LLE Annual Report
The fiscal year ending September 2015 (FY15) concluded the first 30 months of the fourth five-year renewal of Cooperative Agreement DE-NA0001944 with the U.S. Department of Energy (DOE). This annual report summarizes work carried out under the Cooperative Agreement at the Laboratory for Laser Energetics (LLE) during the past fiscal year including work on the Inertial Confinement Fusion (ICF) Campaign; laser, optical materials, and advanced technology development; operation of the Omega Laser Facility for the ICF and High-Energy-Density (HED) Campaigns, the National Laser Users' Facility (NLUF), the Laboratory Basic Science (LBS) Program, and other external users; and programs focusing on the education of high school, undergraduate, and graduate students during the year.
Inertial Confinement Fusion Research
One of LLE's principal missions is to conduct research in ICF with particular emphasis on supporting the goal of achieving ignition at the National Ignition Facility (NIF). This program uses the Omega Laser Facility and the full experimental, theoretical, and engineering resources of the laboratory. During FY15, a record 2116 target shots were taken at the Omega Laser Facility (comprised of the 60-beam OMEGA UV laser and the four-beam, high-energy petawatt OMEGA EP laser). Over 70% of the facility's target shots in FY15 were carried out for ICF and HED campaigns.
LLE plays a lead role in validating the performance of cryogenic target implosions, essential to all forms of ICF ignition. LLE is responsible for a number of critical elements within the Integrated Experimental Teams that support the demonstration of indirect-drive ignition on the NIF and is the lead laboratory for the validation of the polar-direct-drive (PDD) approach to ignition on the NIF. LLE has also developed, tested, and constructed a number of diagnostics that are being used at both the Omega Laser Facility and the NIF. During this past year, progress in the Inertial Fusion Research Program continued in three principal areas: ICF experiments and experiments in support of ICF; theoretical analysis and design efforts aimed at improving direct-drive–ignition capsule designs (including polar-direct-drive–ignition designs) and advanced ignition concepts such as shock ignition and fast ignition; and development of diagnostics for experiments on the NIF, OMEGA, and OMEGA EP.
Lasers, Optical Materials, and Advanced Technology
The Laboratory's efforts in the development of advanced high-power lasers and optical materials in support of its inertial fusion and HED research programs is also covered in this volume, including mechanical characterization of optical oxide thin films, investigations of thermal fluctuations in hybrid superconductor/ferromagnetic bilayers and nanostripes, characterization of the macrostructure of chemical-vapor–deposited zinc sulfide substrates, measurements of the temporal contrast of a white-light–seeded noncollinear optical parametric amplifier, computational chemistry modeling and the design of photoswitchable alignment materials for optically addressable liquid crystal devices, studies of the magnetorheological finishing (MRF) of single-crystal and chemical-vapor–deposited polycrystalline zinc sulfide, and single-shot, high-resolution characterization of optical pulses by spectral phase diversity.
FY15 Omega Facility Operations
During FY15, the Omega Laser Facility conducted 1380 target shots on OMEGA and 736 target shots on OMEGA EP for a total of 2116 target shots [see Tables 144.XII and 144.XIII (p. 212)].
OMEGA averaged 11.5 target shots per operating day with Availability and Experimental Effectiveness averages of 94.5% and 93.5%, respectively.
OMEGA EP was operated extensively for a variety of internal and external users. A total of 736 target shots were taken into the OMEGA EP target chamber and 43 joint target shots were taken into the OMEGA target chamber. OMEGA EP averaged 7.8 target shots per operating day with Availability and Experimental Effectiveness averages of 95.3% and 95.8% respectively.
Per the guidance provided by DOE/NNSA (National Nuclear Security Administration), the facility provided target shots for the ICF, HED, NLUF, and LBS programs. The facility also provided a small number of shots for Commissariat á l'énergie atomique et aux energies alternatives (CEA) and for the Defense Threat Reduction Agency (DTRA) (see Fig. 1). Over 70% of the target shots in FY15 were taken for the ICF and HED programs.
National Laser Users' Facility and External Users Programs
The fundamental science campaigns accounted for ~24% of the shots taken in FY15. Nearly half of these shots were dedicated to university fundamental science under the NLUF Program, and the remaining shots were allotted to the LBS Program, comprising peer-reviewed fundamental science experiments conducted by the national laboratories and by LLE, including the Fusion Science Center (FSC).
The Omega Laser Facility was also used for several campaigns by teams from CEA of France.
The facility users during this year included 13 collaborative teams participating in the NLUF Program; 14 teams led by Lawrence Livermore National Laboratory (LLNL) and LLE scientists participating in the LBS Program; many collaborative teams from the national laboratories conducting ICF experiments; investigators from LLNL, Los Alamos National Laboratory (LANL), and Sandia National Laboratories (SNL) conducting experiments for high-energy-density-physics programs; and scientists and engineers from CEA.
