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venting_pumping_intermediate_image_box [2017/06/12 12:28] pereira created |
venting_pumping_intermediate_image_box [2024/01/11 11:01] noji [Venting the Chamber] |
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- | ===== Venting/ | + | ====== Venting/ |
+ | * [[#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, flow-meter, pipes, isobutane gas bottle. etc.) are located on the west balcony of the top level in the S3 vault (see figure below): | ||
- | ==== Vent focal-plane chamber ==== | + | {{:wiki:IIGHShardware.jpeg|Gas Handling System of S800 Intermediate Image}} |
- | * Open the [[hv_bias|HV Remote Control]] GUI and ensure that the focal-plane detectors are unbiased | + | |
- | * Open the [[gas_handling_system# | + | |
- | * Ensure that the manual venting valve located on the south side of the chamber is closed (see figures below) | + | |
- | * Ensure that the FP ion gauge (I264IG) is off (see details [[vacuum_control|here]]) | + | |
- | * Open PanelMate and select **S800vac** file in directory \\exp\files\control\ncsdata\General\Qt\Templates. Go to page 07, click on the **VENT STATUS** window and begin the venting procedure. The **VENT VALVE I260VV** window will turn red and display " | + | |
- | * Gently open the manual venting valve until the pressure displayed in the Pirani Gauge (see figure below) increases by ~1 torr every 15 seconds (see figures below) | + | |
- | {{: | + | |
- | * Wait until the chamber is vented (few hours). The **I261PG** Pirani Gauge should read slightly above atmospheric pressure (due to the dry N2 flow pumped to the chamber). The window **VENT STATUS** in PanelMate should display "VENT VALVE OPEN". The window **PUMPDOWN STATUS** should display " | + | |
+ | 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. | ||
+ | |||
+ | {{: | ||
+ | |||
+ | 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. | ||
+ | |||
+ | The TMP can be turned off at this time. | ||
+ | |||
+ | To vent the chamber: | ||
+ | - Put the GHS in vent mode by clicking **VENT** (valves #5 and #6 are open), | ||
+ | - monitor **RBT_BTS32: | ||
+ | - close **RV**, the valve to the roughing pump, and | ||
+ | - open **Vent** valve to start venting. | ||
+ | |||
+ | The PPAC pressure S800_GHS: | ||
+ | RBT_BTS32: | ||
+ | ===== 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. |