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Breakout Session: Controls. Controls Commissioning Experience. LCLS commissioned a new injector with beam AND commissioned a new Control System. From First Beam Advanced Data Acquisition. Measure time-resolved properties of a single bunch
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Breakout Session: Controls Controls Commissioning Experience
LCLS commissioned a new injector with beam AND commissioned a new Control System From First Beam Advanced Data Acquisition Measure time-resolved properties of a single bunch Slice emittance and energy spread – Key parameter for FEL First observed photoelectrons Streaked image from TCAV
Overview • This presentation summarizes which control system components are currently working for the injector commissioning phase • Screen shots from EPICS show functionality of each system • Data from the Elog is shown to illustrate acquisition • Comments on what works and what doesn’t are included • Summary includes lessons learned and what still needs to be done
Beam line graphic used for most GUIse.g. injector vacuum summary
Engineering graphic used for hardware monitoringe.g. gun temperature monitoring
screen New optical fiber Loss monitor Interim MPS working with SLC processor and timing- See S. Norum presentation for New LCLS MPS
Conventional facilities- some systems interfaced to EPICS controls- gun LCW temp feedback working ok at 30 Hz- need to add alarm interface for temperatures, flows etc.
Timing System- see separate, detailed presentation - LCLS Event system and SLC Timing working in consort
PULNIX 8-bit 640x480 120 fps CameraLink Used for centroid feedback Laser SystemsImage Acquisition and Steering Feedback
Magnet Controls - See presentation by K. Luchini- many new systems commissioned- learning curve for standardization software etc.- regulation and readback an issue for some supplies
Gun RF Feedback in Operation - closing the loop between PAD and PAC
RF Phase Scans Data acquired with Matlab Data acquired with SCP Correlation Plot (diagnose a satellite peak from laser)
UniqVision 12 bit, 1.4 MP 15 fps CameraLink RCX Camera link extender over fiber optic Profile monitor - control and diagnostics through EDM screens 100 mm thick YAG:CeCrystal Gun spectrometer YAG Profile Monitor Screen
3-screen OTR Emittance Measurement135 MeV, 200 pC drift drift Screen 1 Screen 2 (waist) Screen 3
Energy spread in BC1 energy chirp at -40° off crest (4.1 mm)/(230 mm) = 1.8% rms. BC Chicane OTR Screen 1 mm thick Al foil
Wire Scanners Direction of motion Based on existing SLAC mechanical design (E. Bong) Y U X Updated EPICS controls interface Pulse-by-pulse compensation of bunch charge and trajectory jitter
Two types of beam size measurement • Profile monitor screens gives complete transverse profile of beam on a single shot • But inserting it in the beam is disruptive to FEL • Wire scanner gives projected X, Y, and U profiles over several consecutive shots • But is minimally invasive • Redundant measurements are good for commissioning
s s y y RF Transverse Deflecting Cavity 30 MW An S-band DLW structure with a TM11 transverse deflecting mode at 2856 MHz 2.4 m Bunch length Absolute calibration T-Cav. On T-Cav. Off T-Cav. On Centroid Y-position sy T-Cav. Off RF Phase
T-Cav. Slice Emittance Measurement Slice up OTR screen image sxslice Reassemble slices X-Emittance of 1 slice Quadrupole strength
T-Cav Slice Energy Spread Measurement Screen at high dispersion location Slice Energy Spread Y T I M E sxslice dEslice X Energy
Beam Position Monitors- see separate presentation from S. Smith
Simultaneous measurement of all BPMs Fitted beam position versus measured yields resolution <2 microns at 400 pC Synchronous Acquisition to measure Resolution S. Smith et al.
Beam Synchronous Acquisition uses Event Definitions– example of Matlab orbit display
Beam Synchronous Acquisition on the SCP side- example of orbit from gun through to end of linac
Motion control-BC1 chicane movers in use- next to be commissioned: wire scanners, collimators
Generic Tools that are working • SCP • Configuration save and restore • EPICS Channel Watcher • Correlation plots • Strip chart tools • Archive Viewer • Alarm handler • Electronic logbook • Matlab for higher level applications
Reorganizing the control room layout Purchasing more workstations Injector commissioning involved 12 or more in the room, so its likely to increase as the linac and undulator systems are commissioned Control Room shared with PEPII operation
Summary and lessons learned • Remarkable commissioning achievement for the control system • Controls commissioning time was squeezed • Planned BC2–linac installation is tight • Improve liaison with mechanical engineering • Learning curve to handle large number of IOCs and the huge number of PVs • e.g. Restoring after a reboot • Large number of Matlab scripts generated by physicists • Controls group is a great TEAM!