Omega Laser Facility Users Group (OLUG)
A capacity gathering of 110 researchers from around the world met at LLE for the Seventh Omega Laser Facility Users Group (OLUG) workshop to facilitate communications and exchanges among individual Omega users, and between users and the LLE management; to present ongoing and proposed research; to encourage research opportunities and collaborations that could be undertaken at the Omega Laser Facility and in a complementary fashion at other facilities [such as the NIF or the Laboratoire pour l'Utilisation des Lasers Intenses (LULI)]; to provide an opportunity for students, postdoctoral fellows, and young researchers to present their research in an informal setting; and to provide feedback from the users to LLE management about ways to improve and keep the facility and future experimental campaigns at the cutting edge.
As the only major university participant in the National ICF Program, education continues as an important mission for LLE. The Laboratory's education programs cover the range from high school to graduate education.
The high school program involved 12 students chosen from Rochester-area high schools. The projects were related to current research activities at LLE and covered a broad range of areas of interest including laser physics, computational modeling of implosion physics, experimental diagnostics development, liquid crystal chemistry, ultra-intense laser–matter interactions, optical design, tritium capture and storage, and interactive data analysis.
Forty-one undergraduate students participated in work or research projects at LLE this past year. Student projects include operational maintenance of the Omega Laser Facility; work in laser development, materials, and optical thin-film coating laboratories; computer programming; image processing; and diagnostics development. This is a unique opportunity for students, many of whom will go on to pursue a higher degree in the area in which they gained experience at LLE.
In FY15, 60 graduate students were involved in research projects at LLE, and LLE directly sponsored 35 students pursuing Ph.D. degrees via the NNSA-supported Frank Horton Fellowship Program in Laser Energetics. Their research includes theoretical and experimental plasma physics, HED physics, x-ray and atomic physics, nuclear fusion, ultrafast optoelectronics, high-power laser development and applications, nonlinear optics, optical materials and optical fabrication technology, and target fabrication. In addition, LLE directly funded research programs within the MIT Plasma Science and Fusion Center, the State University of New York (SUNY) at Geneseo, and the University of Wisconsin.
Table of Contents
- Direct Observation of the Two-Plasmon-Decay Common Plasma Wave Using Ultraviolet Thomson Scattering
- Measurements of the Conduction Zone Length and Mass Ablation Rate in Cryogenic Direct-Drive Implosions on OMEGA
- Polar-Direct-Drive Experiments at the National Ignition Facility
- Impact of First-Principles Properties of Deuterium–Tritiumon Inertial Confinement Fusion Target Designs
- Spherical Strong-Shock Generation for Shock-Ignition Inertial Fusion
- Tritium Migration to the Surfaces of Aluminum 6061,Oxygen-Free, High-Conductivity Copper, and Stainless-Steel 316
- Alpha Heating and Burning Plasmas in Inertial Confinement Fusion
- Measurements of the Ablation-Front Trajectory and Low-Mode Nonuniformity in Direct-Drive Implosions Using X-Ray Self-Emission Shadowgraphy
- Nanomechanical Properties of Single-Layer Optical Oxide Thin Films Used for High-Laser-Damage-Threshold Applications
- Thermal Fluctuations in Superconductor/Ferromagnet Nanostripes
- Spectral Changes Induced by a Phase Modulator Acting as a Time Lens
- Surface-Texture Evolution of Different Chemical-Vapor–Deposited Zinc Sulfide Flats Polished with Various Magnetorheological Fluids
- First-Principles Equation of State of Polystyrene and Its Effect on Inertial Confinement Fusion Implosions
- Hydrodynamic Scaling of the Deceleration-Phase Rayleigh–Taylor Instability
- Shock-Wave Equation-of-State Measurements in Fused Silica up to 1600 GPa
- Temporal-Contrast Measurements of a White-Light–Seeded Noncollinear Optical Parametric Amplifier
- Computational Chemistry Modeling and Design of Photoswitchable Alignment Materials for Optically Addressable Liquid Crystal Devices
- The Temporal Analog of Reflection and Refraction of Optical Beams
- Ultrahigh Responsivity of Optically Active, Semiconducting Asymmetric Nanochannel Diodes
- The Hydrogen Isotope Separation System
- Single-Shot High-Resolution Characterization of Optical Pulses by Spectral Phase Diversity
- Magnetorheological Finishing of Chemical-Vapor–Deposited Zinc Sulfide via Chemically and Mechanically Modified Fluids
- Interferometric Strain Measurements with a Fiber-Optic Probe
- The Seventh Omega Laser Facility Users Group Workshop
- LLE's Summer High School Research Program
- FY15 Laser Facility Report
- National Laser Users' Facility and External Users' Programs
- Publications and Conference Presentations