Mark Tillack, John Pulsifer, Joel Hollingsworth, S. S. Harilal Final Optic Fabrication, Testing and System Integration HAPL Project Meeting San Diego, CA 8-9 August 2006 With contributions from: Bill Goodman (Schafer Corp.), Hesham Khater (LLNL), Colin Ophus and Dave Mitlin (U. Alberta)

1.Improved our simulation capability A KrF oscillator-amplifier configuration was installed and tested Sample scanning and auto shutdown were added 2.Expanded the database on Al coatings (toward end-of-life) More data were obtained on electroplated and e-coated mirrors 3.Developed techniques to fabricate larger optics CMP was tested for post-processing large-area high-quality surfaces 4.Performed component and system integration A substrate assessment was performed (Schafer) Neutron irradiation experiments were planned 5.Explored alternative mirror concepts 4” AlMo mirrors were fabricated in collaboration w/ LBNL and U. Alberta 1.Improved our simulation capability A KrF oscillator-amplifier configuration was installed and tested Sample scanning and auto shutdown were added 2.Expanded the database on Al coatings (toward end-of-life) More data were obtained on electroplated and e-coated mirrors 3.Developed techniques to fabricate larger optics CMP was tested for post-processing large-area high-quality surfaces 4.Performed component and system integration A substrate assessment was performed (Schafer) Neutron irradiation experiments were planned 5.Explored alternative mirror concepts 4” AlMo mirrors were fabricated in collaboration w/ LBNL and U. Alberta 1.Improved our simulation capability A KrF oscillator-amplifier configuration was installed and tested Sample scanning and auto shutdown were added 2.Expanded the database on Al coatings (toward end-of-life) More data were obtained on electroplated and e-coated mirrors 3.Developed techniques to fabricate larger optics CMP was tested for post-processing large-area high-quality surfaces 4.Performed component and system integration A substrate assessment was performed (Schafer) Neutron irradiation experiments were planned 5.Explored alternative mirror concepts 4” AlMo mirrors were fabricated in collaboration w/ LBNL and U. Alberta 1.Improved our simulation capability A KrF oscillator-amplifier configuration was installed and tested Sample scanning and auto shutdown were added 2.Expanded the database on Al coatings (toward end-of-life) More data were obtained on electroplated and e-coated mirrors 3.Developed techniques to fabricate larger optics CMP was tested for post-processing large-area high-quality surfaces 4.Performed component and system integration A substrate assessment was performed (Schafer) Neutron irradiation experiments were planned 5.Explored alternative mirror concepts 4” AlMo mirrors were fabricated in collaboration w/ LBNL and U. Alberta 1.Improved our simulation capability A KrF oscillator-amplifier configuration was installed and tested Sample scanning and auto shutdown were added 2.Expanded the database on Al coatings (toward end-of-life) More data were obtained on electroplated and e-coated mirrors 3.Developed techniques to fabricate larger optics CMP was tested for post-processing large-area high-quality surfaces 4.Performed component and system integration A substrate assessment was performed (Schafer) Neutron irradiation experiments were planned 5.Explored alternative mirror concepts 4” AlMo mirrors were fabricated in collaboration w/ LBNL and U. Alberta Progress was made in 5 areas 2 of 13

Control over beam characteristics required us to add an amplifier Death by 1000 cuts: loss of energy in the Pockels cell was the final straw “Performance improvements to the UCSD mirror test facility using an oscillator - amplifier configuration” S. S. Harilal, J. Pulsifer and M. S. Tillack Gain curve with 5-ns pulse, 20.5 kV Compex, 17 kV LPX Performance is strongly dependent on HV and timing of both lasers (and Pockels cell) 3 of 13

Good news and bad news The good news: the gain curve results in profile smoothing High LPX voltage amplifies residual output from the Pockels cell The bad news: non-linear gain and jitter can distort the temporal profile Jitter allows leakage from latter part of seed Seed pulse 4 of 13

Facility improvements are making life easier, and higher shot-counts possible Automated shutdown enables higher PRF External control of target position allows more data (better statistics) No damage Damage leading to shutdown 5 of 13

