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--- installation_fp_sci [2019/12/10 20:26]
pereira [Vent focal-plane chamber]
+++ installation_fp_sci [2023/02/13 12:05]
noji Updated descriptions about the FP GHS based upon "S800 Focal Plane Gas Handling System Operation Manual" (v3) provided by Jorge to SN on 2/12/2023.
@@ Line 1: / Line 1: @@
-====== Installation of focal-plane scintillator ======
+====== Venting/pumping FP chamber & emptying/filling gaseous detectors ======
-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.
+//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.//
-Instructions on how to vent/pump-down the focal-plane chamber are described below.
+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.
-===== Vent focal-plane chamber =====
-  * Open the [[hv_bias|HV Remote Control]] GUI and ensure that the gas focal-plane detectors (both CRDCs and the Ion Chamber) are unbiased
+{{:wiki:fp-ghs-css.png|}}
-  * Make sure that the CRDC grid gate is off (HV is in dU6)
-  * Make sure that the CRDC preamps and interface boards are turned off (it is located in the NIM crate attached to the S800 focal-plane chamber)
+Instructions on how to vent/pump-down the focal-plane chamber and empty/fill and run detectors are described below.
-  * In order to avoid condensation from the cooling system, turn off the chiller sitting under the S800 focal-plane chamber. Wait for at least a couple of hours before venting the chamber.
-  * Open the [[gas_handling_system#labview_control_program|Labview gas handling system]] and verify that there is no gas in the CRDCs and IC. Make sure that the only open valves are **4** (IC supply), **5** (IC bypass), **6** (IC focal-plane bypass), **7** (Ion Chamber vent), **20** (CRDC supply), **21** (CRDC bypass), and **22** (CRDC focal-plane bypass) and **23** (CRDC vent). The rest of the valves should be closed
+===== Emptying FP Gaseous Detectors =====
-  * Ensure that the manual venting valve located on the south side of the chamber is closed (see figures below)  {{:wiki:fp-venting-valve-Daniel.jpg?350|FP chamber manual venting valve}} {{:wiki:fp-venting-valve.jpg?350|FP chamber manual venting valve}}
+  - Check that the system is in **RUN** mode on the “FP_State_Buttons” page under FRIB EXP Main → S800 → GHS Pages (Secondary Pages)
-  * Ensure that the FP ion gauge (I264IG) is off (see details [[vacuum_control|here]])
+  - Return to “GHS_FP_Main” click **Enable MFC Controls**
-  * Open PanelMate and select **S800vac** file in directory \\exp\files\control\ncsdata\General\Qt\Templates, and go to page 07 (see figure below)
+  - Set MFC1 to 0 sccm to stop the flow of P10 to the IC vessel
-{{:wiki:NewPanelMate-S800FPVac.jpg?950|Panel Mate Vacuum FP chamber}}
+  - 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.
-  * Close I265GV (gate valve separating FP box from rest of beam line) is closed.
+  - 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.
-  * Click on the **VENT STATUS** window and begin the venting procedure. The **VENT VALVE I260VV** window will turn red and display "OPEN". The pressure should remain constant because the manual venting valve is still closed. The turbo GV **I260GV** will be closed, isolating the turbo pump from the focal-plane chamber.
+  - 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:SV_D2708:OPN_CMD_10” to open an additional valve to the pump.
-  * Gently open the manual venting valve until the pressure displayed in the Pirani Gauge (see figure below) increases by ~1 torr every 15 seconds (see figures below)
+  - Open a data browser and plot the PVs for PT1 and PT2.
-{{:wiki:fp-pirani.jpg?350|FP chamber manual venting valve}}
+  - Wait for PT1 and PT2 to read < 2 Torr. This should take about 30 minutes.
-  * Make sure that pressure inside the CRDCs and IC detectors (LabView) increase at the same rate than the pressure in the chamber. Otherwise, stop the venting process inmediately.
-  * Wait until the chamber is vented (few hours). The **I261PG** Pirani Gauge should read slightly above atmospheric pressure (due to the dry N2 flow pumped to the chamber). The window **VENT STATUS** in PanelMate should display "VENT VALVE OPEN". The window **PUMPDOWN STATUS** should display "PUMPDOWN STOPPED"
+===== Venting FP Chamber =====
-  * Meanwhile, turn the turbo pump off using PanelMate **S800vac**: select box **Turbo pump focal plane detector I260TP** can clock "Stop". It will take several minutes to fully stop (you can check the turbo-pump speed in box **I260TP SPEED**, or using EPICS channel **I260TP_FR_RD**)
+  - 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.
