The National Ignition Facility Wavefront Requirements and Optical Architecture

The National Ignition Facility Wavefront Requirements and Optical Architecture PDF Author:
Publisher:
ISBN:
Category :
Languages : en
Pages : 32

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Book Description
With the first four of its eventual 192 beams now executing shots and generating more than 100 kilojoules of laser energy at its primary wavelength of 1.06 [mu]m, the National Ignition Facility (NIF) at the Lawrence Livermore National Laboratory is already the world's largest and most energetic laser. The optical system performance requirements that are in place for NIF are derived from the goals of the missions it is designed to serve. These missions include inertial confinement fusion (ICF) research and the study of matter at extreme energy densities and pressures. These mission requirements have led to a design strategy for achieving high quality focusable energy and power from the laser and to specifications on optics that are important for an ICF laser. The design of NIF utilizes a multipass architecture with a single large amplifier type that provides high gain, high extraction efficiency and high packing density. We have taken a systems engineering approach to the practical implementation of this design that specifies the wavefront parameters of individual optics in order to achieve the desired cumulative performance of the laser beamline. This presentation provides a detailed look at the causes and effects of performance degradation in large laser systems and how NIF has been designed to overcome these effects. We will also present results of spot size performance measurements that have validated many of the early design decisions that have been incorporated in the NIF laser architecture.

The National Ignition Facility Wavefront Requirements and Optical Architecture

The National Ignition Facility Wavefront Requirements and Optical Architecture PDF Author:
Publisher:
ISBN:
Category :
Languages : en
Pages : 32

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Book Description
With the first four of its eventual 192 beams now executing shots and generating more than 100 kilojoules of laser energy at its primary wavelength of 1.06 [mu]m, the National Ignition Facility (NIF) at the Lawrence Livermore National Laboratory is already the world's largest and most energetic laser. The optical system performance requirements that are in place for NIF are derived from the goals of the missions it is designed to serve. These missions include inertial confinement fusion (ICF) research and the study of matter at extreme energy densities and pressures. These mission requirements have led to a design strategy for achieving high quality focusable energy and power from the laser and to specifications on optics that are important for an ICF laser. The design of NIF utilizes a multipass architecture with a single large amplifier type that provides high gain, high extraction efficiency and high packing density. We have taken a systems engineering approach to the practical implementation of this design that specifies the wavefront parameters of individual optics in order to achieve the desired cumulative performance of the laser beamline. This presentation provides a detailed look at the causes and effects of performance degradation in large laser systems and how NIF has been designed to overcome these effects. We will also present results of spot size performance measurements that have validated many of the early design decisions that have been incorporated in the NIF laser architecture.

Optical Engineering at the Lawrence Livermore National Laboratory II

Optical Engineering at the Lawrence Livermore National Laboratory II PDF Author: Monya A. Lane
Publisher: SPIE-International Society for Optical Engineering
ISBN:
Category : Political Science
Languages : en
Pages : 206

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Book Description
Proceedings of SPIE present the original research papers presented at SPIE conferences and other high-quality conferences in the broad-ranging fields of optics and photonics. These books provide prompt access to the latest innovations in research and technology in their respective fields. Proceedings of SPIE are among the most cited references in patent literature.

Meyers Taschenlexikon

Meyers Taschenlexikon PDF Author:
Publisher:
ISBN:
Category : Encyclopedias and dictionaries, German
Languages : en
Pages :

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The Wavefront Control System for the National Ignition Facility

The Wavefront Control System for the National Ignition Facility PDF Author:
Publisher:
ISBN:
Category :
Languages : en
Pages :

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Book Description
The National Ignition Facility (NIF) requires that pulses from each of the 192 laser beams be positioned on target with an accuracy of 50 [mu]m rms. Beam quality must be sufficient to focus a total of 1.8 MJ of 0.351-[mu]m light into a 600-[mu]m-diameter volume. An optimally flat beam wavefront can achieve this pointing and focusing accuracy. The control system corrects wavefront aberrations by performing closed-loop compensation during laser alignment to correct for gas density variations. Static compensation of flashlamp-induced thermal distortion is established just prior to the laser shot. The control system compensates each laser beam at 10 Hz by measuring the wavefront with a 77-lenslet Hartmann sensor and applying corrections with a 39-actuator deformable mirror. The distributed architecture utilizes SPARC AXi computers running Solaris to perform real-time image processing of sensor data and PowerPC-based computers running VxWorks to compute mirror commands. A single pair of SPARC and PowerPC processors accomplishes wavefront control for a group of eight beams. The software design uses proven adaptive optic control algorithms that are implemented in a multi-tasking environment to economically control the beam wavefronts in parallel. Prototype tests have achieved a closed-loop residual error of 0.03 waves rms. aberrations, the spot size requirement and goal could not be met without a wavefront control system.

