1. Drive Laser Commissioning Status
Reminder of requirements on Drive Laser
Thales laser
Transport system
Commissioning in three areas
Thales laser and it’s specs
Beam conditioning and transport
Virtual cathode alignment
Lessons learned – remaining issues
Future

2. UV pulse goals
IR to UV conversion efficiency > 10 %, 2.5 mJ 255 nm
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)
90-10 rise and fall times < 1 ps
flat-top, < 8% peak-to peak

3. Thales Laser system Stretcher UV Conversion Dazzler Preamplifier
Compressor
Oscillator
Final Amplifier
Regen

4. Active Steering Stabilization
Transport
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
Laser Bay
Launch System

5. Active Steering StabilizationM6
In order to meet centroid position stability requirement (min 60μm) M6 should be stabilized with 35μrad accuracy
Sensitivity of the mirror mount 7arcsec – 34 μrad
Laser Bay
Transport Tube M4
Table in the tunnel
Camera C2 M5
From Virtual Cathode M3
Camera C1
Steering Stabilization system test is underway M2
To Photocathode

6. Transport System in the Laser Bay
Remotely Controlled Mirror
Lens
Shaper
Beam Size Adjustment
Shaper Input Adjustment
To Transport tube
Laser Output

7. Optical System next to the Photocathode
From Transport tube
Steering Stabilization Camera
Remotely Controlled Mirror
Lens
Virtual Cathode camera
Steering Stabilization Camera
Lead Block
Lens
Remotely Controlled Mirrors
Powermeter
Lead Blocks
Photocathode
In vacuum mirror

8. Transport Commissioning
Shaper
Diagnostics
Characterization
Calibration of diagnostics
GTL Installation
Virtual Cathode

9. Timeline - Laser Commissioning
Laser table and LSS in Vault
Feb 13th – Began taking UV into vault
Feb 23 – GTL installation began
VC March 1 to March 12.
Gun Installation began March 12.
ARR April 4
Beam April 5

10. Commissioning Issues Better Schedule coordination
Too many people all working in small space
Minor problems have widespread impact
Because of shortened laser commissioning, some laser commissioning will continue with injector commissioning

11. Commissioning Issues
Streak Camera
Cross correlator

12. 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

13. Commissioning Issues Newport aspheric telescope GBS-UV H
Converts Gaussian to flat-top
Requires good Gaussian input
Very sensitive to alignment
Aperture is just as good and much simpler to align
Allows flexibility
Simplifies overall transport
GBS-UV H

14. Today

15. 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.

16. 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

17. Jedi Pump Laser Failure of Q-switch driver Various chiller problems
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

18. 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

19. End