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venting_pumping_intermediate_image_box [2017/06/12 14:25] pereira [Venting/pumping Intermediate Image box and filling PPACs with gas] |
venting_pumping_intermediate_image_box [2017/06/12 14:49] pereira [Vent focal-plane chamber] |
{{:wiki:IIGHShardware.jpg?600|Gas Handling System of S800 Intermediate Image}} | {{:wiki:IIGHShardware.jpg?600|Gas Handling System of S800 Intermediate Image}} |
==== Vent focal-plane chamber ==== | ==== Vent focal-plane chamber ==== |
* Open the [[hv_bias|HV Remote Control]] GUI and ensure that the focal-plane detectors are unbiased | Requirements: PanelMate files **S3_Gas_Handling** and **S800Vac** |
* 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}} | * Verify that PPACs are in automatic mode with gas removed (**S3_Gas_Handling**) |
* Ensure that the FP ion gauge (I264IG) is off (see details [[vacuum_control|here]]) | * The "GH System Status box should read "Auto Mode Gas Removed" |
* 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 | * 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 |
* 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) | * Verify that PPACs are not biased: |
{{:wiki:fp-pirani.jpg?350|FP chamber manual venting valve}} | * Check that the detectors are unbiased by opening the [[HV bias|HV GUI]] |
* 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" | * 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.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.jpg?350|S800vac Panel Mate: start venting}}. |
| * When pressure in **I215PG** reaches atmospheric pressure, stop the venting process by selecting the box "VENT STATUS" and clicking "STOP VENTING PROCESS" {{:wiki:iis800vac_stopventing.jpg.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" |
| * You can now open the chamber |
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