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Preparation for tuning
ELECTRONICS, PATCH PANELS, AND HARDWARE data-U6 (south end)
Electronic location: two racks that contain all the electronics and patch panels. Oscilloscope TEKSCOPE11 Use: S800 detector/timing diagnostics Location: left rack on shelf below I3 beamstop control NMR Oscilloscopes Use: NMR resonances display Location: upper two shelves on right electronics rack NIM bin Location: below NMR scopes in right electronics racks Use: Canberra HV supply for Object scintillator Upper patch panels (top of left rack) Cables 1-10: to object (not connected in vault; maybe these go to an old target location in the transfer hall) Cables 11-20: to object Cables 21-25: to intermediate image box Cable 26 is missing Cable 27-50 should go to pivot point (mostly not connect in vault) Middle patch panel (top of left rack) Cables 51-70: to S800 FP SHV cables 1-2: to object SHV cables 6-10: should go to intermediate image box (apparently not connected in vault) SHV cables 11-20: to pivot point (not connected in vault)
S800 FP (top level of S3 vault)
Electronics location: two racks “East” and “West” facing each other on top level of S3 vault on south side of FP Patch panels: SHV Cables 21-30: to Data-U6 dangling at location of old S800 FP electronics under FP Cables 51-70: to Data-U6 Cables 91-110: to pivot point
Pivot point (bottom level of S3 vault)
Electronics location: one rack on bottom level of S3 vault on south side of final analysis line triplet near stairs to middle level Patch panels Cables 75-110: to Data-U6 Cables 70-80: to object Cables 81-90: to intermediate image Cables 91-110: to S800 FP
Intermediate Image (accessed via middle level of S3 vault)
Electronics location: one rack above intermediate image box located on west end of top level of S3 vault Patch panels (in electronics rack on top level of S3 vault) Cables 21-25: to Data-U6 Cables 81-90: to pivot point
Object position (access via middle level of S3 vault)
Electronics location: under first triplet in analysis line Patch panels (mounted on object box support under object box) Cables 11-20: to Data-U6 Cables 71-80: to pivot point SHV cables 1-2: to Data-U6
DETECTOR GAS HANDLING SYSTEM
General Information Required controls and monitoring
LabView gas handling system application PanelMate S800vac.MT2 page 07: Focal Plane Detector
The gas handling systems for both Focal Plane gas-filled detectors – the Ion Chamber and the CRDCs – are remotely controlled via a single LabView application running on the computer S800FP-PC in the S3 vault. This computer can be accessed remotely via the devop1 computer in Data-U6. 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
LabView Control Program To start the gas handling system control application, click on the LabView icon FPGHS_TCPIP_Corrected_V01 on the S800FP-PC desktop.
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 “test”) as the name of the log file and save in file
intranet/files/departments/operations/s800/TO_BE_SPECIFIED 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 xxx) 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. Figure 1: Gas Handling System LabView running remotelly in S800FP-PC Preparation of Gas bottles In Data-U6 Ensure I265GV is closed to isolate focal plane vacuum chamber from the rest of the beamline 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 In the S3 vault Ensure that the gas handling system roughing pump is running and has a good vacuum The pump sits on the floor under the focal plane behind the south support post (PICTURE GOES HERE) The display unit for the pressure at the pump has a needle indicator and is mounted under the focal plane on the south support post (PICTURE GOES HERE) Ensure that the main valves on the gas bottles are open Ensure that the gas bottles are not empty The gas regulators are not normally adjusted. They should all be set to provide a pressure around 20 psi. The bottle supplying the P-10 gas for the ion chamber is secured to the cross-brace of the south support for the focal plane chamber. It has an electronic Ashcroft pressure gauge upstream of the regulator (toggle on and off with the “on/off” switch) and a mechanical pressure gauge downstream of the regulator. (PICTURE GOES HERE) The bottle supplying CF4 (tetrafluoromethane) gas for the CRDCs is secured to the cross-brace of the south support for the focal plane chamber. It has an electronic Ashcroft pressure gauge upstream of the regulator (toggle on and off with the “on/off” switch) and a mechanical pressure gauge downstream of the regulator. (PICTURE GOES HERE) The bottle supplying isobutane (C4H10) for the CRDCs is secured to the south support post for the focal plane chamber. It sits on a scale for monitoring the isobutane consumption – the electronic display for the scale sits on the chiller unit under the focal plane chamber. It has a mechanical pressure gauge downstream of the regulator. (PICTURE GOES HERE) Filling Ion Chamber with Gas Follow instructions under PREPARATION FOR FILLING DETECTORS WITH GAS above Monitor the pressure of the focal plane vacuum chamber (as read out via the I264IG ion gauge) while detectors are being filled with gas; the pressure normally stays below 5E-5 Torr. Confirm that the detector pressure as indicated by the display labeled P.T. #1 reads below a couple of Torr To zero this display: Click on the Slot 3 (PT1) tab to access the details page for PT #1 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 Open valve 2; the flow reading at MFC #1 should jump momentarily 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/regulation 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 PREPARATIONS FOR FILLING DETECTORS WITH GAS above Monitor the pressure of the focal plane vacuum chamber (as read out via the I264IG ion gauge) while detectors are being filled with gas; the pressure normally stays below 5E-5 Torr. 