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installation_fp_sci [2017/06/20 17:16] pereira [Vent focal-plane chamber] |
installation_fp_sci [2023/05/08 16:39] noji |
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- | ====== | + | ====== |
- | ===== Vent focal-plane chamber | + | //In June 2019, a new Turbo Pump with magnetically-levitating bearings (Leybold MAG 2200iP) was installed in the S800 focal-plane chamber. This pump has a dry-N line connected to it that is purging continuously the bearings. This creates an extra pressure in the foreline, which must be pumping down continuously. Therefore, it is critical turn off the turbo pump whenever the foreline valve needs to be closed.// |
- | * Open the [[hv_bias|HV Remote Control]] GUI and ensure that the focal-plane detectors are unbiased | + | |
- | | + | The GHS for the focal plane is operated remotely through CS studio. Its page can be found on the EXP network through FRIB EXP Main → S800 → GHS Pages (Secondary Pages) → FP Main Page and is shown below. |
- | * Ensure that the manual venting valve located | + | |
- | * Ensure that the FP ion gauge (I264IG) is off (see details [[vacuum_control|here]]) | + | {{: |
- | | + | |
- | | + | Instructions on how to vent/ |
- | | + | |
- | {{:wiki:fp-pirani.jpg?350|FP chamber manual venting | + | ===== Emptying FP Gaseous Detectors ===== |
- | | + | |
- | * When the chamber is fully vented, select | + | - Return to “GHS_FP_Main” click **Enable MFC Controls** |
- | | + | - Set MFC1 to 0 sccm to stop the flow of P10 to the IC vessel |
+ | - Set MFC2 to 0 sccm. This will cause MFC3 to also go to zero through the ratio control. The flow of iC4H10 and CF4 to the CRDC chamber will cease. | ||
+ | - Click **Enable Controls** for the CRDC and IC Control Valve PIDs and then click **DISABLE** for each of them. This will open the control valve to 100% for each vessel and begin pumping them out. | ||
+ | - The IC vessel has a much larger quantity of gas compared to the CRDC vessel. In order to pump them out at a similar speed go to the “FP_State_Buttons” page and go to the D2708 (IC vessel) tab. Click **MAN** to enable manual mode. Click **OPN** for “S800_GHS: | ||
+ | - Open a data browser and plot the PVs for PT1 (S800_GHS: | ||
+ | | ||
+ | |||
+ | ===== Venting FP Chamber ===== | ||
+ | - Ensure the IG in the Focal Plane Pumping Station is off. This page can be found in FRIB EXP Main → S800 → Vacuum Main (Primary Pages) → Focal Plane. | ||
+ | - Return to the “FP_State_Buttons” page and for each of the D2708 and D2703 tabs click **PUMP**. | ||
+ | | ||
+ | - Once the FPG bottoms out, check the box next to “Valve Controls”, | ||
+ | - If the system will only be vented for a short time, leave the TMP on, otherwise turn it off. | ||
+ | - Plot PT1 (S800_GHS:CMG_D2708A:VP_RD), PT2 (S800_GHS: | ||
+ | | ||
+ | | ||
+ | | ||
+ | |||
+ | The CRDC (Purple) and IC (Green) vessel pressures during Emptying and Venting procedures outlined above are shown below. | ||
+ | |||
+ | {{:wiki:crdc_ic_pressures_during_empty_vent.png|}} | ||
+ | |||
+ | ===== Pumpdown of FP Chamber ===== | ||
+ | |||
+ | - Open “Focal Plane Pumping Station” page from FRIB EXP Main → S800 → Vacuum Main (Primary Pages). | ||
+ | - Open “GHS_FP_Main” and “FP_State_Buttons” pages from FRIB EXP Main → S800 → GHS Pages (Secondary Pages). | ||
+ | | ||
+ | - On the “FP_State_Buttons” page change from “Vent” mode to “Pump” mode by clicking | ||
+ | - Check the box next to “Valve Controls” on the “D2686 Pumping Station” | ||
+ | - If the TMP is off and Foreline Valve (FV) is closed, open the Roughing Valve (RV) briefly (2 seconds) by clicking **Open** and observe the behavior of the pressure gauges. If they all decrease at the same rate, again click **Open** to begin roughing out the chambers. | ||
+ | | ||
+ | - When the BPG reads below 200 mTorr, | ||
+ | - NOTE: before TMP reaches | ||
+ | | ||
+ | - On the “FP_State_Buttons” page click **RUN** to enter run mode. | ||
+ | |||
+ | ===== Filling & Running FP Gaseous Detectors ===== | ||
+ | |||
+ | - Plot PT1 (S800_GHS: | ||
+ | | ||
+ | | ||
+ | - Click **Enable MFC Controls**. | ||
+ | - Set MFC1 to 25 sccm. Ensure PT1 begins to increase in pressure. | ||
