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venting_pumping_intermediate_image_box [2017/06/12 14:19] pereira [Venting/pumping Intermediate Image box and filling PPACs with gas] |
venting_pumping_intermediate_image_box [2018/12/19 11:10] pereira [Filling Intermediate-image delay PPAC] |
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- | ===== Venting/ | + | ====== Venting/ |
- | 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 venting the chamber, we have to make sure that the PPACs are empty and equalized with respect to the vacuum in the chamber. In order to avoid errors, an automated gas handling system was designed to perform these tasks safety. The system is schematically illustrated in the figure below. It shows the status of the valves (red: closed, white: open) when the intermediate image chamber is under vacuum and the PPACs are filled with gas: | + | * [[#General information]] |
+ | * [[#Vent Intermediate-image chamber|Venting Intermediate-image chamber]] | ||
+ | * [[#Pumping Intermediate-image chamber]] | ||
+ | * [[#Filling Intermediate-image delay PPAC]] | ||
+ | |||
+ | ===== 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 venting the chamber, we have to make sure that the PPACs are empty and equalized with respect to the vacuum in the chamber. In order to avoid errors, an automated gas handling system | ||
{{: | {{: | ||
- | ==== Vent focal-plane chamber ==== | + | |
- | * Open the [[hv_bias|HV Remote Control]] GUI and ensure | + | 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): |
- | * Open the [[gas_handling_system# | + | |
- | * Ensure | + | {{: |
- | * Ensure that the FP ion gauge (I264IG) is off (see details [[vacuum_control|here]]) | + | |
- | * Open PanelMate and select | + | |
- | * Gently open the manual | + | |
- | {{:wiki:fp-pirani.jpg?350|FP chamber manual venting valve}} | + | |
- | * Wait until the chamber is vented | + | |
+ | |||
+ | |||
+ | ===== 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 | ||
+ | * Notify | ||
+ | * Open **S800Vac** and go to page 03 (" | ||
+ | | ||
+ | | ||
+ | | ||
+ | {{: | ||
+ | | ||
+ | | ||
+ | | ||
+ | * When **I215PG** reads atmospheric pressure, select the box "VENT STATUS" | ||
+ | |||
+ | * The status in the box "VENT STATUS" | ||
+ | * You can now open the chamber | ||
+ | |||
+ | |||
+ | ===== Pumping Intermediate-image chamber ===== | ||
+ | Requirements: | ||
+ | * Verify | ||
+ | * Verify that PPACs are not biased by opening the [[HV bias|HV GUI]] | ||
+ | * IMPORTANT: Verify that manual | ||
+ | |||
+ | * Insert PPACs/turn on light (Diagnostic Drives PanelMate) and verify condition through sight window on south side of the chamber | ||
+ | * Open **S800Vac** and go to page 03 (" | ||
+ | | ||
+ | * Slowly crack manual | ||
+ | * Start slow (< 1 Torr/sec). Chamber | ||
+ | * 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). | ||
+ | | ||
+ | |||
+ | |||
+ | |||
+ | |||
+ | ===== Filling Intermediate-image delay PPAC ===== | ||
+ | Requirements: | ||
+ | |||
+ | * Verify that PPACs are in automatic mode with gas removed (**S3_Gas_Handling**) | ||
+ | * The "GH System Status box should | ||
+ | * If gas is removed but the system is not in the automatic mode, consult the Beam Physicists or Device | ||