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 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/regulation 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 Gas from Focal Plane Detectors Monitor the pressure of the focal plane vacuum chamber (as read out via the I264IG ion gauge) 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: 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 9 and 25 Close valves 8 and 24 Open valves 6 and 22 Enter vault and close main valves on gas bottles: P-10 for Ion Chamber isobutane (C4H10) and CF4 (tetrafluoromethane) for CRDCs DETECTOR BIAS CONTROL (under development) General Information The TPPACs, the Ion Chamber, and the CRDCs have ISEG power supplies run through a single VME-based bias control. The computer interface for this bias control, the S800 Detector HV Control, is typically run on the devop1 computer in Data-U6 and is started by clicking on S800 HV under the Operations option on the taskbar. The Object scintillator and the FP Scintillator are each controlled separately as described below under the sections for each detector. Object Scintillator The bias for the object scintillator is controlled via the Canberra HV supply located in the left rack in Data-U6 in the NIM bin just underneath the NMR scopes. FP Scintillators Only the fist two scintillators are typically used since in most cases particles do not reach beyond the second detector. The biases for the anode and the drift electrode are each controlled separately via the S800 Detector HV Control. To protect the scintillator PMT bases from damage from discharge under poor vacuum conditions (for example, during a window break on one of the nearby gas detectors), the 12-Volt supply for the PMT bases is interlocked to switch off if the pressure in the focal plane box rises above some minimum value as read by an ion gauge. The ion gauge controller (a black box with an LED digital display) is mounted on the south support structure for the focal plane chamber. The interlock condition is communicated to the PMT bias supply via a multi-pin “D” connector on the back of the controller. If the ion gauge is off, the interlock condition prevents biasing of the scintillator. It is possible to manually override the interlock condition for testing by connecting a “cheater” connector in place of the ion gauge controller to the cable for the interlock. Ion Chamber The biases for the anode and the drift electrode are each controlled separately via the S800 Detector HV Control. Parts of this detector rely on the same 12-Volt power supply used to power the bases of the FP Scintillator PMTs. If the vacuum-based interlock condition for protecting the FP Scintillator PMTs is triggered, the 12-Volt power supply will not be available for the Ion Chamber. CRDCs Each of the two detectors, CRDC1 and CRDC2, has a separate bias control for the anode and the drift electrode via the S800 Detector HV Control. TPPACs The bias of each of the two detectors, PPAC1 and PPAC2 is controlled individually via the S800 Detector HV Control. There are two types of detectors used for the TPPACs: either the “classic” PPACs or PPACs with individual strip readouts for handling higher rates. There is not a difference between the two detector types in terms of how the data is used. They do differ in terms of electronics and acquisition. NMRs CONTROL (under development) Two digital oscilloscopes are dedicated to NMR readout – one for the analysis line NMRs and one for the spectrograph NMRs The scopes are located __ and are isolated from clean ground because this signals from the NMR probes are on a dirty ground TURNING S800 MAGNETS ON/OFF (under development) The powering of the S800 magnets needs to follow three steps: Arming of Dump Switch The power supply for each of the spectrograph dipoles has a dump switch that must be armed to send current through the dipoles. The dump switch is in place to protect the conductors inside the cryostat from melting in the event that the magnet becomes non-superconducting while energized with high current. When triggered, a dump switch provides a high-current short circuit path to dump the energy from the magnet. The kinds of error conditions that will trigger the dump switches are the same conditions that trip off power supplies to other superconducting magnets on the beamlines. Examples include: a lead drop fault error, a quench detection (read and set values not agreeing over a period of time), a cryogenic error condition (e.g., a low helium level or blown rupture disk), and a loss in flow of cooling water for the power supplies. While designed to protect the magnet from a more expensive repair if the magnet quenches when energized, it is possible that the dump switch can get damaged if triggered because of the large amount of energy involved. Therefore, the magnet should be ramped down before any planned trigger conditions occur. The Dump Switches of the two S800 dipoles are located in second level of S3 (see picture xxx). In order to arm the switches .xxxxx Set S800 magnets currents to values of running setting Open the Panel Mate screen THallps Turn on S800 magnets by clicking in the box with the corresponding name (e.g. I228DS), followed by a click in the ON box. (Go through pages xxx to cover all magnets.) Go to page xxx and select the steering magnets: ONLY THE S800, xxxxxx. Note that some of the power supplies are connected to more than one steering magnet. If necessary, disable the steering magnet of the other line and enable the correct one. Load setting: Open Barney Select S3, followed by S800 (see picture) For each of the three segments (segments 6, 7 and 8), enter value of magnetic rigidity and click on the button Set setting (see picture) PREPARATION FOR TUNING In S3 vault Arm dump switches Make sure object ion gauge is off Go to page xx on Panel Mate xxx. Check status xxx Ensure viewer is ready Make sure gas bottles for FP detectors are open Make sure Intermediate PPACs have gas In data-U Start Software tools PanelMates NMR GUIs Barney Labview Gas Handling System Controls Labview Bias Controls Alarm servers and monitors Linux HV controls (alarm server should be started first) SpecTcl (alart server should be started first) Run Control (in coordination with experimenters) Trigger Control GUI (in coordination with experimenters) Scalers (in coordination with experimenters) Put 10 Amps in Spectrograph dipoles Start gas in detectors Refer to Section xx (S800 Focal Plane Gas Handling System Operation) Enable crad04 with a rate limit of 20 kHz (crad04 looks at E1 up) If it does not interfere with experimenter preparation (see “Unreacted Beam” section below) Set spectrograph Brho Start scalers
