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venting_pumping_intermediate_image_box [2018/12/19 11:07] pereira [Pumping Intermediate-image chamber] |
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 Intermediate-image delay PPAC]] | + | * [[#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: | + | |
- | * Verify that PPACs are in automatic mode with gas removed (**S3_Gas_Handling**) | + | {{:wiki:IIGHShardware.jpeg|Gas Handling System of S800 Intermediate Image}} |
- | * 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 " | + | |
- | {{:wiki:iis800vac_pumped.jpg?500|S800vac Panel Mate}}. | + | |
- | * 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" | + | 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. |
- | * You can now open the chamber | + | |
+ | {{: | ||
- | ===== Pumping Intermediate-image chamber ===== | + | The layout |
- | 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 | + | |
- | * 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). | + | {{:wiki:ii-ppac-ghs-layout.png|}} |
- | * 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, which is helpful to control rate of pumping. | + | |
- | * 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 | + | |
+ | 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 begin pumping out the gas quickly. | ||
+ | - When “PPAC Pressure” reads < 0.1 Torr, click **MAN** and then **AUTO**. This will 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 PUMP to enter pump mode and leave the system in this state until it is ready to be filled. | ||
+ | * Jorge noted on 2/12/2023 that this step did not work; he reported that when he clicked **PUMP** nothing happened. Instead, he had to “manually” enter the PV name associated with this command and changed from 0 to 1. He speculated that this was most likely due to a CS Studio problem. | ||
- | ===== Filling Intermediate-image delay PPAC ===== | + | ===== 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. |