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gas_handling_system [2017/01/22 16:51] pereira [Detector gas handling system] |
gas_handling_system [2023/05/11 11:26] pereira [Detector gas handling system] |
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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). | ||
- | * [[# | + | * [[# |
- | * [[#LabView Control Program]] | + | * [[# |
- | * [[# | + | * [[#Tracking |
- | * [[#Filling Ion Chamber with Gas]] | + | * [[#Replacing |
- | * [[#Filling CRDC1 and CRDC2 with Gas]] | + | |
- | * [[# | + | |
- | * [[Tracking Gas bottles pressures from Barney||#Tracking | + | |
- | + | ||
- | ===== 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 | + | ===== General Information for 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 | + | 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: |
- | ===== LabView Control Program | + | * [[venting_pumping_intermediate_image_box|[venting_pumping_intermediate_image_box|Venting/ |
- | To start the gas handling system control application, | + | * [[installation_fp_sci|Venting/ |
+ | * | ||
+ | * [[venting_pumping_intermediate_image_box|Venting/ | ||
+ | ===== Preparation of Gas bottles for filling of focal-plane detectors | ||
- | * 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: |
- | | + | Adjusting the pressured reading from a scale (for instance isobutane) requires some special guidelines. In the case of isobutane, the following EPICs PVs are involved: |
+ | | ||
+ | | ||
+ | | ||
+ | | ||
+ | * I265DGWN: net weight, as marked in the bottle (e.g. 5 lb) | ||
+ | * I265DGWG: gross weight, as marked in the bottle (e.g. 41.6 lb) | ||
+ | * I265DGWS: weight, as read from the scale | ||
+ | * I265DGWC: correction factor used to match the scale weight and gross weight when the full bottle is installed. | ||
+ | * I265DGW: net weight deduced from the scale | ||
- | * Fill Ion chamber | ||
- | * Enter the desired fill pressure and start the automatic filling process | ||
- | * Click on the tab labeled **Slot 8 (M-card) IC** to access the page with the pressure set point control | ||
- | * Enter the desired pressure (typically 300 Torr) in the field under the knob labeled 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) | ||
- | * If necessary, the filling process can be stopped at any time by pressing the valve button labeled **Close MFC #1** | ||
- | * Open **valve 9** | ||
- | * 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 the pressure of the focal plane vacuum chamber (as read out via the I264IG ion gauge in PanelMate **S800vac.MT2 page 07**) while detectors are being filled with gas; the pressure normally stays below 5 x 10< | + | ===== Replacing |
- | + | In preparation | |
- | * 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 (typically 40 Torr) in the field under the knob labeled **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 #2 and MFC #3 will increase. The LabView application controls the gas mixing ratio based on the flow ratio (scaled with a calibration constant) | + | |
- | * If necessary, the filling process can be stopped at any time by pressing the valve button labeled **Close MFCs #2 & #3** | + | |
- | * Open **valve 25** | + | |
- | * The filling process will take several minutes | + | |
- | + | ||
- | * When the detector is filled, close **valve 21** | + | |
- | + | ||
- | + | ||
- | ===== Removing | + | |
- | + | ||
- | * 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; the pressure normally stays below 5E-5 Torr | + | |
- | + | ||
- | * 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) | + | |
- | + | ||
- | * 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: | + | |
- | + | ||
- | * 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 9 and 25** | + | |
- | + | ||
- | * 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# | + | |
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- | + | ||
- | + | ||
- | {{: | + |