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gas_handling_system [2018/12/19 11:03] pereira [Detector gas handling system] |
gas_handling_system [2023/05/11 11:23] pereira [General Information for gas handling systems] |
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====== Detector gas handling system ====== | ====== Detector gas handling system ====== | ||
+ | The gas handling systems for the gaseous detectors in both intermediate-image and focal-plane boxes are operated remotely through CS studio. Their pages can be found on the EXP network through FRIB EXP Main → S800 → GHS Pages (Secondary Pages). | ||
* [[#General information for focal-plane gas handling system]] | * [[#General information for focal-plane gas handling system]] | ||
- | * [[#LabView Control Program for focal plane 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]] | ||
* [[# | * [[# | ||
- | * [[Venting/ | ||
- | ===== General Information for focal-plane gas handling system ===== | + | ===== General Information for gas handling systems ===== |
- | The gas handling systems | + | |
- | + | ||
- | Note that since the same roughing pump drives the gas handling systems for both gas-filled detectors, extra precautions must be taken to protect one detector from the pressure of the other detector. The fact that the same pump drives both systems is not indicated on the graphics for the LabView control application | + | |
- | + | ||
- | Required controls and monitoring | + | |
- | * LabView gas handling system application **FPGHS_TCPIP-II.vi** | + | |
- | * PanelMate **S800vac.ui page 07**: Focal Plane Detector | + | |
- | + | ||
- | ===== LabView Control Program for focal plane detectors ===== | + | |
- | To start the gas handling system control application, | + | |
- | + | ||
- | * A log file should be specified before operating the gas handling system | + | |
- | * A window automatically pops up asking for the name of the log file when the program starts | + | |
- | * Use the number of the current experiment (or " | + | |
- | * 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. | + | |
- | + | ||
- | {{: | + | |
+ | The gas handling systems for the gaseous detectors in both intermediate-image and focal-plane boxes are operated remotely through CS studio. Their pages can be found on the EXP network through FRIB EXP Main → S800 → GHS Pages (Secondary Pages). Detailed instructions are found in the following pages: | ||
+ | * [[venting_pumping_intermediate_image_box|[venting_pumping_intermediate_image_box|Venting/ | ||
+ | * [[installation_fp_sci|Venting/ | ||
+ | * [Venting/ | ||
===== Preparation of Gas bottles for filling of focal-plane detectors ===== | ===== Preparation of Gas bottles for filling of focal-plane detectors ===== | ||
- | ==== In Data-U6 ==== | + | ==== In Data-U4 ==== |
- | * Ensure **I265GV** is closed | + | * Ensure **RBT_BTS34: |
- | * Confirm that the focal plane chamber is under vacuum | + | * Confirm that the focal plane chamber is under vacuum |
- | * Confirm that the only open gas handling system valves are **4, 5, 6, 7, 20, 21, 22 and 23** | + | |
- | * (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) |
- | * Open valves downstream of regulators in each bottle | + | * Open valves downstream of regulators in each bottle |
- | * Ensure that the gas bottles are not empty | + | * Ensure that the gas bottles are not empty |
- | | + | |
- | | + | |
- | | + | |
- | | + | |
{{: | {{: | ||
{{: | {{: | ||
- | ===== 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 **valves 6** and **7** | + | 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, |
- | * 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 the following EPICS PVs with the correct values: |
- | * 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 **valves 22** and **23** | + | |
- | + | ||
- | * 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 | + | |
- | * Click on the tab labeled **Virtual Ch. 0 (CRDC)** to access the page with the pressure set point control | + | |
- | * Enter the desired pressure (typically 40 Torr) in the field under the knob labeled **Set Point** | + | |
- | * Click button labeled **Update | + | |
- | * 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 #2 and MFC #3 will increase. The LabView application controls the gas mixing ratio based on the flow ratio (scaled | + | |
- | * Open **valve 25** | + | |
- | * If necessary, | + | |
- | * The filling process will take several minutes | + | |
- | + | ||
- | * When the detector is filled, close **valve 21** | + | |
- | + | ||
- | + | ||
- | ===== Removing Gas from Focal Plane Detectors ===== | + | |
- | + | ||
- | * Monitor | + | |
- | + | ||
- | | + | |
- | * 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 | + | |
- | + | ||
- | * Ensure that I265GV is closed to isolate focal plane vacuum chamber from spectrograph | + | |
- | + | ||
- | * Stop the gas flow into both detectors by clicking valve buttons labeled **Close MFC #1** and **Close MFCs #2 & #3** | + | |
- | + | ||
- | * Isolate the gas supply by closing **valves 2, 12, 17, 10, and 15** | + | |
- | + | ||
- | * Open **valves 5 and 21** | + | |
- | + | ||
- | * **IMPORTANT**: Before opening valve 8 (next step), 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 | + | |
- | + | ||
- | * 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, 7, 22 and 23** | + | |
- | + | ||
- | * Enter S3 vault and close valves downstream of regulators in [[# | + | |
- | + | ||
- | ===== Tracking Gas bottles pressures ===== | + | |
- | In order to track the status of the gas bottles for the [[Detectors# | + | |