Lasers and Ultra-precise Timing Injector Laser and Commissioning Ultra-precise timing
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Lasers and Ultra-precise Timing Injector Laser and Commissioning Injector Laser review Commissioning Experience Updates to transport and controls Hand-off to operations Ultra-precise timing LBNL Collaboration Status NEH Laser Status October 29, 2007 Lasers and Ultra-precise Timing 1 Bill White b.white@slac.stanford.edu UV pulse goals • • • IR to UV conversion efficiency > 10 %, 2.5 mJ output @ 255 nm 252-258 nm, < 2% energy stability 120 Hz, MTBF > 5000 hours Spatial Profile FWHM = 1.2 – 3.0 mm Temporal Profile FWHM = 10 ps (5-20 ps) flat-top, < 8% peak-to peak October 29, 2007 Lasers and Ultra-precise Timing 90-10 rise and fall times < 1 ps 2 Bill White b.white@slac.stanford.edu Transport Vacuum cell ZoomLaser Bay L4 Beam shaper L3 L1 L2 Table in the tunnel Virtual Cathode Camera Photocathode Powermeter Transport tube Steering system L5 Polarizer Waveplate Shutter Launch System L6 October 29, 2007 Lasers and Ultra-precise Timing 3 Bill White b.white@slac.stanford.edu Active Steering Stabilization Accomplishments •Great Up Time! •20 weeks of commissioning •Three 8 hour downs – Hot swappable parts will be here before next run •One 3 hour down – my fault •2 hours per week for locking problems •98% up time •Solved spatial flutter problem – further improvement expected •>500 mJ on Cathode – spec was 250 •<1.5% rms stability – spec was 2% October 29, 2007 Lasers and Ultra-precise Timing 4 Bill White b.white@slac.stanford.edu Commissioning Issues Transport Tubes 10m long Hydro-carbons coating and damaging inside of windows when exposed to UV Dust inside tube settling on inside of windows – Damage and diffraction Will go to less expensive windows and on site pump so the windows can be replaced more quickly. Tubes cleaned last week October 29, 2007 Lasers and Ultra-precise Timing 5 Bill White b.white@slac.stanford.edu Commissioning Issues Oscillator Problems Picomotor translation stage instability Femtolase will replace Coarse control currently disabled/manual Phase ambiguity due to locking at 476MHz Impacts phasing of RF This oscillator does not self start mode-locking or RF locking Femtolase will replace this oscillator with an all new unit that should address all of these issues October 29, 2007 Lasers and Ultra-precise Timing 6 Bill White b.white@slac.stanford.edu New master oscillator from Femtolasers • Narrower bandwidth requested to have higher spectral intensity and get a better seeding in the Regen (before FWHM = 30 nm) • Crystal is sealed in airtight cavity to avoid contamination (no more weekly cleaning, endurance test made during 200 hours) • Remote starting capability October 29, 2007 Lasers and Ultra-precise Timing 7 Bill White b.white@slac.stanford.edu New Femtolock driver for the oscillator • Oscillator is first locked to 119 MHz and then to 476 MHz : no more 476 MHz bucket ambiguity. • Lock button added to be lock always on the same bucket. • RF- locking loop and lock button can be run remotely. October 29, 2007 Lasers and Ultra-precise Timing 8 Bill White b.white@slac.stanford.edu Jedi Pump Laser Failure of Q-switch driver We diagnosed. Thales rushed a board and technician to us. 3 Days lost Various chiller problems Now have local source of spares Began purchasing spares in November CR Delayed order placement Should receive in August Hot swappable spares operational Spare Jedis are installed and October 29, 2007 Lasers and Ultra-precise Timing 9 Bill White b.white@slac.stanford.edu Commissioning Issues Streak Camera October 29, 2007 Lasers and Ultra-precise Timing Cross correlator 10 Bill White b.white@slac.stanford.edu Temporal Pulse Shaping The achieved temporal pulse shape meets physics requirements for the injector commissioning Plan to improve the temporal shape Replace the Lyot filter in the regen amplifier by the edge mirrors – this will reduce oscillations Continue working on the Dazzler settings and the optimum UV conversion crystals lengths Thales engineers are coming back in September to continue working on shaping Plan B – to use stacking of Gaussian pulses Design and parts for pulse stacking are in place October 29, 2007 