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installation_fp_sci [2017/06/13 12:07]
pereira [Pumping focal-plane chamber]
installation_fp_sci [2017/06/22 11:58] (current)
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#​labview_control_program|Labview gas handling system]] and verify that there is no gas in the CRDCs and IC. Open valves **4** (IC supply), **5** (IC bypass), **6** (IC focal-plane bypass), **20** (CRDC supply), **21** (CRDC bypass), and **22** (CRDC focal-plane bypass). The rest of the valves should be closed   * Open the [[gas_handling_system#​labview_control_program|Labview gas handling system]] and verify that there is no gas in the CRDCs and IC. Open valves **4** (IC supply), **5** (IC bypass), **6** (IC focal-plane bypass), **20** (CRDC supply), **21** (CRDC bypass), and **22** (CRDC focal-plane bypass). The rest of the valves should be closed
   * Ensure that the manual venting valve located on the south side of the chamber is closed (see figures below) ​ {{:​wiki:​fp-venting-valve-Daniel.jpg?​350|FP chamber manual venting valve}} {{:​wiki:​fp-venting-valve.jpg?​350|FP chamber manual venting valve}}   * Ensure that the manual venting valve located on the south side of the chamber is closed (see figures below) ​ {{:​wiki:​fp-venting-valve-Daniel.jpg?​350|FP chamber manual venting valve}} {{:​wiki:​fp-venting-valve.jpg?​350|FP chamber manual venting valve}}
   * 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"​. The pressure should remain constant because the manual venting valve is still closed+  * 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 "​OPEN"​. The pressure should remain constant because the manual venting valve is still closed
   * 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) ​
 {{:​wiki:​fp-pirani.jpg?​350|FP chamber manual venting valve}} ​ {{:​wiki:​fp-pirani.jpg?​350|FP chamber manual venting valve}} ​
   * 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 "​PUMPDOWN STOPPED"​   * 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 "​PUMPDOWN STOPPED"​
 +  * 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 "​forcing"​ the pressure-relief valve  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}}
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-==== Installing FP scintillator ====+===== Installing FP scintillator ​=====
  
   * The figure below shows the FP chamber open, with the "​old"​ FP scintillator to be replaced by the new one {{:​wiki:​E1-view.jpg?​350|FP chamber opened}}   * The figure below shows the FP chamber open, with the "​old"​ FP scintillator to be replaced by the new one {{:​wiki:​E1-view.jpg?​350|FP chamber opened}}
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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+  * 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   * 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 ​closed.  +  * Make sure that the pressure-relief valve and the manual vent valve (see above) are closed. 
-  * Start manual pump to get a pressure below 50 mtorr  +  * Make sure that manual ​valve of the mechanical ​pump is opened (the valve **I260RV** will be automatically opened in the next step) {{:​wiki:​ManualValve-fp.jpg?​350|Manual valve pump}} 
-{{:​wiki:​ManualValve-fp.jpg?​350|Manual valve pump}} +  * 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) 
-  * 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"​ +  * 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+       * 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** 
 + 
installation_fp_sci.1497370070.txt.gz · Last modified: 2017/06/13 12:07 by pereira