-  * When the Turbo pump is fully stopped, switch off the chiller located near the S800 electronics rack
+  - Return to the “FP_State_Buttons” page and under the D2708 tab click **AUTO**. This will close all valves and allow the system to enter Vent mode.
-  * When the chamber is fully vented, select **VENT STATUS** and click **STOP VENTING PROCEDURE**. This will automatically close the vent valve **I260VV**
+  - Click **VENT**. This will expose the vessels to the Pumping Station. Observe the FPG on the “D2430 Pumping Station” page to ensure the Turbo Pump is not overloaded.
-  * Close the manual vent valve
+  - Once the FPG bottoms out, check the box next to “Valve Controls”, then click **Close** next to the Turbo Gate Valve (TGV).
+  - If the system will only be vented for a short time, leave the TMP on, otherwise turn it off.
+  - Plot PT1, PT2, and PT3 from the “GHS_FP_Main” page as well as BPG from the “D2430 Pumping Station” page on the same axis.
+  - Briefly (~2 seconds) open the vent valve by clicking **Open** next to the valve labeled “Vent” then click **Close**. Check that all the pressures are increasing at the same rate.
+  - Again, open the vent valve and observe the pressure for 30 seconds to ensure the pressures are increasing at the same rate among all four gauges. If a difference of > 1 Torr is observed between any two gauges, click **Close** on the vent valve.
+  - Allow the pressure to rise to ~735 Torr over the next hour. The vent valve __should__ close itself at 735 Torr but be ready to close it manually if an error occurs.
+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).
+  - Plot PT1, PT2, and PT3 from the “GHS_FP_Main” page as well as BPG from the “D2430 Pumping Station” page on the same axis.
+  - On the “FP_State_Buttons” page change from “Vent” mode to “Pump” mode by clicking **PUMP** in both the D2703 and D2708 tabs.
+  - Check the box next to “Valve Controls” on the “D2686 Pumping Station” page.
+  - 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 rouging out the chambers.
+  - If the TMP is still on (this could be the case for a short vent period), click **Close** on the FV to protect the pump before doing step 6.
+  - When the BPG reads zero, **Close** RV and **Open** FV. Turn the TMP on if it is not already. When the TMP is “at speed” **Open** the TGV. If the TMP was off before opening the TGV, the chamber pressure may have risen to a point where the TGV closes automatically. If the BPG still reads < 1 Torr, attempt to **Open** the TGV again.
+  - Allow the TMP to pump on the system until the IG reads < 1E-5 Torr.
+  - On the “FP_State_Buttons” page click **RUN** to enter run mode.
+===== Filling & Running FP Gaseous Detectors =====
+  - Plot PT1, PT2, and the control valves for both D2703 (CRDC) and D2708 (IC).
+  - Click **Enable Controls** for the CRDC and IC “Control Valve PID”s, then click **ENABLE** to turn on PID controls for each vessel. Each control valve should adjust to its BASE value.
+  - If the CRDC valve remains completely open (stuck at 100%), open a probe with PV: “S800_GHS:CV_D2703:MODE_CSET_PVC”. In the “New Value” box, enter “CLOSE” and press enter. If the valve then closes (100% to 0%), enter “AUTO” in the “New Value” box and press enter. This should reenable PID control.
+  - 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 should begin to increase from their BASE values in order to equalize the pressure around the setpoint. Note that the CRDC pressure will change much faster than the IC pressure and has a much smaller tolerance. If PT2 reaches **45 Torr** the system will immediately enter “EMPTY” mode to prevent the foil disc from bursting. Use the figure below for reference. {{:wiki:crdc_vessel_filling_with_pid_control.png|}}
+  - If PT2 reaches **44 Torr** and the control valve is not open enough to start decreasing the pressure, immediately set MFC2 to 0 sccm and allow the valve to begin decreasing the pressure before resetting MFC2 back to 8 sccm. Notify Brandon Ewert (ewert@frib.msu.edu). Continue to monitor the pressure and control valve behavior to ensure the PID is in control of the pressure.
