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gas_handling_system [2017/05/14 10:04] pereira [Filling Ion Chamber with Gas] |
gas_handling_system [2023/02/13 14:55] noji Old descriptions about controls in LabView have been eliminated and replaced with those in CS Studio. |
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====== Detector gas handling system ====== | ====== Detector gas handling system ====== | ||
- | * [[#General information]] | + | * [[#General information |
- | * [[#LabView Control Program]] | + | * [[# |
- | * [[#Preparation of Gas bottles|Preparation of Gas bottles for filling of detectors]] | + | |
- | * [[#Filling Ion Chamber with Gas]] | + | |
- | * [[#Filling CRDC1 and CRDC2 with Gas]] | + | |
- | * [[#Removing Gas from Focal Plane Detectors]] | + | |
* [[#Tracking Gas bottles pressures|Tracking Gas bottles pressures from Barney]] | * [[#Tracking Gas bottles pressures|Tracking Gas bottles pressures from Barney]] | ||
* [[# | * [[# | ||
- | ===== General Information ===== | + | ===== General Information |
- | Required controls and monitoring | + | |
- | * LabView gas handling system application **FPGHS_TCPIP-II.vi** | + | |
- | * PanelMate **S800vac.ui page 07**: Focal Plane Detector | + | |
- | The gas handling systems for both Focal Plane gas-filled detectors – the [[Detectors# | + | The gas handling systems for the gaseous detectors in both intermediate-image and focal-plane boxes are operated |
- | Note that since the same roughing pump drives the gas handling systems for both gas-filled | + | * [[venting_pumping_intermediate_image_box|[[venting_pumping_intermediate_image_box|Venting/ |
+ | * [[installation_fp_sci|Venting/ | ||
- | ===== LabView Control Program | + | ===== Preparation of Gas bottles for filling of focal-plane detectors |
- | To start the gas handling system control application, | + | |
- | * A log file should be specified before operating the gas handling system | + | ==== In Data-U4 ==== |
- | * A window automatically pops up asking for the name of the log file when the program starts | + | * Ensure **RBT_BTS34: |
- | * Use the number of the current experiment (or " | + | * Confirm that the focal plane chamber is under vacuum |
- | * The On indicator next to Is VI running? will flash until a log file is specified and the program initiates communications with the hardware | + | |
- | + | ||
- | * Click the **Valves** tab at the top of the LabView window to display the overview of the gas handling system (see Figure below) | + | |
- | * The triangles on the valve control buttons (as well as the square valve status indicators near the control buttons) are red to indicate that a valve is closed (e.g., control 25 for the CRDC return above) and green to indicate a valve is open (e.g., control 22 for the CRDC bypass above) | + | |
- | + | ||
- | * The gas handling control application should always remain open during the entire time either detector is filled with gas to ensure the log file is continuously updated | + | |
- | + | ||
- | * Once both detectors are empty, this application can be closed with the “X” button on the upper right corner of the window. | + | |
- | + | ||
- | {{: | + | |
- | + | ||
- | + | ||
- | ===== Preparation of Gas bottles ===== | + | |
- | + | ||
- | ==== In Data-U6 ==== | + | |
- | * Ensure **I265GV** is closed | + | |
- | * Confirm that the focal plane chamber is under vacuum | + | |
- | * Confirm that the only open gas handling system valves are **4, 5, 6, 20, 21, and 22** | + | |
- | * (Check section on [[vacuum control|vacuum control]] for further details.) | + | |
==== In the S3 vault ==== | ==== In the S3 vault ==== | ||
- | | + | |
- | | + | |
- | | + | |
- | * Ensure that the main valves on the gas bottles are open (see pictures below) | + | * Ensure that the main valves on the gas bottles are open (see pictures below) |
- | * Ensure that the gas bottles are not empty | + | * Open valves downstream of regulators in each bottle |
- | | + | |
- | | + | |
- | | + | |
- | | + | |
+ | | ||
{{: | {{: | ||
{{: | {{: | ||
- | ===== Filling Ion Chamber with Gas ===== | + | ===== Tracking |
+ | A rather conservative rule of thumb that helps estimate how much gas will be consumed during the course of an experiment assumes that when the detectors are filled and with gas running through them, the S800 IC detector consumes **~10 psi/day of P10**, and the CRDCs consume **~10 psi/day of CF4** and **~0.07 lb/day of Isobutane**. The process of filling the detectors, is approximately equivalent to 1 day of gas consumption during normal operations. | ||
- | * Follow instructions under [[# | ||
- | * Monitor | + | In order to track the status |
- | * Confirm that the detector pressure as indicated | + | The gas content of each bottle is tracked |
- | * To zero this display: | + | |
- | * Click on the **Slot 3 (PT1)** tab to access | + | |
- | * Click the **Zero Sensor** button | + | |
- | * Click the **Valves** tab at the top of the LabView window to return to the overview display of the gas handling system | + | |
- | * Close **valve 6** | + | When installing a full bottle in a scale (e.g. isobutane), it is important to follow a procedure to account for the differences between the weight measured by the scale, and the actual gross weight. After removing an empty bottle, proceed as follows: |
