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installation_fp_sci [2017/06/21 15:31] pereira [Pumping focal-plane chamber] |
installation_fp_sci [2019/07/01 09:28] pereira [Vent focal-plane chamber] |
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====== Installation of focal-plane scintillator ====== | ====== Installation of focal-plane scintillator ====== | ||
+ | In June 2019, a new Turbo Pump with magnetically-levitating bearings (Leybold MAG 2200iP) was installed in the S800 focal-plane chamber. This pump has a dry-N line connected to it that is purging continuously the bearings. This creates an extra pressure in the foreline, which must be pumping down continuously. Therefore, it is critical turn off the turbo pump whenever the foreline valve needs to be closed. | ||
+ | |||
+ | Instructions on how to vent/ | ||
===== 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, and ensure that I265GV (gate valve separating FP box from rest of beam line) is closed. | + | * Open PanelMate and select **S800vac** file in directory \\exp\files\control\ncsdata\General\Qt\Templates, and go to page 07 (see figure below) |
- | * Click on the **VENT STATUS** window and begin the venting procedure. The **VENT VALVE I260VV** window will turn red and display " | + | {{: |
+ | * 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) | * 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) | ||
{{: | {{: | ||
+ | * Make sure that pressure inside the CRDCs and IC detectors (LabView) increase at the same rate than the pressure in the chamber. Otherwise, stop the venting process inmediately. | ||
* 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 " | ||
+ | * Meanwhile, turn the turbo pump off using PanelMate **S800vac**: | ||
+ | * When the Turbo pump is fully stopped, switch off the chiller located near the S800 electronics rack | ||
* When the chamber is fully vented, select **VENT STATUS** and click **STOP VENTING PROCEDURE**. This will automatically close the vent valve **I260VV** | * 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 | * Close the manual vent valve | ||
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* 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) | * 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 " | * 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 pump will start pumping. | * 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). | * 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**. | * 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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