HV Remote Control]] GUI and ensure that the focal-plane detectors are unbiased | + | |
- | - Open the [[gas_handling_system# | + | |
- | | + | |
- | - Open PanelMate and select **S800vac** file in directory \\exp\files\control\ncsdata\General\Qt\Templates. Go to page 07, click on the **VENT STATUS** window and begin the venting procedure. The **VENT VALVE I260VV** window will turn red and display " | + | |
- | - Gently open the manual venting valve until the pressure displayed in the Pirani Gauge (see figure below) increases by ~4 torr/ | + | |
- | - Wait until the chamber is vented (few hours). The **I261PG** Pirani Gauge should read atmospheric pressure. The window **VENT STATUS** in PanelMate should display "VENT VALVE OPEN". The window **PUMPDOWN STATUS** should display " | + | |
- | ==== Open focal-plane chamber ==== | + | Instructions on how to vent/ |
+ | ===== Vent focal-plane chamber ===== | ||
+ | * Open the [[hv_bias|HV Remote Control]] GUI and ensure that the focal-plane detectors are unbiased | ||
+ | * Open the [[gas_handling_system# | ||
+ | * Ensure that the manual venting valve located on the south side of the chamber is closed (see figures below) | ||
+ | * Ensure that the FP ion gauge (I264IG) is off (see details [[vacuum_control|here]]) | ||
+ | * Open PanelMate and select **S800vac** file in directory \\exp\files\control\ncsdata\General\Qt\Templates, | ||
+ | * Close 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 " | ||
+ | * Gently open the manual venting valve until the pressure displayed in the Pirani Gauge (see figure below) increases by ~1 torr every 15 seconds (see figures below) | ||
+ | {{: | ||
+ | * Wait until the chamber is vented (few hours). The **I261PG** Pirani Gauge should read slightly above atmospheric pressure (due to the dry N2 flow pumped to the chamber). The window **VENT STATUS** in PanelMate should display "VENT VALVE OPEN". The window **PUMPDOWN STATUS** should display " | ||
+ | * Meanwhile, turn the turbo pump off using PanelMate and select **S800vac** | ||
+ | * 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 |
- | - Unlock the padlock protecting the power brakers of the switch controls to open the chamber, and press the **START** button {{: | + | |
- | - Turn the switch to open the clamps holding the FP chamber. The weight held by the hydraulic piston will increase {{: | + | |
- | - Turn on the switch to activate the motor opening the chamber. It takes about 10 minutes to get the chamber totally opened {{: | + | |
+ | * 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 " | ||
+ | * Unlock the padlock protecting the power brakers of the switch controls to open the chamber, and press the **START** button {{: | ||
+ | * Turn the switch to open the clamps holding the FP chamber. The weight held by the hydraulic piston will increase {{: | ||
+ | * Turn on the switch to activate the motor opening the chamber. It takes about 10 minutes to get the chamber totally opened {{: | ||
- | ==== Installing FP scintillator ==== | ||
- | - The figure below shows the FP chamber open, with the " | + | ===== Installing |
- | - 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 | + | |
+ | * 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 | ||
- | ==== Closing focal-plane chamber ==== | + | |
- | | + | ===== Closing focal-plane chamber |
- | | + | |
- | | + | |
- | - In order to pumpdown the chamber, make sure that the manual vent valve is closed. | + | * Turn the knob to close the clamps |
- | - Close the manual | + | |
- | | + | * 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 | ||
+ | | ||
+ | * Select window **PUMPDOWN STATUS** and click on button **START PUMPDOWN**. The **PUMPDOWN STATUS** and **VENT STATUS** windows should display " | ||
+ | * The vent valve **I260VV** and foreline valve **I260FV** will be automatically closed | ||
+ | * After the rough valve **I260RV** is automatically open, the mechanical | ||
+ | * 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**. | ||
+ | | ||
+ |