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venting_pumping_intermediate_image_box [2018/12/18 11:18] pereira [Vent Intermediate-image chamber] |
venting_pumping_intermediate_image_box [2024/01/11 12:39] noji [Evacuating the Chamber] |
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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 (II-GHS) was designed to perform these tasks safely. The system is schematically illustrated in the figure below. It shows the status of the valves | + | * [[#General information]] |
+ | * [[#Emptying Detectors]] | ||
+ | * [[#Filling and Running Detectors]] | ||
+ | * [[# | ||
+ | ===== 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 II-GHS equipment (valves, | ||
- | {{:wiki:ghsiippacs.png?1000|Gas Handling System of S800 Intermediate Image}} | + | {{:wiki:IIGHShardware.jpeg|Gas Handling System of S800 Intermediate Image}} |
- | The II-GHS equipment (valves, flow-meter, pipes, isobutane gas bottle. etc.) are located | + | 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. |
- | {{:wiki:IIGHShardware.jpg?600|Gas Handling System of S800 Intermediate Image}} | + | {{:wiki:ii-ppac-ghs-css.png|}} |
+ | The layout of the II-GHS is shown below. | ||
+ | {{: | ||
+ | The operational states of the II-GHS are shown in the diagram below. | ||
+ | {{: | ||
+ | ===== Emptying Detectors ===== | ||
+ | - Set “PPAC Setpoint” to 0 Torr. | ||
+ | - Click **EMPTY** on the “GHS_II-PPAC_Main” page to open valves #3 and #4 which will allow for pumping out the gas quickly. | ||
+ | - When “PPAC Pressure” reads < 0.1 Torr, turn off IG and click **MAN** and then **AUTO**. This will open valve #6 to release the remaining gas into the diagnostics box. | ||
+ | - Monitor D2340 pumping station and ensure the TMP stays on and TGV remains open. If not, contact the Vacuum Operation group. | ||
+ | - Valves #1-5 should be closed and valve #6 should remain open. From this state click **VENT** and then **PUMP** to enter pump mode and leave the system in this state until it is ready to be filled. | ||
+ | ===== Venting the Chamber ===== | ||
+ | From the S800 Main Vacuum page, go to the Intermediate Image - RBT_BTS32 D2430 Pumping Station page, and ensure | ||
+ | * that the PPACs have been unbiased, | ||
+ | * that this pumping station has been isolated by having the gate valves **D2426 BGV** and **D2436 BGV** closed, and that the IG has been turned off, and | ||
+ | * that the turbo pump gate valve **TVG** is closed. | ||
- | ===== Vent Intermediate-image chamber ===== | + | The TMP can be turned off at this time. |
- | Requirements: | + | |
- | * Verify that PPACs are in automatic mode with gas removed (**S3_Gas_Handling**) | + | To vent the chamber: |
- | * The "GH System Status box should read "Auto Mode Gas Removed" | + | - Put the GHS in vent mode by clicking **VENT** (valves #5 and #6 are open), |
- | * 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" | + | |
- | | + | |
- | * Check that the detectors are unbiased by opening the [[HV bias|HV GUI]] | + | - open **Vent** valve to start venting. |
- | * Notify the system of the bias-off state by selecting | + | |
- | | + | |
- | * Isolate chamber by closing gate valves | + | |
- | * [[Vacuum control|Turn off]] ion gauge **I213IG** | + | |
- | * Check box " | + | |
- | {{: | + | |
- | * In order to begin venting process, select box "VENT STATUS" | + | |
- | * Box "VENT STATUS" | + | |
- | | + | |
- | * When **I215PG** reads atmospheric pressure, select the box "VENT STATUS" | + | |
- | * The status in the box "VENT STATUS" | + | The PPAC pressure S800_GHS: |
- | * You can now open the chamber | + | RBT_BTS32: |
+ | ===== Evacuating | ||
+ | Ensure | ||
+ | * that the chamber is closed | ||
+ | * that the pressure-relief mechanism (on the north side of the chamber, see picture below) is sealing (if not, adjust the flange back in place) | ||
+ | {{ : | ||
+ | * that the manual valve (see picture below) is closed. | ||
+ | {{ : | ||
- | ===== Pumping Intermediate-image | + | To evacuate the chamber: |
- | Requirements: PanelMate files **S3_Gas_Handling** and **S800Vac** | + | |
- | | + | |
- | * Verify that PPACs are not biased by opening the [[HV bias|HV GUI]] | + | |
- | | + | |
- | + | | |
- | * Insert PPACs/turn on light (Diagnostic Drives PanelMate) | + | - now open the manual valve slowly while watching the local display of the Pirani gauge. Open slowly such that the pressure |
- | * Open **S800Vac** and go to page 03 (" | + | - On the CSS window, after D2430 turns to yellow indicating that the section is in "POOR VACUUM", |
- | | + | |
- | | + | |
- | | + | - Be sure to go back to S3 and close the manual valve. |
- | * Verify PPACs changing shape through sighting | + | ===== Filling and Running Detectors ===== |
- | * Pump to about 100 Torr before | + | - If in Vent Mode, click **PUMP** then click **RUN** to enter Run Mode. |
- | | + | |
- | * When the pressure in **I215PG** is below 200 mTorr, | + | - Plot and monitor IG_D2430: |
- | * **I214RV** will be closed | + | - 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 |
- | * **I214FV** will be opened | + | - PPAC pressure |
- | | + | |
- | | + | |
- | | + | |
- | * 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 | + | |
+ | ===== Troubleshooting ===== | ||
+ | - If any issues are encountered during filling, running, or emptying, contact the Vacuum Operation group for assistance. |