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venting_pumping_intermediate_image_box [2018/08/14 10:52]
pereira [Pumping Intermediate-image chamber]
venting_pumping_intermediate_image_box [2018/12/20 15:16] (current)
pereira [Removing gas from Intermediate-image delay PPAC]
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 ====== Venting/​pumping Intermediate Image box and filling PPACs with gas ====== ====== Venting/​pumping Intermediate Image box and filling PPACs with gas ======
 +  * [[#General information]]
 +  * [[#Vent Intermediate-image chamber|Venting Intermediate-image chamber]]
 +  * [[#Pumping Intermediate-image chamber]]
 +  * [[#​Filling/​Removing gas in Intermediate-image delay PPAC]]
 +
 +===== 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 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 (NOTE: This figure was taken from the A1900 GHS included in Barney. A similar GUI for the S800 II PPACs is not yet available): 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 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 (NOTE: This figure was taken from the A1900 GHS included in Barney. A similar GUI for the S800 II PPACs is not yet available):
  
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         * Check that the detectors are unbiased by opening the [[HV bias|HV GUI]]         * 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"​         * Notify the system of the bias-off state by selecting the "​I214BON_CONFIRM"​ box in **S3_Gas_Handling** and clicking "PP BIAS OFF CONFIRMED"​
 +  * Open **S800Vac** and go to page 03 ("​Intermediate image box vacuum system sec 15")
   * Isolate chamber by closing gate valves **I212GV** and **I215GV**   * Isolate chamber by closing gate valves **I212GV** and **I215GV**
   * [[Vacuum control|Turn off]] ion gauge **I213IG** ​   * [[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" ​   * Check box "​PUMPDOWN STATUS INTERMEDIATE IMAGE BOX". It should read "Good vacuum" ​
 {{:​wiki:​iis800vac_pumped.jpg?​500|S800vac Panel Mate}}. ​ {{:​wiki:​iis800vac_pumped.jpg?​500|S800vac Panel Mate}}. ​
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           * (Note: sometimes it is necessary to repeat this operation a couple of times). ​           * (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    * At the end of the procedure, close the manual roughing pump valve 
 +
 +
 +
 +
 +===== Filling/​Removing gas in Intermediate-image delay PPAC =====
 +
 +{{:​wiki:​ghsiippacs.png?​1000|Gas Handling System of S800 Intermediate Image}} ​
 +
 +Requirements:​ PanelMate files **S3_Gas_Handling** and **S800Vac**
 +
 +==== Filling Intermediate-image delay PPAC with gas ====
 +  * 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 "​I214BON_CONFIRM"​ box in **S3_Gas_Handling** and clicking "PP BIAS OFF CONFIRMED"​
 +  * 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 "​I214BON_CONFIRM"​ box should indicate "PP BIAS OFF CONFIRMED",​ and the only valves that should be open in **S3_Gas_Handling** are the "Det Bypass"​ (V5) and "Chmbr Bypass"​ (V6); the rest of the valves (Gas Sup V1, Gas Lin Pmp Out V2, Flow Bypass V3, Det Return V4, and I214V_NCL (enable)) should be closed
 +  * Confirm that PanelMate box "​I214P_AUTO/​MAN Pre Set" reads 5 Torr (the set gas pressure in the detector) ​
 +  * Open the gas bottle valve (sitting near the gas handling system)
 +  * PanelMate box "Gas Flow Control"​ should indicate "OK to Start Gas Flow". Select that box and click on "Start Gas Flow"
 +        * Valve V2 (Gas lin pmp out) will be opened and I214V_NCL will change from closed to "​ENABLED"​
 +        * 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
 +
 +
 +
 +
 +==== Removing gas from Intermediate-image delay PPAC ====
 +  * 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 "​I214BON_CONFIRM"​ box in **S3_Gas_Handling** and clicking "PP BIAS OFF CONFIRMED"​
 +  * Verify that PPACs are in automatic mode with gas flowing (**S3_Gas_Handling**)
 +        * The "GH System Status box should read "Auto Gas Flow Estab"
 +        * If gas is flowing 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 "​I214BON_CONFIRM"​ box should indicate "PP BIAS OFF CONFIRMED",​ and the valves should indicate:
 +              * I214 Gas Sup V1 (open)
 +              * Gas Lin Pmp out V2 (closed)
 +              * Flow Bypass V3 (closed)
 +              * Det Return V4 (open)
 +              * Det Bypass V5 (closed)
 +              * Chmbr Bypass (closed)
 +              * I214V_NCL (enabled) ​
 +  * PanelMate box "Gas Removal Control"​ should indicate "OK to Start Gas Removal"​. Select that box and click on "Start Gas Removal"​
 +        * Valves V1 (I214 Gas Sup) and I214V_NCL will close 
 +        * Valves V3 (Flow Bypass) and Det Bypass (V5) will open
 +        * I214CM Press Rdg will gradually decrease to zero
 +        * GH System status should indicate "Gas Removal"​
 +  * When the gas is removed from the detector
 +        * Valve V3 (Flow Bypass) and 4 (Det return) will close
 +        * Valve V6 (Chamber Bypass) will open
 +        * GH System status will indicate "Gas Removed"​
 +        * I214BON_CONFIM will change to "PPAC BIAS ASSUMED ON"
 +        * The valves status will be: V1 (closed), V2 (closed), V3 (closed), V4 (closed), V5 (open), V6 (open), I214V_NCL (closed)
 +
 +
  
venting_pumping_intermediate_image_box.1534258323.txt.gz ยท Last modified: 2018/08/14 10:52 by pereira