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venting_pumping_intermediate_image_box [2018/12/20 15:12] pereira [Filling/Removing gas in Intermediate-image delay PPAC] |
venting_pumping_intermediate_image_box [2024/01/11 09:53] noji [General information] |
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- | ====== Venting/ | + | ====== Venting/ |
* [[#General information]] | * [[#General information]] | ||
- | * [[#Vent Intermediate-image chamber|Venting Intermediate-image chamber]] | + | * [[#Emptying Detectors]] |
- | * [[#Pumping Intermediate-image chamber]] | + | * [[#Filling and Running Detectors]] |
- | * [[#Filling/ | + | * [[#Troubleshooting]] |
===== General information ===== | ===== 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 (II-GHS) was designed to perform these tasks safely. | + | 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 (II-GHS) was designed to perform these tasks safely. 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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- | 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: | + | |
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- | * 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" | + | |
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- | * 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{{: | + | |
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- | * 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/ | + | {{: |
- | {{: | + | The GHS is operated remotely through CS studio. Its page can be found on the EXP network through FRIB EXP Main → S800 → GHS Pages (Secondary Pages) → Intermediate Image PPAC and is shown below. |
- | Requirements: PanelMate files **S3_Gas_Handling** and **S800Vac** | + | {{:wiki: |
- | ==== Filling Intermediate-image delay PPAC with gas ==== | + | The layout |
- | * Verify that PPACs are not biased: | + | |
- | * Check that the detectors are unbiased by opening the [[HV bias|HV GUI]] | + | |
- | * Notify the system | + | |
- | * Verify that ion gauge I213IG | + | |
- | * 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 " | + | |
- | * Open the gas bottle valve (sitting near the gas handling system) | + | |
- | * PanelMate box "Gas Flow Control" | + | |
- | * Valve V2 (Gas lin pmp out) will be opened and I214V_NCL will change from closed to " | + | |
- | * Valves V3 (Flow Bypass) and V4 (Det Return) will open | + | |
- | * Valve V1 (Gas supply) will open, and V2, V3, and V6 (Chamber Bypass) will close | + | |
- | * GH System status should indicate "Gas Flowing" | + | |
- | * I214CM Press Rdg will gradually increase to the set value | + | |
- | * When the detector is filled, valve V5 (Det Bypass) will close | + | |
- | * GH System status will indicate "Flow Estab." | + | |
- | * I214BON_CONFIM will change to "PPAC BIAS ASSUMED ON" | + | |
- | * The valves status will be: V1 (open), V2 (closed), V3 (closed), V4 (open), V5 (closed), V6 (closed, I214V_NCL (enabled) | + | |
- | * You can now turn on the detectors | + | |
+ | {{: | ||
+ | The operational states of the II-GHS are shown in the diagram below. | ||
+ | {{: | ||
- | ==== Removing gas from Intermediate-image delay PPAC ==== | + | ===== Emptying Detectors ===== |
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- | * Check that the detectors are unbiased by opening | + | - Click **EMPTY** on the “GHS_II-PPAC_Main” page to begin pumping out the gas quickly. |
- | * Notify the system of the bias-off state by selecting the " | + | - When “PPAC Pressure” reads < 0.1 Torr, click **MAN** and then **AUTO**. This will release |
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- | * The "GH System Status box should read "Auto Gas Flow Estab" | + | |
- | * If gas is flowing 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, | + | * Jorge noted on 2/12/2023 that this step did not work; he reported that when he clicked |
- | * I214 Gas Sup V1 (open) | + | |
- | * Gas Lin Pmp out V2 (closed) | + | |
- | * Flow Bypass V3 (closed) | + | |
- | * Det Return V4 (open) | + | |
- | * Det Bypass V5 (closed) | + | |
- | * Chmbr Bypass (closed) | + | |
- | * I1214V_NCL (enabled) | + | |
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- | * Valves V1 (I214 Gas Sup) and I214V_NCL will close | + | |
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- | * I214CM Press Rdg will gradually decrease | + | |
- | * GH System status should indicate "Gas Removal" | + | |
- | * When the gas is removed from the detector | + | |
- | * Valve V3 (Flow Bypass) and 4 (Det return) will close | + | |
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+ | ===== Venting the Chamber ===== | ||
+ | ===== Evacuating the Chamber ===== | ||
+ | ===== Filling and Running Detectors ===== | ||
+ | - If in Vent Mode, click **PUMP** then click **RUN** to enter Run Mode. | ||
+ | - If in Pump Mode, click **RUN** to enter Run Mode. | ||
+ | - Plot and monitor IG_D2430: | ||
+ | - Step up “PPAC Setpoint” by 1 Torr from 0 to 6 Torr. Allow the “PPAC Pressure” to stabilize for 15 seconds at each step. This should be a quick process but **DO NOT** simply set the “PPAC Setpoint” to 6 Torr as the gas flow could overwhelm the system. | ||
+ | - PPAC pressure should stabilize after ~1 min. HV may now be turned on to operate the PPACs. | ||
+ | ===== Troubleshooting ===== | ||
+ | - If any issues are encountered during filling, running, or emptying, contact the Vacuum Operation group for assistance. |