+ | - Set MFC2 to 8 sccm. Ensure MFC3 automatically sets to 32 sccm and PT2 begins to increase in pressure. | ||
+ | - The IC vessel is a much larger chamber than the CRDC vessel and needs to reach a higher operating pressure. In order to fill the vessel in a timely manner it is safe to override the MFC and set it to “Fully Open”. To do this select “Fully Open MFC” in the dropdown menu next to MFC1. | ||
+ | - If desired, the CRDC vessel can be filled with MFC2 set to 16 sccm. Be ready to decrease MFC2 back to 8 sccm at **35 Torr** as the PID controls are not calibrated to prevent the vessel from overpressurizing at this increased flow. Allow the CRDC vessel to slowly approach 40 Torr. | ||
+ | - As the vessels approach their setpoints the Control Valves | ||
+ | | ||
+ | - Once PT1 reaches | ||
+ | | ||
+ | - The PID controls for each vessel are calibrated to maintain their respective setpoints to within +/- 0.1 Torr. If the operator notices a larger variation after an hour of PID control, notify Brandon Ewert. | ||
+ | |||
+ | ====== Opening/ | ||
+ | |||
+ | Instructions on how to open/close the focal-plane chamber are described below. | ||
===== Open focal-plane chamber ===== | ===== Open focal-plane chamber ===== | ||
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* Turn on the switch to activate the motor opening the chamber. It takes about 10 minutes to get the chamber totally opened {{: | * Turn on the switch to activate the motor opening the chamber. It takes about 10 minutes to get the chamber totally opened {{: | ||
+ | ===== Closing focal-plane chamber ===== | ||
+ | * Turn the switch to move the chamber to position " | ||
+ | * Check the display indicating the weight lift by the hydraulic system. When the chamber is close, the weight displayed will increase drastically due to the resistance experienced by the hydraulic system. At that point, stop immediately the lifting switch (otherwise, a weight-limit set point might be reached, disabling the hydraulic system) | ||
+ | * Turn the knob to close the clamps | ||
+ | * Inspect the clamps and chamber flange (no gaps) to ensure that the chamber is properly sealed | ||
+ | * Before pumping the chamber down, make sure that the scintillator is properly connected. This can be done by biasing the detector and checking the signals, either from the scalers or with a scope. One should clearly see cosmic rays; if that is not the case, the phototubes are likely miss connected | ||
+ | |||
+ | ====== Installing FP scintillator ====== | ||
- | ===== Installing FP scintillator | + | Instructions on how to install the focal-plane |
* The figure below shows the FP chamber open, with the " | * The figure below shows the FP chamber open, with the " | ||
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- | ===== Closing focal-plane chamber ===== | ||
- | * Turn the switch to move the chamber to position " | ||
- | * Check the display indicating the weight lift by the hydraulic system. When the chamber is close, the weight displayed will increase drastically due to the resistance experienced by the hydraulic system. At that point, stop immediately the lifting switch (otherwise, a weight-limit set point might be reached, disabling the hydraulic system) | ||
- | * Turn the knob to close the clamps | ||
- | * Inspect the clamps and chamber flange (no gaps) to ensure that the chamber is properly sealed | ||
- | * Before pumping the chamber down, make sure that the scintillator is properly connected. This can be done by biasing the detector and checking the signals, either from the scalers or with a scope. One should clearly see cosmic rays; if that is not the case, the phototubes are likely miss connected | ||
- | |||
- | ===== Pumping focal-plane chamber ===== | ||
- | * Make sure that the pressure-relief valve and the manual vent valve (see above) are closed. | ||
- | * Make sure that manual valve of the mechanical pump is opened {{: | ||
- | * Open PanelMate **S800vac** and go to page 07. Make sure | ||
- | * Select window **PUMPDOWN STATUS** and click on button **START PUMPDOWN**. The **PUMPDOWN STATUS** and **VENT STATUS** windows should display " | ||
- | * Wait for some hours until vacuum is good |