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venting_pumping_intermediate_image_box [2019/02/13 09:40] pereira [Removing gas from Intermediate-image delay PPAC] |
venting_pumping_intermediate_image_box [2024/01/12 09:37] noji [Filling and Running Detectors] |
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- | ====== Venting/ | + | ====== Venting/ |
* [[#General information]] | * [[#General information]] | ||
- | * [[#Vent Intermediate-image chamber|Venting | + | * [[#Emptying Detectors]] |
- | * [[#Pumping Intermediate-image chamber]] | + | * [[#Venting |
- | * [[#Filling/Removing gas in Intermediate-image delay PPAC]] | + | * [[#Evacuating the Chamber]] |
+ | * [[# | ||
+ | * [[# | ||
===== 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**) | + | |
- | * 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 | + | |
+ | {{: | ||
- | ===== Pumping Intermediate-image chamber ===== | + | 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: | + | |
- | * Verify that Chamber | + | |
- | * 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-css.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 layout of the II-GHS is shown below. | ||
+ | {{: | ||
+ | The operational states of the II-GHS are shown in the diagram below. | ||
- | ===== Filling/ | + | {{:wiki:ii-ppac-ghs-operationalstates.png|}} |
- | {{: | + | ===== Emptying Detectors ===== |
+ | - Double check that the detectors have been unbiased. | ||
+ | - 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 ===== | ||
- | Requirements: | + | From the S800 Main Vacuum page, go to the Intermediate Image - RBT_BTS32 D2430 Pumping Station page, and ensure |
+ | | ||
+ | | ||
+ | * that the turbo pump gate valve **TVG** is closed. | ||
- | ==== Filling Intermediate-image delay PPAC with gas ==== | + | The TMP can be turned off at this time. |
- | * 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 ion gauge I213IG is off | + | |
- | * 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 | + | |
+ | To vent the chamber: | ||
+ | - Let the Control Room and the Vacuum Operation Group be aware as EXP alarms may occur, | ||
+ | - put the GHS in vent mode by clicking **VENT** (valves #5 and #6 are open), | ||
+ | - monitor **RBT_BTS32: | ||
+ | - ensure that **RV**, the valve to the roughing pump, is closed, and | ||
+ | - open **Vent** valve to start venting. | ||
+ | The PPAC pressure S800_GHS: | ||
+ | RBT_BTS32: | ||
+ | ===== Evacuating the Chamber ===== | ||
+ | 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. | ||
+ | {{ : | ||
- | ==== Removing gas from Intermediate-image delay PPAC ==== | + | To evacuate the chamber: |
- | | + | |
- | * Check that the detectors are unbiased by opening the [[HV bias|HV GUI]] | + | - put the GHS in pump mode by clicking |
- | * Notify the system of the bias-off state by selecting | + | |
- | * Verify that PPACs are in automatic mode with gas flowing (**S3_Gas_Handling**) | + | - open **RV**. |
- | * The "GH System Status box should | + | - A message window, which reads, |
- | * If gas is flowing but the system | + | - now open the manual valve slowly while watching the local display of the Pirani gauge. Open slowly such that the pressure reading |
- | * I214 Gas Sup V1 (open) | + | |
- | | + | - Turn on TMP, and wait until it reaches the normal rotation |
- | | + | - Open **TGV**. |
- | | + | |
- | | + | ===== Filling |
- | * Chmbr Bypass | + | - If in Vent Mode, click **PUMP** then click **RUN** to enter Run Mode. The valves |
- | * I214V_NCL (enabled) | + | - If in Pump Mode, click **RUN** to enter Run Mode. |
- | | + | |
- | * Valves V1 (I214 Gas Sup) and I214V_NCL will close | + | - 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. |
- | * Valves V3 (Flow Bypass) | + | - PPAC pressure should stabilize after ~1 min. HV may now be turned on to operate the PPACs. |
- | * I214CM Press Rdg will gradually decrease to zero | + | |
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- | * Valve V3 (Flow Bypass) | + | |
- | * Valve V6 (Chamber Bypass) will open | + | |
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- | * Close the gas bottle valve (sitting near the gas handling | + | |
+ | ===== Troubleshooting ===== | ||
+ | - If any issues are encountered during filling, running, or emptying, contact the Vacuum Operation group for assistance. |