National Ignition Facility Design, Performance, and Cost

National Ignition Facility Design, Performance, and Cost PDF Author:
Publisher:
ISBN:
Category :
Languages : en
Pages : 12

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Book Description
A conceptual design for the National Ignition Facility (NIF) has been completed and its cost has been estimated by a multilaboratory team. To maximize the performance/cost ratio a compact, segmented amplifier is used in a multipass architecture. Many recent optical and laser technology developments have been incorporated into the final design. The Beamlet project has successfully demonstrated the new concept. The mission of ICF Program using the NEF is to achieve ignition and gain in the laboratory. The facility will be used for defense applications such as weapons physics and weapons effects experiments, and for civilian applications such as inertial fusion energy development and fundamental studies of matter at high energy density.

The Origin and Evolution of the Optics Specifications for the National Ignition Facility

The Origin and Evolution of the Optics Specifications for the National Ignition Facility PDF Author:
Publisher:
ISBN:
Category :
Languages : en
Pages : 12

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Book Description
In the second half of the 1990's, LLNL and others will be designing and beginning construction of the National Ignition Facility (NIF). At more than 10 times the power and size of the Nova laser system, this new laser will be capable of producing the worlds first controlled fusion ignition and burn, completing a vital milestone on the path to Fusion Energy. In order to optimize the performance of the laser system for a minimum cost, the designers have been conducting a campaign to properly specify the optical properties of the more than 7,500 large optical components to be deployed in the NIF. The draft optics specifications derived from this effort will be presented. The evolution of these specifications, both in language and in content, will be discussed, specifically transmitted wavefront (both P-V and PSD), scratch/dig, surface roughness, bubbles and inclusions specifications.

Review of the Department of Energy's Inertial Confinement Fusion Program

Review of the Department of Energy's Inertial Confinement Fusion Program PDF Author: National Research Council
Publisher: National Academies Press
ISBN: 0309057787
Category : Science
Languages : en
Pages : 63

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Book Description


Verschiedene Drucksachen betreffend Ernen

Verschiedene Drucksachen betreffend Ernen PDF Author:
Publisher:
ISBN:
Category :
Languages : en
Pages :

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The National Ignition Facility

The National Ignition Facility PDF Author:
Publisher:
ISBN:
Category :
Languages : en
Pages : 11

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Book Description
The National Ignition Facility (NIF), a 192-beam fusion laser, is presently under construction at the Lawrence Livermore National Laboratory with an expected completion in 2008. The facility contains 7,456 meter-scale optics for amplification, beam steering, vacuum barriers, focusing, polarization rotation, and wavelength conversion. A multiphase program was put in place to increase the monthly optical manufacturing rate by up to 20x while simultaneously reducing cost by up to 3x through a sub-scale development, full-scale facilitization, and a pilot production phase. Currently 80% of the optics are complete with over 50% installed. In order to manufacture the high quality optics at desired manufacturing rate of over 100 precision optics per month, new more deterministic advanced fabrication technologies had to be employed over those used to manufacture previous fusion lasers.

Optical Propagation Modeling for the National Ignition Facility

Optical Propagation Modeling for the National Ignition Facility PDF Author:
Publisher:
ISBN:
Category :
Languages : en
Pages :

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Book Description
Optical propagation modeling of the National Ignition Facility has been utilized extensively from conceptual design several years ago through to early operations today. In practice we routinely (for every shot) model beam propagation starting from the waveform generator through to the target. This includes the regenerative amplifier, the 4-pass rod amplifier, and the large slab amplifiers. Such models have been improved over time to include details such as distances between components, gain profiles in the laser slabs and rods, transient optical distortions due to the flashlamp heating of laser slabs, measured transmitted and reflected wavefronts for all large optics, the adaptive optic feedback loop, and the frequency converter. These calculations allow nearfield and farfield predictions in good agreement with measurements.