Lasers and Ultra-precise Timing 11 Bill White b.white@slac.stanford.edu Temporal Pulse Shape - Now October 29, 2007 Lasers and Ultra-precise Timing 12 Bill White b.white@slac.stanford.edu Commissioning Issues Newport aspheric telescope Converts Gaussian to flat-top GBS-UV H Requires good Gaussian input Very sensitive to alignment Aperture is just as good and much simpler to align Allows flexibility Simplifies overall transport October 29, 2007 Lasers and Ultra-precise Timing 13 Bill White b.white@slac.stanford.edu New Transport Layout October 29, 2007 Lasers and Ultra-precise Timing 14 Bill White b.white@slac.stanford.edu Option of Focusing the Beam on the Cathode Removable Lens LDave F=3m L4 F4=F5=5000 Z-adjustment of L6 changes the beam size on the cathode F6=1500 Table in the tunnel Transport tube Steering system L5 Photocathode Shutter L6 October 29, 2007 Lasers and Ultra-precise Timing 15 Active Steering Stabilization LDave Bill White b.white@slac.stanford.edu No Major Changes to Vault Transport C2 M4 L5 Cathode Cleaning Lens M5 L6 C1 VC UV plates for Cameras M3 M2 Power Meter M1 Cathode October 29, 2007 Lasers and Ultra-precise Timing 16 Bill White b.white@slac.stanford.edu Spares We do not have a complete hot swappable laser system. Two Spare Jedis, power supplies and chillers have been received and installed Millenia pump laser and spare chiller has been received and installed We believe all long lead items that could fail are now covered with spares October 29, 2007 Lasers and Ultra-precise Timing 17 Bill White b.white@slac.stanford.edu Future - Hand Over to Ops Now Develop procedures for laser Automate things that can and need to be automated August 07 Down Train Operations Group on typical Operation Procedures Hand off laser by Jan 08 Laser Group will support Ops Scheduled Maintenance Issues that arise outside of the typical operation envelope October 29, 2007 Lasers and Ultra-precise Timing 18 Bill White b.white@slac.stanford.edu Normal Operations The daily operation of the laser which, with the new transport system and oscillator, will be controlled from MCC. This will be the responsibility of the Accelerator Operations Department. Training of the operators, documented operating procedures as appropriate, and support during the transition will be the responsibility of the Laser Group. Operating procedures and documentation must conform to the document control policies of the Accelerator Operations Department. The Laser Group is responsible for ensuring that engineered protection systems are in place to ensure the safety of personnel and the protection of the equipment. October 29, 2007 Lasers and Ultra-precise Timing 19 Bill White b.white@slac.stanford.edu Daily or Shift-wise Parameter Logging: The Laser Group is responsible for developing control-system based facilities and software to monitor and record laser parameters as needed to support the efficient operation and maintenance of the laser systems. These facilities will function automatically as much as possible; however, some logging activities may require operator intervention on a daily or shift-by-shift basis. The Accelerator Operations Department staff will work with the Laser Group to develop efficient ways to achieve this. October 29, 2007 Lasers and Ultra-precise Timing 20 Bill White b.white@slac.stanford.edu Scheduled Maintenance: Maintenance of the laser and associated equipment will be the responsibility of the Laser Group who will work with the Accelerator Operations Department to develop policies and procedures that work for both groups, within the established ASD framework for coordinating accelerator maintenance activities. October 29, 2007 Lasers and Ultra-precise Timing 21 Bill White b.white@slac.stanford.edu Unscheduled Problems: This will be the responsibility of the Laser Group who will designate someone on call during commissioning shifts. The Laser Group will also provide the Accelerator Operations Department with a pager number and/or call list to expedite contact with a qualified laser person when a problem arises whenever the laser systems are scheduled to be operated. The information will be provided in the form of one or more pages that can be incorporated directly into the ASD Call-In Lists binder. October 29, 2007 Lasers and Ultra-precise Timing 22 Bill White b.white@slac.stanford.edu LCLS High Precision Timing SLAC/LBNL collaboration to develop system for high precision (<100 fsec) delivery of timing reference from RFPC laser to X-ray Endstations. SLAC/LBNL MoU signed and project goals and responsibilities specified 30 month project with Aug 07 start with ~$2.1M budget for LBNL LBNL project team assembled. SLAC contacts identified. Conceptual design review planned for late Nov.