We have a lot more data now on diamond-turned Alumiplate “Laser-induced damage testing of metal mirrors: fluence-life data and surface analysis” J. Pulsifer, M. S. Tillack, J. Hollingsworth, L. Carlson PRF effect PRF data are looking promising lifetime Higher shot count data look worse (this may be the limit for Alumiplate) reproducibility Facility improvements have made data more reproducible 6 of 13

Grain size effects on pure Al are obscured by variations in fabrication techniques BachAlumiplate Schafer Evaporative coating was attempted because smaller grains should result in a stronger surface (  y  =  o k y /d 1/2 ) All surfaces were diamond-turned Not all evaporative coatings have smaller grains, and the trend with grain size is not obvious Better control of fabrication processes is essential for continuation of this work 7 of 13

CMP provides us a pathway to high- quality, large-aperture metal mirrors “Fabrication techniques for Al and Al alloy optical coatings for the GIMM” J. Hollingsworth, J. Pulsifer and M. S. Tillack Uses a corrosive slurry with carefully passivated surface Significant advantages over SPDT: – Less “invasive” (thinner coatings) – Time depends on depth, not area – History of semiconductor-level QC <1 nm RMS, 15 nm pits Cabot Microelectronics is supporting this work with substantial IR&D support 8 of 13

A new alloy, AlMo was explored as a high-strength alternative to pure Al 2-gun magnetron sputtered Thick (>5  m) specular coating obtained with no postprocessing Improved mechanical properties Reflectivity & conductivity? Acknowledgements : Thanks to Tim Renk, SNLA Velomir Radmilovic, LBNL Dave Mitlin, U. Alberta Colin Ophus, U. Alberta Hall-Petch and solid solution hardening regime Amorphous/nano- crystalline regime 9 of 13

Al-16%Mo and Al-24%Mo were fabricated and tested Beautiful, specular thick film 10 nm 100 nm 5  m Possible solution: Low conductivity and increased absorption: poor performance 10 of 13

Candidate substrates were evaluated in preparation for radiation testing (1 cm) and prototype (4”) development “Candidate Mirror Technologies for the Grazing Incidence Metal Mirror” Bill Goodman (Schafer Corp.) Candidates:Metrics: Neutronic feasibility –Neutron damage resistance –Purity Manufacturability –Surface figure –Roughness –Coating adhesion –Cooling capability Industrial capability –Available database –R&D needs (risk) –Cost Carbon Based –C-C composite –Carbon fiber reinforced Silicon Carbide –  -SiC (polycrystalline) –Reaction bonded SiC (2-phase, polycrystalline) –  -SiC (CVD, polycrystalline) –  -SiC foam core (CVD/CVI, polycrystalline) Silicon –Silicon foam core (CVD/CVI, polycrystalline) –Czochralski (single crystal) Aluminum & Alloys –AlBeMet® 162 –Al 6061 foam 11 of 13

Neutron irradiations are being planned A key issue for substrates is neutron-induced swelling We plan to test candidate substrates: SiC, Si, AlBeMet, Al-6061 Include Al coatings to measure neutron-induced roughness Measure surface shape and roughness after irradiations Three 22-day cycles  5.4 FPY dose Handling of activated specimens is a major concern. We are performing activation and dose calculations prior to exposure, and will measure dose rates after exposure background level Al-6061 after full exposure HFIR flux: >0.1 MeV: n/cm 2 /s >1 MeV: 6x10 14 n/cm 2 /s Power plant: >0.1 MeV: ~10 13 n/cm 2 /s >1 MeV: ~10 13 n/cm 2 /s 12 of 13

Next-step goals for GIMM R&D Coating-substrate development – Fabricate and test Al on C/Si and Al/Be composites – Continue efforts on coating improvements – Obtain 4” specimens from vendors – Plan test campaigns at Mercury and Electra End-of-life testing – Complete the facility improvements – Perform further studies of rep-rate effects – Acquire data to 10 8 shots Radiation damage testing – Finish planning – Obtain specimens 13 of 13