bill white lasers and ultra-precise [email protected] october 29, 2007 1 lasers and...
Post on 20-Jan-2016
227 views
TRANSCRIPT
Bill White
Lasers and Ultra-precise Timing [email protected]
October 29, 20071
Lasers and Ultra-precise Timing
Injector Laser and CommissioningInjector Laser review
Commissioning Experience
Updates to transport and controls
Hand-off to operations
Ultra-precise timingLBNL Collaboration
Status
NEH Laser Status
Bill White
Lasers and Ultra-precise Timing [email protected]
October 29, 20072
UV pulse goals
90-10 rise and fall times < 1 psflat-top, < 8% peak-to peak
• 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 ProfileFWHM = 10 ps(5-20 ps)
Bill White
Lasers and Ultra-precise Timing [email protected]
October 29, 20073
Transport Laser Bay
Launch System
Beam shaper
Vacuum cell Zoom
Transport tube
Table in the
tunnel
Photocathode
Virtual Cathode
Steering system
Active Steering
Stabilization
L1
L2
L3
L4
L5
L6
Waveplate
Polarizer
Powermeter
Camera
Shutter
Bill White
Lasers and Ultra-precise Timing [email protected]
October 29, 20074
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 J on Cathode – spec was 250
•<1.5% rms stability – spec was 2%
Bill White
Lasers and Ultra-precise Timing [email protected]
October 29, 20075
Commissioning IssuesTransport 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
Bill White
Lasers and Ultra-precise Timing [email protected]
October 29, 20076
Commissioning Issues
Oscillator ProblemsPicomotor 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
Bill White
Lasers and Ultra-precise Timing [email protected]
October 29, 20077
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
Bill White
Lasers and Ultra-precise Timing [email protected]
October 29, 20078
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.
Bill White
Lasers and Ultra-precise Timing [email protected]
October 29, 20079
Jedi Pump Laser
Failure of Q-switch driverWe diagnosed.Thales rushed a board and technician to us.3 Days lost
Various chiller problemsNow have local source of spares
Began purchasing spares in November
CR Delayed order placementShould receive in AugustHot swappable spares
Spare Jedis are installed and operational
Bill White
Lasers and Ultra-precise Timing [email protected]
October 29, 200710
Commissioning Issues
Cross correlatorStreak Camera
Bill White
Lasers and Ultra-precise Timing [email protected]
October 29, 200711
Temporal Pulse Shaping
The achieved temporal pulse shape meets physics requirements for the injector commissioningPlan to improve the temporal shape
Replace the Lyot filter in the regen amplifier by the edge mirrors – this will reduce oscillationsContinue working on the Dazzler settings and the optimum UV conversion crystals lengthsThales engineers are coming back in September to continue working on shaping
Plan B – to use stacking of Gaussian pulsesDesign and parts for pulse stacking are in place
Bill White
Lasers and Ultra-precise Timing [email protected]
October 29, 200712
Temporal Pulse Shape - Now
Bill White
Lasers and Ultra-precise Timing [email protected]
October 29, 200713
GBS-UV H
Commissioning IssuesNewport aspheric telescope
Converts Gaussian to flat-top
Requires good Gaussian input
Very sensitive to alignment
Aperture is just as good and much simpler to align
Allows flexibilitySimplifies overall transport
Bill White
Lasers and Ultra-precise Timing [email protected]
October 29, 200714
Beam
Attenu
ator
Pulse Stacker
Iris Wheel
Zoom Telescope
Insertable
Power Meter
Insertable
Power Meter
Active Steering
Stabilization
New Transport Layout
UV BeamOutput
Vacuum Tube
to Gun
Bill White
Lasers and Ultra-precise Timing [email protected]
October 29, 200715
Option of Focusing the Beam on the Cathode
Transport tube
Table in the
tunnel
Photocathode
Steering system
Active Steering
Stabilization
F4=F5=5000
F6=1500
L4
L5
L6Shutter
LDave
Removable Lens LDave F=3m
Z-adjustment of L6 changes the beam size on the cathode
Bill White
Lasers and Ultra-precise Timing [email protected]
October 29, 200716
No Major Changes to Vault Transport
M5
L5
M4
L6 M3
M2
VC Power Meter
Cathode
M1
C1
C2 UV plates for Cameras
Cathode Cleaning Lens
Bill White
Lasers and Ultra-precise Timing [email protected]
October 29, 200717
SparesWe do not have a complete hot swappable laser system.Two Spare Jedis, power supplies and chillers have been received and installedMillenia pump laser and spare chiller has been received and installedWe believe all long lead items that could fail are now covered with spares
Bill White
Lasers and Ultra-precise Timing [email protected]
October 29, 200718
Future - Hand Over to Ops
NowDevelop procedures for laserAutomate things that can and need to be automated
August 07 DownTrain Operations Group on typical Operation ProceduresHand off laser by Jan 08
Laser Group will support Ops Scheduled MaintenanceIssues that arise outside of the typical operation envelope
Bill White
Lasers and Ultra-precise Timing [email protected]
October 29, 200719
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.
