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installation_fp_sci [2017/06/13 12:07] pereira [Pumping focal-plane chamber] |
installation_fp_sci [2017/06/20 17:27] pereira [Pumping 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 |
* Open the [[hv_bias|HV Remote Control]] GUI and ensure that the focal-plane detectors are unbiased | * Open the [[hv_bias|HV Remote Control]] GUI and ensure that the focal-plane detectors are unbiased | ||
* Open the [[gas_handling_system# | * 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 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]]) | * 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. 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 " | + | * 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 " | ||
* 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) | * 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 " | * 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 " | ||
+ | * 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 |
* 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 " | * 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 " | ||
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- | ==== Installing FP scintillator ==== | + | ===== Installing FP scintillator |
* The figure below shows the FP chamber open, with the " | * The figure below shows the FP chamber open, with the " | ||
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- | ==== Closing focal-plane chamber ==== | + | ===== Closing focal-plane chamber |
* Turn the switch to move the chamber to position " | * Turn the switch to move the chamber to position " | ||
- | * When the chamber is almost | + | * Check the display indicating the weight lift by 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 | * 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 ==== | + | ===== Pumping focal-plane chamber |
- | * In order to pumpdown the chamber, make sure that the manual vent valve is closed and the pressure-relief valve is properly | + | * Make sure that the pressure-relief valve and the manual vent valve (see above) are closed. |
- | * 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 " | + | * Make sure that manual |
+ | * 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 " | ||
+ | * The pressures in the mechanical pump (from **I259PG**) and beam chamber (from **I261PG**) will jump momentarily to very high values. They should go down after few seconds | ||
* Wait for some hours until vacuum is good | * Wait for some hours until vacuum is good | ||
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