Laser Session Issues

1. Laser Session Issues List of proposed strategies remains the same Front-endPower amplifier OPCPA/(Ti:Sa) Ti:Sa OPCPA Mixed glass Entity to build a turn key solution? Two-stages project implementation: Several PW + 2014-2nd stage up to 10PW?

2. Bottlenecks and/or engineering challenges “System independent” issues • Coherent combination • Beam transportation

3. Identified Bottlenecks for OPCPA/Ti:Sa strategy Bottlenecks a) HDT broadband large size gratings b) Pump lasers: general design, SHG crystals, Homogenizers c) Large size Ti:Sa crystals d) HDT broadband HR coating on large size optics Engineering challenges e) OPCPA front-end: Synchronization & Pumps f) Contrast: ASE + pre-pulses g) Back-reflection isolation h) Strehl ratio & adaptive optics OPCPA / Ti:Sa strategy

4. Identified Bottlenecks for OPCPA/Mixed glass strategy Bottlenecks a) Tiled compressor b) Rep. rate & slab cooling Engineering challenges c) Contrast: ASE + pre-pulses d) Strehl ratio & adaptive optics Mixed-glass strategy

5. a) Bottleneck -HDT broadband large size gratings • Present technology limit: shorter than 20 fs • Time-line development: • design: exist at ILE, Fresnel Inst., St-Etienne • demonstrator: not yet – feasibility: 6 months • Potential providers: PGL, JY, LLNL? • Differential budget: 2-3 M€ (more expensive with back-up solution) • Back-up sol.: largest existing gold gratings OPCPA / Ti:Sa strategy

6. b) Bottleneck - Pump lasers • Present technology limit: below 200J • Time-line development: • severaldesigns: Thales, Quantel, Continuum, LLNL,… • demonstrator: available in less than 1 year (fall 2011) • Potential providers: Thales, Quantel, Continuum, LLNL,… • Estimated budget: 8M€ for 800J @527nm • Back-up sol. for SHG: DKDP, Y:COB (if LBO not available) OPCPA / Ti:Sa strategy

7. c) Bottleneck – Large size Ti:Sa crystals • Present technology limit: 15 cm clear aperture making possible up to 5-7 PW@15 fs • Time-line development: 1 year • design: Crystal System Inc • demonstrator: transverse lasing tests end of April 2011 (LOA-LULI) • Potentialproviders: Crystal System, RSA Le Rubis • Budget: 500k€ for R&D and delivery of 2 x 20cm clear aperture crystals - 150 k€ per add. crystals • Back-up sol.: no OPCPA / Ti:Sa strategy

8. d) Bottleneck - HDT broadband HR coating on large size optics, including deformable mirrors • Present technology limit: only metallic coatings after compression (0.15 J/cm²) • Time-line development: • design: proposed by all companies • Deformablemirror demonstrator: already available and in 1 year (after funding) for 20 cm in diameter • Potential providers: CVI, Okamoto, SAGEM, SESO, Cilas,… + Imagine Optics for DM • Potential Budget: ~ 1.3 M€ for R&D includingdelivery of one deformablemirror (200mm in diameter) • Back-up sol.: metallic coatings OPCPA / Ti:Sa strategy

9. e) Engineering challenge – OPCPA front-end: Synchronization & Pumps • Present technology limit: not available • Time-line development: • design: exists at ILE • demonstrator: not yet – available in 6 months • Provider: Apollon • Budget: • Back-up sol.: standard ns-OPCPA pump & electronic synchronization (available from Thales, Continuum, Quantel) OPCPA / Ti:Sa strategy

10. f) Engineering challenge - Contrast: ASE + pre-pulses • Present technology limit: 12 orders of magnitude demonstrated • Time-line development: • severalexistingdesigns: OPCPA, XPW- saturable absorber, plasma mirrors • demonstrator: XPW-saturable absorber measured@10 mJ • Potential providers: Amplitude, Apollon, Thales, etc… • Budget:depends on the choosentechnology • Back-up sol.: plasma mirror if necessary (for solid-state targets interaction) OPCPA / Ti:Sa strategy

11. g) Engineering challenge - Back-reflection isolation • Present technology limit:small size Pockels-cells and Faraday isolators • Time-line development: • design: PEPC and transverse electrodes Pockels-cells • demonstrator:alreadyavailable • Potential providers: • Budget:depending on requirements • Back-up sol.: Comments: SBS-SRS for long pulses; not an issue for fs pulses. No switch existing at that power but could be solved by small angle misalignment OPCPA / Ti:Sa strategy

12. a) Bottleneck - Tiled compressor • Present technology limit: up to 2 kJ / 2 ps at Rochester: good mechanical & thermal stability • Time-line development: • design: 1740 lines/mm by National Energetics • demonstrator: available at 100 fs within 6 months at small scale • Potentialprovider: National Energetics • Estimated budget: few (>5) M€ • Back-up sol.: no Mixed-glass strategy

13. b) Bottleneck: Rep. rate & slab cooling • Present technology limit: 3 shots/hour • Time-line development: • design: exists at National Energetics • demonstrator: 0.1 Hz in September 2011 • Provider: National Energetics • Budget: • Back-up sol.: 3 shots/hour by using deformable mirror Mixed-glass strategy

14. c) Engineering challenge - Contrast: ASE + pre-pulses • Present technology limit: 10-10 at Trident • Time-line development: • several existing designs: OPCPA, XPW- saturable absorber, plasma mirrors • demonstrator: ? • Provider: • Budget: • Back-up sol.: plasma mirror Mixed-glass strategy

15. Shared engineering challenge - Beam transportation • Present technology limit: • Time-line development: • design: • demonstrator: • Potential provider: expertise at NIF, LMJ, Rutherford, etc… • Budget: • Back-up sol.:

16. Shared bottleneck - Coherent beam combining • Present technology limit: ps level + 100’ fs for fiber laser tech. • Time-line development: several years • design: no • demonstrator: no • Potential provider: not identified at that stage • Budget: ? • Back-up sol.: temporal synchronization

17. Laser session issues • List of proposed strategies remains the same Front-endPower amplifier OPCPA/(Ti:Sa) Ti:Sa OPCPA Mixed glass Q: Entity to build a turn key solution? Q: Two-stages project implementation: Several PW + 2014-2nd stage up to 10PW? Q: The two strategies in parallel?

18. Laser session issues Q: Entity to build a turn key solution? Q: Two-stages project implementation: several PW + 2014-2nd stage up to 10PW? Q: The two strategies in parallel? Due to tight timeline, is an immediate contractual engagement with any entity (industrial?) realistic to build a system up to the present tech limit (several PW) ? Risks have to be shared between ELI-NP and the entity. 2 to 3 PW seems to be the upper limit from industrial side. ELI-NP laser team should join the development team. Another place should be identified for development before ELI-NP building availability. No industrial partner is ready today to assume the risk of delivering turn key 10PW A consortium (involving industrial companies to be defined) could be part of the solution. Single stage approach looks possible but the project could be staged in 2 steps, the first one being dedicated to demonstrated technology This two strategies in parallel development would be more costly but possible?

19. Laser session issues / other comments - LLNL can provide only tech not existing elsewhere. - Dual development could be considered if coherent combining is switched into temporal synchronization. - Rep. rate and intensity on target are linked together (0.1 Hz for 10^23W/cm^2, and 1 Hz or more for 10^24 W/cm^2 assuming real-time feedback corrections) - Improvements on contrast, strehl ratio and so on will continue after the 2015deadline!