Mark Tillack, John Pulsifer, Joel Hollingsworth, S. S. Harilal Final Optic Fabrication, Testing and...
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Transcript of Mark Tillack, John Pulsifer, Joel Hollingsworth, S. S. Harilal Final Optic Fabrication, Testing and...
![Page 1: Mark Tillack, John Pulsifer, Joel Hollingsworth, S. S. Harilal Final Optic Fabrication, Testing and System Integration HAPL Project Meeting San Diego,](https://reader030.fdocuments.in/reader030/viewer/2022032612/56649eb25503460f94bb82de/html5/thumbnails/1.jpg)
Mark Tillack, John Pulsifer, Joel Hollingsworth, S. S.
Harilal
Final Optic Fabrication, Testing and System Integration
HAPL Project MeetingSan Diego, CA
8-9 August 2006
With contributions from: Bill Goodman (Schafer Corp.), Hesham Khater
(LLNL), Colin Ophus and Dave Mitlin (U. Alberta)
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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
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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
polarizepulse slice300 mJ150 mJKD*P50 mJ15 mJCompex laser“pseudo-ISI”10 mJ35 mJ150 mJ
“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)
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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
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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
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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) reproducibilit
y
• Facility improvements have made data more reproducible
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Grain size effects on pure Al are obscured by variations in fabrication
techniques
BachAlumiplat
e
Schafer
• Evaporative coating was attempted because smaller grains should result in a stronger surface (y= o ky/d1/2)
• 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
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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 pitsCabot
Microelectronics is supporting this work with substantial IR&D support
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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, SNLAVelomir Radmilovic, LBNLDave Mitlin, U. AlbertaColin Ophus, U. Alberta
Hall-Petch and solid solution hardening regime
Amorphous/nano-crystalline regime
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Al-16%Mo and Al-24%Mo were fabricated and tested
• Beautiful, specular thick film
Si substrateAlMo (16%)gradient from AlMo to pure AlAl capping layertAlMotAltgrad10 nm
100 nm5 m
Possible solution:
• Low conductivity and increased absorption: poor performance
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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
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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 irradiationsThree 22-day cycles 5.4 FPY dose
8 mmTest optic50 mm
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: 1015
n/cm2/s>1 MeV: 6x1014
n/cm2/s• Power plant:
>0.1 MeV: ~1013 n/cm2/s
>1 MeV: ~1013 n/cm2/s
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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 108 shots
• Radiation damage testing
– Finish planning
– Obtain specimens
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