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Meeting thin film design and production challenges for laser damage resistant optical coatings at the Sandia Large Optics Coating Operation

Proceedings of SPIE - The International Society for Optical Engineering

Bellum, John; Kletecka, Damon; Rambo, Patrick K.; Smith, Ian C.; Kimmel, Mark W.; Schwarz, Jens S.; Geissel, Matthias; Copeland, Guild; Atherton, B.W.; Smith, Douglas; Smith, Ian C.; Khripin, Constantine

Sandia's Large Optics Coating Operation provides laser damage resistant optical coatings on meter-class optics required for the ZBacklighter Terawatt and Petawatt lasers. Deposition is by electron beam evaporation in a 2.3 m x 2.3 m x 1.8 m temperature controlled vacuum chamber. Ion assisted deposition (IAD) is optional. Coating types range from antireflection (AR) to high reflection (HR) at S and P polarizations for angle of incidence (AOI) from 0° to 47°. This paper reports progress in meeting challenges in design and deposition of these high laser induced damage threshold (LIDT) coatings. Numerous LIDT tests (NIF-MEL protocol, 3.5 ns laser pulses at 1064 nm and 532 nm) on the coatings confirm that they are robust against laser damage. Typical LIDTs are: at 1064 nm, 45° AOI, Ppol, 79 J/cm2 (IAD 32 layer HR coating) and 73 J/cm2 (non-IAD 32 layer HR coating); at 1064 nm, 32° AOI, 82 J/cm2 (Ppol) and 55 J/cm2 (Spol ) (non-IAD 32 layer HR coating); and at 532 nm, Ppol, 16 J/cm2 (25° AOI) and 19 J/cm2 (45° AOI) (IAD 50 layer HR coating). The demands of meeting challenging spectral, AOI and LIDT performances are highlighted by an HR coating required to provide R > 99.6% reflectivity in Ppol and Spol over AOIs from 24° to 47° within ∼ 1% bandwidth at both 527 nm and 1054 nm. Another issue is coating surface roughness. For IAD of HR coatings, elevating the chamber temperature to ∼ 120°C and turning the ion beam off during the pause in deposition between layers reduce the coating surface roughness compared to runs at lower temperatures with the ion beam on continuously. Atomic force microscopy and optical profilometry confirm the reduced surface roughness for these IAD coatings, and tests show that their LIDTs remain high. © 2009 Copyright SPIE - The International Society for Optical Engineering.

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Fill-Tube-Induced Mass Perturbations on X-Ray-Driven, Ignition-Scale, Inertial-Confinement-Fusion Capsule Shells and the Implications for Ignition Experiments

Physical Review Letters

Bennett, Guy R.; Keller, Keith L.; Mulville, Thomas D.; Peterson, Kyle J.; Sinars, Daniel S.; Smith, Ian C.; Vesey, Roger A.; Herrmann, Mark H.; Christenson, Peggy J.; Cuneo, M.E.

We present on the first inertial-confinement-fusion ignition facility, the target capsule will be DT filled through a long, narrow tube inserted into the shell. μg-scale shell perturbations Δm' arising from multiple, 10–50 μm-diameter, hollow SiO2 tubes on x-ray-driven, ignition-scale, 1-mg capsules have been measured on a subignition device. Finally, simulations compare well with observation, whence it is corroborated that Δm' arises from early x-ray shadowing by the tube rather than tube mass coupling to the shell, and inferred that 10–20 μm tubes will negligibly affect fusion yield on a full-ignition facility.

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Z-Beamlet: a multi-KJ TW-class laser for backlit x-radiography applications on the Z-Accelerator

Atherton, B.W.; Gonzales, Rita A.; Gurrieri, Thomas G.; Herrmann, Mark H.; Mulville, Thomas D.; Neely, Kelly A.; Rambo, Patrick K.; Rovang, Dean C.; Ruggles, Larry R.; Smith, Ian C.; Schwarz, Jens S.; Simpson, Walter W.; Sinars, Daniel S.; Speas, Christopher S.; Tafoya-Porras, Belinda T.; Wenger, D.F.; Young, Ralph W.; Adams, Richard G.; Bennett, Guy R.; Campbell, David V.; Carroll, Malcolm; Claus, Liam D.; Edens, Aaron E.; Geissel, Matthias G.

Abstract not provided.

X-ray optics on the Z-Accelerator backlit with the Z-Beamlet Laser & Z-Petawatt Laser systems

Gonzales, Rita A.; Gurrieri, Thomas G.; Herrmann, Mark H.; Mulville, Thomas D.; Neely, Kelly A.; Rambo, Patrick K.; Rovang, Dean C.; Ruggles, Larry R.; Schwarz, Jens S.; Adams, Richard G.; Simpson, Walter W.; Sinars, Daniel S.; Smith, Ian C.; Speas, Christopher S.; Tafoya-Porras, Belinda T.; Wenger, D.F.; Young, Ralph W.; Edens, Aaron E.; Atherton, B.W.; Bennett, Guy R.; Campbell, David V.; Carroll, Malcolm; Claus, Liam D.; Geissel, Matthias G.

Abstract not provided.

1- and 2-frame monochromatic x-ray imaging of NIF-like capsules on Z and future higher-energy higher-resolution 2- & 4-frame x-radiography plans for ZR

Bennett, Guy R.; Campbell, David V.; Claus, Liam D.; Foresi, James S.; Johnson, Drew J.; Jones, Michael J.; Keller, Keith L.; Leifeste, Gordon T.; McPherson, Leroy A.; Mulville, Thomas D.; Neely, Kelly A.; Sinars, Daniel S.; Herrmann, Mark H.; Rambo, Patrick K.; Rovang, Dean C.; Ruggles, Larry R.; Simpson, Walter W.; Speas, Christopher S.; Wenger, D.F.; Smith, Ian C.; Cuneo, M.E.; Adams, Richard G.; Atherton, B.W.; Barnard, Wilson J.; Beutler, David E.; Burr, Robert A.

Abstract not provided.

Simple temporal pulse shaping using two Pockels cells

Optical Engineering

Schwarz, Jens; Rambo, Patrick K.; Smith, Ian C.; Porter, John

We use two Pockels cells in series to achieve simple temporal pulse shaping. This technique is used in our optical parametric chirp pulse amplification (OPCPA) system to optimize the temporal shape of the pump pulse. It also offers a low cost alternative to arbitrary waveform generators. © 2005 Society of Photo-Optical Instrumentation Engineers.

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Results 151–175 of 183
Results 151–175 of 183