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--- venting_pumping_intermediate_image_box [2017/06/12 12:36]
pereira [Venting/pumping Intermediate Image box]
+++ venting_pumping_intermediate_image_box [2023/02/13 10:44]
noji Updated descriptions about the II-GHS based upon "S800 Intermediate Image PPAC Gas Handling System Operation Manual" (v4) provided to us on 2/8/2023 by B. Ewert.
@@ Line 1: / Line 1: @@
-===== Venting/pumping Intermediate Image box and filling PPACs with gas =====
+====== Venting/pumping Intermediate Image box and filling PPACs with gas ======
-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 was designed to perform these tasks safety. The system is schematically illustrated in the figure below:
+  * [[#General information]]
+  * [[#Vent Intermediate-image chamber|Venting Intermediate-image chamber]]
+  * [[#Pumping Intermediate-image chamber]]
+  * [[#Filling/Removing gas in Intermediate-image delay PPAC]]
-{{:wiki:ghsiippacs.png?1000|Gas Handling System of S800 Intermediate Image}}
+===== General information =====
-==== Vent focal-plane chamber ====
+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):
-  * Open the [[hv_bias|HV Remote Control]] GUI and ensure that the focal-plane detectors are unbiased
-  * Open the [[gas_handling_system#labview_control_program|Labview gas handling system]] and verify that there is no gas in the CRDCs and IC. Open valves **4** (IC supply), **5** (IC bypass), **6** (IC focal-plane bypass), **20** (CRDC supply), **21** (CRDC bypass), and **22** (CRDC focal-plane bypass). The rest of the valves should be closed
-  * Ensure that the manual venting valve located on the south side of the chamber is closed (see figures below)  {{:wiki:fp-venting-valve-Daniel.jpg?350|FP chamber manual venting valve}} {{:wiki:fp-venting-valve.jpg?350|FP chamber manual venting valve}}
-  * 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 "OPEN". The pressure should remain constant because the manual venting valve is still closed
-  * 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)
-{{:wiki:fp-pirani.jpg?350|FP chamber manual venting valve}}
-  * 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 "PUMPDOWN STOPPED"
+{{:wiki:IIGHShardware.jpg?600|Gas Handling System of S800 Intermediate Image}}
+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:ii-ppac-ghs-css.png|}}
+The layout of the II-GHS is shown below.
+{{:wiki:ii-ppac-ghs-layout.png|}}
+The operational states of the II-GHS are shown in the diagram below.
+{{:wiki:ii-ppac-ghs-operationalstates.png|}}
+===== 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 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:VP_RD while filling. Ion gauge reading will increase but should remain <1E-5 Torr when PPACs are running at full pressure.
+  - 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.

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