scholarly journals Characterization Of Physically Vapor Deposited Af2400 Thin Films

1993 ◽  
Vol 328 ◽  
Author(s):  
R. Chow ◽  
M. K. Spragge ◽  
G. E. Loomis ◽  
F. Rainer ◽  
R. L. Ward ◽  
...  
Keyword(s):  
Refractive Index ◽  
Morphological Changes ◽  
Amorphous Polymer ◽  
Lawrence Livermore National Laboratory ◽  
National Laboratory ◽  
Fused Silica ◽  
Deposition Parameters ◽  
Temperature Scanning ◽  
Normal Laboratory

ABSTRACTAnti-reflective optical coatings made with Teflon AF2400 had the highest laser damage thresholds recorded for physical vapor deposited coatings at the Lawrence Livermore National Laboratory damage facility. Physical vapor deposited layers of Teflon AF2400, a perfluorinated amorphous polymer, Maintained the bulk optical properties of a high transmittance from 200 nm to 1200 nm, and a low refractive index. In addition, the refractive index can be intentionally reduced by control of two common deposition parameters, deposition rate and substrate temperature. Scanning electron microscopy and nuclear magnetic resonance observations indicated that morphological changes caused the variations in the refractive index rather than compositional changes. The coatings adhered to fused silica and silicon wafers under normal laboratory handling conditions.

Characterization of the Corrosion Behavior of Alloy 22 after Five Years Immersion in Multi-ionic Solutions

2002 ◽  
Vol 757 ◽  
Author(s):  
Lana L. Wong ◽  
David V. Fix ◽  
John C. Estill ◽  
R. Daniel McCright ◽  
Raúl B. Rebak
Keyword(s):  
Lawrence Livermore National Laboratory ◽  
National Laboratory ◽  
Electrolyte Solutions ◽  
Underground Water ◽  
Localized Corrosion ◽  
General Corrosion ◽  
Uniform Corrosion ◽  
Waste Container ◽  
Alloy 22

ABSTRACTAlloy 22 (N06022) is the candidate material for the corrosion resistant, outer barrier of the nuclear waste container. Two of the potential corrosion degradation modes of the container are uniform corrosion and localized corrosion. A testing program is under way at the Lawrence Livermore National Laboratory to determine the susceptibility of Alloy 22 to these two forms of corrosion using immersion tests. Metallic coupons are being exposed to several electrolyte solutions simulating concentrated underground water from pH 3 to 10 at 60°C and 90°C. This paper describes the results obtained after more than a five-year exposure of 122 specimens to the testing electrolyte solutions. Results show little general corrosion and the absence of localized corrosion. The maximum general corrosion rate was 23 nm/yr.

scholarly journals Characterization of B and N Implanted Fused Silica

1989 ◽  
Vol 157 ◽  
Author(s):  
G. W. Arnold ◽  
R. K. Brow ◽  
M. J. Carr ◽  
J. C. Barbour
Keyword(s):  
Refractive Index ◽  
Oxygen Vacancy ◽  
Optoelectronic Devices ◽  
Fused Silica ◽  
Vacancy Defects ◽  
Implantation Damage

ABSTRACTThe implantation of B and N into fused silica can result in chemical incorporation into the glass with a consequent larger increase in refractive index than is possible due to volume compaction alone. B implantation produces anomalously large concentrations of oxygen-vacancy defects which aid in the establishment of B into a borosilicate layer. N implants can result in unreacted N accumulations in addition to N incorporated into a Si-oxynitride layer. The unreacted N can also be incorporated by implantation damage (e.g., Si, Ar, Kr)--before or after N implantation--which provides additional occupancy sites. These results are important with respect to the use of implantation-produced waveguides for optoelectronic devices.