+  - Once PT1 reaches **300 Torr**, adjust MFC1 back to 25 sccm by selecting “Go to MFC Setpoint” in the dropdown menu next to MFC1. The pressure will equilibriate down to about **299.5 Torr**. Allow the IC vessel to slowly approach 300 Torr. Use the figure below for reference.{{:wiki:ic_vessel_filling_with_pid_control.png|}}
+  - The control valve for the IC vessel is set to react slowly as the vessel has a long pressure period. The valve will not “wake up” until 300 Torr is reached on PT1. This is okay as long as the control valve begins to open by this point. The pressure change is slow enough that over the next hour the valve will open enough to catch the pressure before it exceeds 305 Torr, well within the operating limit (500 Torr).
+  - 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/closing FP chamber ======
+Instructions on how to open/close the focal-plane chamber are described below.
 ===== Open focal-plane chamber =====
@@ Line 32: / Line 74: @@
   * Turn on the switch to activate the motor opening the chamber. It takes about 10 minutes to get the chamber totally opened {{:wiki:fp-chamber-motor.jpg?250|Motor switch to open FP chamber}}
+===== Closing focal-plane chamber =====
+  * Turn the switch to move the chamber to position "UP", and keep it that way for about 10 minutes (the time it takes the chamber to be closed)
+  * 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 scintillator are described below.
   * The figure below shows the FP chamber open, with the "old" FP scintillator to be replaced by the new one {{:wiki:E1-view.jpg?350|FP chamber opened}}
@@ Line 44: / Line 94: @@
-===== Closing focal-plane chamber =====
-  * Turn the switch to move the chamber to position "UP", and keep it that way for about 10 minutes (the time it takes the chamber to be closed)
-  * 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 (the valve **I260RV** will be automatically opened in the next step) {{:wiki:ManualValve-fp.jpg?350|Manual valve pump}}
-  * Open the gas-handling-system LabView control and make sure that the only open detector valves are **4** (IC supply), **5** (IC bypass), **6** (IC focal-plane bypass), **7** (Ion Chamber vent), **20** (CRDC supply), **21** (CRDC bypass), and **22** (CRDC focal-plane bypass) and **23** (CRDC vent). The rest of the valves should be closed. The pressure inside the detectors should be ~760 Torr.
-  * Open PanelMate **S800vac** and go to page 07. Make sure that the venting valve **I260VV** is closed (see last step of the [[#Vent focal-plane chamber|venting process]] described above)
-  * Make sure that the turbo pump is off (as seen in PanelMate **s800vac**, page 07, box **Turbo pump focal plane detector I260TP**)
-  * Select window **PUMPDOWN STATUS** and click on button **START PUMPDOWN**. The **PUMPDOWN STATUS** and **VENT STATUS** windows should display "PUMPDOWN IN PROGRESS"
-       * The vent valve **I260VV** and foreline valve **I260FV** will be automatically closed
-       * After the rough valve **I260RV** is automatically open, the mechanical pump will start pumping.
-       * The pressures in the mechanical pump (from **I259PG**) and beam chamber (from **I261PG**) will jump momentarily to very high values. They should go down slowly after few seconds (otherwise, the chamber is not properly closed).
-       * Make sure that pressure inside the CRDCs and IC (LabView) decrease at the same rate as the chamber. Otherwise, stop the pump-down sequence immediately.
-       * Note that during the rough pump-down sequence, pressure in the foreline I260PG will increase to few torr due to the purge line connected to the turbo pump. This is ok, as long as the turbo pump is OFF
-       * When pressure in **I261PG** is ~95 mTorr, turn on the chiller providing cooling water to the turbo pump.
-       * When pressure in the chamber (from **I261PG**) gets below 90 mTorr (at least 45 min), **I260RV** will close.
-       * Open the foreline valve **I260FV** using PanelMate box **Foreline vlve I260FV ** and clicking "Open"
-       * When pressure in the foreline (**I260PG**) is below 200 mTorr, turn on the turbo pump. You will see the speed increasing in the PanelMate box **I260TP speed**
-       * It takes about 8 min to get the turbo pump "At Speed" (as read in box **Turbo pump focal plane detector I260TP**). During that time, the pressure in the focal-plane chamber will slowly increase (it is not being pump down) by few mTorr
-       * When the turbo pump is "At Speed" and pressure in the chamber (as read in **I261PG**) is below 175 mTorr, the turbo-pump gate valve **I260GV** will open
-       * After **I260GV** gets opened, you will see a pressure spike in the foreline **I260PG** up to ~1 Torr. This is normal behavior. This pressure will slowly decrease below 200 mTorr in about 2 minutes. It will take at least 30 min to reach the nominal value (~60 mTorr).
-  * Wait for few hours until vacuum is good. You can then turn on the ion gauge **I264IG**

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