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--- venting_pumping_intermediate_image_box [2017/06/12 14:55]
pereira
+++ venting_pumping_intermediate_image_box [2023/02/13 14:40]
noji The title has been modified so it is similar to the FP GHS page.
@@ Line 1: / Line 1: @@
-====== Venting/pumping Intermediate Image box and filling PPACs with gas ======
+====== Venting/pumping II chamber & emptying/filling gaseous detectors ======
-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 safety. The system is schematically illustrated in the figure below. It shows the status of the valves (red: closed, white: open) when the intermediate image chamber is under vacuum and the PPACs are filled with gas:
+  * [[#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 =====
+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):
-The II-GHS equipment (valves, flow-meter, pipes, etc.) are located on the west balcony of the top level in the S3 vault (see figure below):
 {{: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|}}
-===== Vent focal-plane chamber =====
+===== Emptying Detectors =====
-Requirements: PanelMate files **S3_Gas_Handling** and **S800Vac**
+  - Set “PPAC Setpoint” to 0 Torr.
+  - Click **EMPTY** on the “GHS_II-PPAC_Main” page to begin pumping out the gas quickly.
-  * Verify that PPACs are in automatic mode with gas removed (**S3_Gas_Handling**)
+  - When “PPAC Pressure” reads < 0.1 Torr, click **MAN** and then **AUTO**. This will release the remaining gas into the diagnostics box.
-        *  The "GH System Status box should read "Auto Mode Gas Removed"
+  - Monitor D2340 pumping station and ensure the TMP stays on and TGV remains open. If not, contact the Vacuum Operation group.
-        * 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" and "Chmbr Bypass
+  - 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.
-  * Verify that PPACs are not biased:
+    * 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.
-        * Check that the detectors are unbiased by opening the [[HV bias|HV GUI]]
-        * Notify the system of the bias-off state by selecting the "I214BON_CONFIRM" box in **S3_Gas_Handling** and clicking "PP BIAS OFF CONFIRMED"
-  * Isolate chamber by closing gate valves **I212GV** and **I215GV**
-  * [[Vacuum control|Turn off]] ion gauge **I213IG**
-  * Open **S800Vac** and go to page 03 ("Intermediate image box vacuum system sec 15")
-  * Check box "PUMPDOWN STATUS INTERMEDIATE IMAGE BOX". It should read "Good vacuum"
-{{:wiki:iis800vac_pumped.jpg?350|S800vac Panel Mate}}.
-  * In order to begin venting process, select that box and click "BEGIN VENTING PROCEDURE"
-        * Box "VENT STATUS" should change from "VENT PROCEDURE STOPPED" to "WAITING FOR VENT TIMER".
-        * Turbo gate valve **I214GV** will be automatically closed and pressure in chamber will start rising (as seen in **I215PG**) {{:wiki:iis800vac_startventing.jpg?350|S800vac Panel Mate: start venting}}.
-        * When **I215PG** reads atmospheric pressure, select the box "VENT STATUS" and click "STOP VENTING PROCESS". {{:wiki:iis800vac_stopventing.jpg?350|S800vac Panel Mate: stop venting}}.
-        * The status in the box "VENT STATUS" should change from "WAITING FOR VENT TIMER" to "VENT PROCEDURE STOPPED"
+===== Filling and Running Detectors =====
-        * You can now open the chamber
+  - 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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