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venting_pumping_intermediate_image_box [2017/06/12 12:32] pereira [Venting/pumping Intermediate Image box] |
venting_pumping_intermediate_image_box [2018/12/19 11:22] pereira [Filling Intermediate-image delay PPAC] |
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- | ===== Venting/ | + | ====== Venting/ |
- | The procedures to vent/pump the S800 Intermediate | + | * [[#General information]] |
+ | * [[# | ||
+ | * [[#Pumping Intermediate-image chamber]] | ||
+ | * [[#Filling Intermediate-image delay PPAC]] | ||
- | {{:wiki:fp-venting-valve-Daniel.jpg? | + | ===== General information ===== |
+ | The procedures to vent/pump the S800 Intermediate Image box, and/or filling the PPAC detectors with gas must be done carefully to ensure that the PPACs are not damaged. For instance, before | ||
- | ==== Vent focal-plane chamber ==== | + | {{:wiki:ghsiippacs.png?1000|Gas Handling System of S800 Intermediate Image}} |
- | * 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. 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 ~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 " | + | |
+ | The II-GHS equipment (valves, flow-meter, pipes, isobutane gas bottle. etc.) are located on the west balcony of the top level in the S3 vault (see figure below): | ||
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+ | ===== Vent Intermediate-image chamber ===== | ||
+ | Requirements: | ||
+ | |||
+ | * Verify that PPACs are in automatic mode with gas removed (**S3_Gas_Handling**) | ||
+ | * The "GH System Status box should read "Auto Mode Gas Removed" | ||
+ | * If gas is removed but the system is not in the automatic mode, consult the Beam Physicists or Device Physicist. NOTE: the only valves that should be open in **S3_Gas_Handling** are the "Det Bypass" | ||
+ | * Verify that PPACs are not biased: | ||
+ | * Check that the detectors are unbiased by opening the [[HV bias|HV GUI]] | ||
+ | * Notify the system of the bias-off state by selecting the " | ||
+ | * Open **S800Vac** and go to page 03 (" | ||
+ | * Isolate chamber by closing gate valves **I212GV** and **I215GV** | ||
+ | * [[Vacuum control|Turn off]] ion gauge **I213IG** | ||
+ | * Check box " | ||
+ | {{: | ||
+ | * In order to begin venting process, select box "VENT STATUS" | ||
+ | * Box "VENT STATUS" | ||
+ | * Turbo gate valve **I214GV** will be automatically closed and pressure in chamber will start rising (as seen in **I215PG**) {{: | ||
+ | * When **I215PG** reads atmospheric pressure, select the box "VENT STATUS" | ||
+ | |||
+ | * The status in the box "VENT STATUS" | ||
+ | * You can now open the chamber | ||
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+ | |||
+ | ===== Pumping Intermediate-image chamber ===== | ||
+ | Requirements: | ||
+ | * Verify that Chamber is closed and pressure-relief valve (north side of the chamber) is properly closed (NOTE: sometimes, due to overpressure from dry N2 during the venting procedure, the O-ring in pressure-relief valve flange is moved out of place) | ||
+ | * Verify that PPACs are not biased by opening the [[HV bias|HV GUI]] | ||
+ | * IMPORTANT: Verify that manual roughing pump valve located near the intermediate-image chamber is closed{{: | ||
+ | |||
+ | * Insert PPACs/turn on light (Diagnostic Drives PanelMate) and verify condition through sight window on south side of the chamber (be careful no to bump the bullet camera). | ||
+ | * Open **S800Vac** and go to page 03 (" | ||
+ | * Check " | ||
+ | * Slowly crack manual roughing valve | ||
+ | * Start slow (< 1 Torr/sec). Chamber pressure is displayed in **I215PG** in **S800Vac** PanelMate. There is also a local display of the mechanical pump pressure on a Granville-Phillips 275 Mini-Convectron, | ||
+ | * Verify PPACs changing shape through sighting window. | ||
+ | * Pump to about 100 Torr before fully opening the roughing valve. | ||
+ | * Once roughing valve is fully open, retract PPACs and turn lights off. | ||
+ | * When the pressure in **I215PG** is below 200 mTorr, the Turbo Pump will start automatically through the following sequence: | ||
+ | * **I214RV** will be closed | ||
+ | * **I214FV** will be opened | ||
+ | * **I214GV** will be opened | ||
+ | * When the pressure ready by **I215PG** is few mTorr, you can turn on the ion gauge **I213IG**. Good vacuum will take ~1-2 hours. | ||
+ | * NOTE: it sometimes happens that the foreline pressure rises above the trip point for the Turbo Pump (e.g. if the pumpdown timer expires before pressure is below 300 mTorr, or there is too much back-up pressure from the chamber when the foreline valve opens). In this situation, you will see that: (1) the turbo pump will stop, (2) the turbo gate valve **I214GV** will be closed, (3) the foreline valve **I214FV** will be closed and the corresponding PanelMate box will turn red and display an error message " | ||
+ | * Select box labeled " | ||
+ | * Select box labeled "TURBO PUMP INTERMEDIATE IMAGE BOX I214TP" | ||
+ | * Turbo pump will start ramping speed. When the TP reaches 40000 RPM, the **I214GV** will open automatically. | ||
+ | * When foreline vacuum gets below 2 Torr, you can select " | ||
+ | * (Note: sometimes it is necessary to repeat this operation a couple of times). | ||
+ | * At the end of the procedure, close the manual roughing pump valve | ||
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+ | ===== Filling Intermediate-image delay PPAC ===== | ||
+ | Requirements: | ||
+ | |||
+ | * Verify that PPACs are not biased: | ||
+ | * Check that the detectors are unbiased by opening the [[HV bias|HV GUI]] | ||
+ | * Notify the system of the bias-off state by selecting the " | ||
+ | * Verify that PPACs are in automatic mode with gas removed (**S3_Gas_Handling**) | ||
+ | * The "GH System Status box should read "Auto Mode Gas Removed" | ||
+ | * If gas is removed but the system is not in the automatic mode, consult the Beam Physicists or Device Physicist. This typically requires to verify that the system is in a controlled status. In particular, the " | ||
+ | * Confirm that PanelMate box " | ||
+ | * PanelMate box "Gas Flow Control" | ||
+ | * | ||
+ | * | ||
+ | * Open **S800Vac** and go to page 03 (" | ||
+ | * Isolate chamber by closing gate valves **I212GV** and **I215GV** | ||
+ | * [[Vacuum control|Turn off]] ion gauge **I213IG** | ||
+ | * Check box " |