- | * Open **valve 2**; the flow reading | + | Adjusting |
- | + | * Check the weight marked | |
- | * Fill Ion chamber | + | * Check the gross and net weight in the bottle |
- | * Enter the desired fill pressure and start the automatic filling process | + | * Install |
- | * Click on the tab labeled **Slot 8 (M-card) IC** to access | + | * Update |
- | * Enter the desired pressure (typically 300 Torr) in the field under the knob labeled Set Point | + | |
- | * Click button labeled **Update Set Point** | + | |
- | * Click button labeled **Return to AUTO Mode** on left to start filling/ | + | |
- | * Click the **Valves** tab at the top of the LabView window to return to the overview display of the gas handling system to monitor filling. The flow readings for MFC #1 will increase and eventually disappear as the readout value overflows the display field (this is normal behavior) | + | |
- | * Open **valve 9** | + | |
- | * If necessary, the filling process can be stopped at any time by pressing the valve button labeled **Close MFC #1** | + | |
- | * The filling process will take several minutes | + | |
- | + | ||
- | * When the detector is filled, close **valve 5** | + | |
- | + | ||
- | + | ||
- | + | ||
- | ===== Filling CRDC1 and CRDC2 with Gas ===== | + | |
- | + | ||
- | * Follow instructions under [[# | + | |
- | + | ||
- | * Monitor | + | |
- | + | ||
- | * Confirm that the detector pressure as indicated by the display labeled P.T. #2 reads below a couple of Torr | + | |
- | * To zero this display: | + | |
- | * Click on the **Slot 4 (PT2)** tab to access the details page for PT #2 | + | |
- | * Click the **Zero Sensor** button | + | |
- | * Click the **Valves** tab at the top of the LabView window to return to the overview display of the gas handling system | + | |
- | + | ||
- | * Close **valve 22** | + | |
- | + | ||
- | * Open **valves 10 and 15** | + | |
- | + | ||
- | * Open **valve 12**; the flow reading at MFC #2 should jump momentarily | + | |
- | + | ||
- | * Open **valve 17**; the flow reading at MFC #3 should jump momentarily | + | |
- | + | ||
- | * Fill CRDCs | + | |
- | * Enter the desired fill pressure and start the automatic filling process | + | |
- | * Click the **Zero Sensor** button | + | |
- | * Click on the tab labeled **Virtual Ch. 0 (CRDC)** to access the page with the pressure set point control | + | |
- | * Enter the desired pressure | + | |
- | * Click button labeled **AUTO Mode** on left to start filling/ | + | |
- | * Click the **Valves** tab at the top of the LabView window to return to the overview display of the gas handling system to monitor filling. The flow readings for MFC #2 and MFC #3 will increase. The LabView application controls the gas mixing ratio based on the flow ratio (scaled with a calibration constant) | + | |
- | * Open **valve 25** | + | |
- | * If necessary, the filling process can be stopped at any time by pressing the valve button labeled **Close MFCs #2 & #3** | + | |
- | * The filling process will take several minutes | + | |
- | + | ||
- | * When the detector is filled, close **valve 21** | + | |
- | + | ||
- | + | ||
- | ===== Removing Gas from Focal Plane Detectors ===== | + | |
- | + | ||
- | * Monitor the pressure of the focal plane vacuum chamber (as read out via the I264IG ion gauge in PanelMate **S800vac.MT2 page 07**) while gas is being removed from detectors; | + | |
- | + | ||
- | * Ensure that the system is in the normal state for flowing gas through the detectors | + | |
- | * Confirm that the focal plane chamber is under vacuum | + | |
- | * Confirm that **the only open** gas handling system valves are **2, 4, and 9 for the Ion Chamber** and **10, 12, 15, 17, 20, and 25 for the CRDCs** | + | |
- | * Confirm that the detector pressures as indicated by the displays labeled P.T. #1 for the Ion Chamber and P.T. #2 for the CRDCs show the correct fill values (typically 300 Torr and 40 Torr, respectively) | + | |
- | + | ||
- | | + | |
- | + | ||
- | * Stop the gas flow into both detectors by clicking valve buttons labeled **Close MFC #1** and **Close MFCs #2 & #3** | + | |
- | + | ||
- | | + | |
- | + | ||
- | * Open **valves 5 and 21** | + | |
- | + | ||
- | * **IMPORTANT:** CLOSE **VALVE 25** to protect CRDCs from Ion Chamber pressure | + | |
- | + | ||
- | * Empty Ion Chamber to a pressure at or below the pressure of the CRDCs | + | |
- | * Open **valve 8** | + | |
- | * Wait for the Ion Chamber pressure to reach or drop below the pressure in the CRDCs; this process will take several minutes | + | |
- | + | ||
- | * Finish emptying both detectors | + | |
- | * Open **valve 25** | + | |
- | * Open **valve 24** | + | |
- | * Wait for the pressure in both detectors as indicated by the displays labeled P.T. #1 and P.T. #2 to reach 0.5 Torr or less; this process will take at least an hour | + | |
- | + | ||
- | | + | |
- | + | ||
- | * Close **valves 8 and 24** | + | |
- | + | ||
- | * Open **valves 6 and 22** | + | |
- | + | ||
- | * Enter S3 vault and close main valves on [[# | + | |
- | + | ||
- | ===== Tracking Gas bottles pressures ===== | + | |
- | In order to track the status of the gas bottles for the [[Detectors# | + | |