Bill White
Lasers and Ultra-precise Timing [email protected]
October 29, 200720
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.
Bill White
Lasers and Ultra-precise Timing [email protected]
October 29, 200721
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.
Bill White
Lasers and Ultra-precise Timing [email protected]
October 29, 200722
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.
Bill White
Lasers and Ultra-precise Timing [email protected]
October 29, 200723
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
Bill White
Lasers and Ultra-precise Timing [email protected]
October 29, 200724
Development Status
• 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
CWfiberlaser
freq.shifter
delayAM
phase delay control
networkanalyzer(phase)
reference
signal
2kmfiber
2.8GHz
feed-forwardcorrector
stableoutput
group error asfiber heats
1.6% correction added
36fsRMS
Bill White
Lasers and Ultra-precise Timing [email protected]
October 29, 200725
RF transmission design
Design of final timing system in progress.
Procurement of components in progress.
Bill White
Lasers and Ultra-precise Timing [email protected]
October 29, 200726
Timing PlansThree main phasesPhase 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 2Build 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 3Specify (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
Bill White
Lasers and Ultra-precise Timing [email protected]
October 29, 200727
The NEH has a centralized laser bay which transports beams to 3 experimental hutches
Near Experiment Hall Laser Bay Floor
Laser HallLCLS X-ray
BeamTo Far Hall
Bill White
Lasers and Ultra-precise Timing [email protected]
October 29, 200728
The 3 experimental hutches are located one floor below the laser bay
Laser Bay
Transport TubesHutch 1
AMO
LUSI XPP
Sub-Basement of Near Experiment Hall
Bill White
Lasers and Ultra-precise Timing [email protected]
October 29, 200729
Near Hall Lasers
NEH LSS design underwayPDR held on Oct. 18
ESD and SOP next
Bill White
Lasers and Ultra-precise Timing [email protected]
October 29, 200730
Main Control of the LSS is in the Laser Hall
Laser BayLSS Control
Panel
Door Interlocks
LSS Status Sign
LSS Status Sign
Cra
sh
Pa
ne
l
Transport Shutters
LASER OFF
Door Bypass
Badge Reader
Door Interlocks
Bill White
Lasers and Ultra-precise Timing [email protected]
October 29, 200731
Near Hall LasersNEH LSS design underway
PDR held on Oct. 18ESD and SOP next
AMO LaserPRD coming soonPurchased for delivery in October 08
LUSI XPP Laser Will use AMO laser for initial experimentsDedicated laser in 2011 or 2012Interface with XPP has been defined, interface document soon.
Bill White
Lasers and Ultra-precise Timing [email protected]
October 29, 200732
SummaryInjector laser
Modifications for automation underwayProcedures under developmentHand-off begins JanuarySpares are here
Precision TimingProject is finally officially underwayPrototype will be tested during next run
NEH Lasers LSS design underwayLaser procurement process beginning nowReceive laser in October 08