-early Dec. 07 October 29, 2007 Lasers and Ultra-precise Timing 23 Bill White b.white@slac.stanford.edu Development Status reference 2.8GHz CW fiber laser signal delay AM 2km fiber freq. shifter feedforward corrector phase delay control • • Transmission of S-band master oscillator over optically stabilized fiber shows <40 fsec stability over 24 hours using feedforward correction for group/phase velocity dispersion. • Still tracking down systematic effects with possible improvement System now installed in chassis for tests in SLAC tunnel October 29, 2007 Lasers and Ultra-precise Timing 24 network analyzer (phase) 36fs RMS stable output group error as fiber heats 1.6% correction added Bill White b.white@slac.stanford.edu RF transmission design Design of final timing system in progress. Procurement of components in progress. October 29, 2007 Lasers and Ultra-precise Timing 25 Bill White b.white@slac.stanford.edu Three main phases Timing Plans Phase I Stabilize an optical fiber in SLAC tunnel and klystron gallery using already built LBNL hardware. Goal is to understand relative thermo-acoustic environment. Hardware returns to LBNL after test. Transmit RF over stabilized fiber in loopback mode (i.e. loop fiber back to source). Perform attenuation vs. time measurements of fiber to look at radiation damage effects. Phase 2 Build core of LCLS timing stabilization hardware provide digitally controlled GVD correction engineer digitally controlled transmitter and receiver develop system diagnostics provide basic connectivity to LCLS controls Install and test at LCLS Phase 3 Specify (LBNL), procure and install (SLAC) fiber for final timing Deliver, install, and test final LCLS timing system (4 stabilized fiber lines, expandable to 16) full system diagnostics and controls full connectivity to LCLS controls October 29, 2007 Lasers and Ultra-precise Timing 26 Bill White b.white@slac.stanford.edu The NEH has a centralized laser bay which transports beams to 3 experimental hutches Near Experiment Hall Laser Bay Floor Laser Hall LCLS X-ray Beam October 29, 2007 Lasers and Ultra-precise Timing To Far Hall 27 Bill White b.white@slac.stanford.edu The 3 experimental hutches are located one floor below the laser bay Laser Sub-Basement of Near Experiment Hall Bay Transport Tubes Hutch 1 AMO LUSI XPP October 29, 2007 Lasers and Ultra-precise Timing 28 Bill White b.white@slac.stanford.edu Near Hall Lasers NEH LSS design underway PDR held on Oct. 18 ESD and SOP next October 29, 2007 Lasers and Ultra-precise Timing 29 Bill White b.white@slac.stanford.edu Main Control of the LSS is in the Laser Hall LSS Status Sign Door Interlocks LSS Control Panel Door Interlocks Laser Bay Badge Reader Door Bypass Transport Shutters Crash Panel LASER OFF October 29, 2007 Lasers and Ultra-precise Timing LSS Status Sign 30 Bill White b.white@slac.stanford.edu Near Hall Lasers NEH LSS design underway PDR held on Oct. 18 ESD and SOP next AMO Laser PRD coming soon Purchased for delivery in October 08 LUSI XPP Laser Will use AMO laser for initial experiments Dedicated laser in 2011 or 2012 Interface with XPP has been defined, interface document soon. October 29, 2007 Lasers and Ultra-precise Timing 31 Bill White b.white@slac.stanford.edu Summary Injector laser Modifications for automation underway Procedures under development Hand-off begins January Spares are here Precision Timing Project is finally officially underway Prototype will be tested during next run NEH Lasers LSS design underway Laser procurement process beginning now Receive laser in October 08 October 29, 2007 Lasers and Ultra-precise Timing 32 Bill White b.white@slac.stanford.edu End October 29, 2007 Lasers and Ultra-precise Timing 33 Bill White b.white@slac.stanford.edu