Microcharacterization of Defects Induced in Fused Silica by High Power 3ω UV (355nm) Laser Pulses

2001 ◽  
Vol 7 (S2) ◽  
pp. 496-497
Author(s):  
Marion A. Stevens-Kalceff ◽  
Joe Wong ◽  
Andre Stesmans
Keyword(s):  
High Power ◽  
Lawrence Livermore National Laboratory ◽  
National Laboratory ◽  
Fused Silica ◽  
Mitigation Strategies ◽  
Powerful Laser ◽  
Fusion Reactions ◽  
Damage Initiation ◽  
Essential Components ◽  
Induced Defects

There are many technical challenges to be overcome before controlled fusion reactions can be achieved. The National Ignition Facility (NIF) at Lawrence Livermore National Laboratory is being developed to initiate fusion reactions using the world's most powerful laser. Essential components of the Facility are the ultra pure silica (SiO2) lenses that focus the powerful laser beams on to the target. Irradiation with a high power laser has been observed to damage the silica lenses, resulting in the formation of defects. The ensuing degradation of the lens performance necessitates its replacement. It is therefore critical to characterize the induced defects and understand the laser damage initiation and evolution, so that damage mitigation strategies can be developed.Cathodoluminescence (CL) microscopy and spectroscopy enables high spatial resolution and high sensitivity detection of defects in poorly conducting materials. It is therefore an ideal microanalytical technique with which to study laser irradiation-induced defects.

scholarly journals Characterization of short-pulse laser-produced plasmas at the Lawrence Livermore National Laboratory ultrashort-pulse laser

1993 ◽  
Author(s):  
Ronnie L. Shepherd ◽  
Dwight F. Price ◽  
William E. White ◽  
Albert L. Osterheld ◽  
Rosemary S. Walling ◽  
...  
Keyword(s):  
Pulse Laser ◽  
Ultrashort Pulse ◽  
Short Pulse ◽  
Lawrence Livermore National Laboratory ◽  
National Laboratory ◽  
Ultrashort Pulse Laser ◽  
Short Pulse Laser

Characterization of a Plutonium-Bearing Zirconolite-Rich Synroc

1996 ◽  
Vol 465 ◽  
Author(s):  
E. C. Buck ◽  
B. Ebbinghaus ◽  
A. J. Bakel ◽  
J. K. Bates
Keyword(s):  
Oxidation State ◽  
Nuclear Weapons ◽  
Lawrence Livermore National Laboratory ◽  
National Laboratory ◽  
Argonne National Laboratory ◽  
Waste Form ◽  
Ceramic Waste

ABSTRACTA titanate-based ceramic waste form, rich in phases structurally related to zirconolite (CaZrTi2O7), is being developed as a possible method for immobilizing excess plutonium from dismantled nuclear weapons. As part of this program, Lawrence Livermore National Laboratory (LLNL) produced several ceramics that were then characterized at Argonne National Laboratory (ANL). The plutonium-loaded ceramic was found to contain a Pu-Gd zirconolite phase but also contained plutonium titanates, Gd-polymignyte, and a series of other phases. In addition, much of the Pu was remained as PuO2-x. The Pu oxidation state in the zirconolite was determined to be mainly Pu4+, although some Pu3+ was believed to be present.

TEM characterization of proton-exchanged LiNbO3 optical waveguides

1986 ◽  
Vol 44 ◽  
pp. 480-481
Author(s):  
W. E. Lee
Keyword(s):  
Refractive Index ◽  
Benzoic Acid ◽  
Optical Waveguides ◽  
Total Internal Reflection ◽  
Index Of Refraction ◽  
Optical Measurements ◽  
Lithium Ions ◽  
Wide Channel ◽  
Tem Characterization

An optical waveguide consists of a several-micron wide channel with a slightly different index of refraction than the host substrate; light can be trapped in the channel by total internal reflection.Optical waveguides can be formed from single-crystal LiNbO3 using the proton exhange technique. In this technique, polished specimens are masked with polycrystal1ine chromium in such a way as to leave 3-13 μm wide channels. These are held in benzoic acid at 249°C for 5 minutes allowing protons to exchange for lithium ions within the channels causing an increase in the refractive index of the channel and creating the waveguide. Unfortunately, optical measurements often reveal a loss in waveguiding ability up to several weeks after exchange.

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