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in creator/contributor: "Stowers, I. F."

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Development of a plasma retropulse shutter for Shiva and Nova

A plasma shutter is being developed for a Nd:glass laser fusion system which, at an output spatial filter pinhole, produces a plasma of 10/sup 21/ cm/sup -3/ to block target-reflected light from reentering the laser. A pulser using low-inductance capacitors and elastomer dielectric is switched with uv preilluminated railgaps to resistively heat a wire producing a plasma. The plasma generated within a nozzle and configured in a railgun geometry is projected across the optical beam path at 3.9 cm… more

Date: September 26, 1979

Creator: Bradley, L. P.; Orham, E. L.; Stowers, I. F. & Koert, P.

Item Type: Report

Partner: UNT Libraries Government Documents Department

open access

Energy and technology review

Research programs at Lawrence Livermore Laboratories are described. These include: the generation of intense electron beams for military applications; SYNROC, a permanent means of radioactive-waste storage in synthetic rock compounds; and studies of respiration using a positron camera with radioisotopes produced in the 100-MeV electron linear accelerator. (GHT)

Date: December 1, 1981

Creator: Stowers, I. F.; Crawford, R. B.; Esser, M. A. & Neal, E.

Item Type: Report

Partner: UNT Libraries Government Documents Department

open access

Compact 5 x 10/sup 12/ AMP/SEC rail-gun pulser for a laser plasma shutter

We have developed a rail-gun plasma source to produce a plasma of 10/sup 12/cm/sup -3/ particle density and project it with a velocity of 3.9 cm/..mu..s. This device will be used in a output spatial filter of Nova to project a critical density plasma across an optical beam path and block laser retroreflected light. The object of this paper is to describe the design of a pulser appropriate to the Shiva laser fusion facility, and to describe the preliminary design of a higher current prototype pu… more

Date: June 12, 1979

Creator: Bradley, L. P.; Orham, E. L. & Stowers, I. F.

Item Type: Article

Partner: UNT Libraries Government Documents Department

open access

uv preilluminated gas switches

We have designed, built, and characterized uv preilluminated gas switches for a trigger circuit and a low inductance discharge circuit. These switches have been incorporated into a 54 x 76 x 150 cm pulser module to produce a 1 Ma output current rising at 5 x 10/sup 12/ amps/sec with 1 ns jitter. Twenty such modules will be used on the Nova Inertial Confinement Fusion Laser System for plasma retropulse shutters.

Date: June 3, 1980

Creator: Bradley, L. P.; Orham, E. L.; Stowers, I. F. & Braucht, J. R.

Item Type: Article

Partner: UNT Libraries Government Documents Department

open access

Large scale molecular dynamics modeling of materials fabrication processes

An atomistic molecular dynamics model of materials fabrication processes is presented. Several material removal processes are shown to be within the domain of this simulation method. Results are presented for orthogonal cutting of copper and silicon and for crack propagation in silica glass. Both copper and silicon show ductile behavior, but the atomistic mechanisms that allow this behavior are significantly different in the two cases. The copper chip remains crystalline while the silicon chip … more

Date: February 1, 1994

Creator: Belak, J.; Glosli, J. N.; Boercker, D. B. & Stowers, I. F.

Item Type: Article

Partner: UNT Libraries Government Documents Department

open access

Precision and manufacturing at the Lawrence Livermore National Laboratory

Precision Engineering is one of Lawrence Livermore National Laboratory`s core strengths. This paper discusses the past and present current technology transfer efforts of LLNL`s Precision Engineering program and the Livermore Center for Advanced Manufacturing and Productivity (LCAMP). More than a year ago the Precision Machining Commercialization project embodied several successful methods of transferring high technology from the National Laboratories to industry. Currently LCAMP has already dem… more

Date: November 1, 1993

Creator: Saito, T. T.; Wasley, R. J.; Stowers, I. F.; Donaldson, R. R. & Thompson, D. C.

Item Type: Article

Partner: UNT Libraries Government Documents Department

open access

Qualification of Target Chamber Vacuum Systems Cleanliness using Sol-Gel Coatings

This document defines the procedure necessary to qualify the airborne molecular cleanliness (AMC) of vacuum systems (enclosures or large components) that are placed within the National Ignition Facility (NIF) target chamber or are attached to it and communicate with it during vacuum operation. This test is specific to the NIF target chamber because the allowable time dependent rate of rise in the pore filling of a sol-gel coated SAW sensor is based on some nominal change-out time for the dispos… more

Date: January 3, 2006

Creator: Miller, P.; Stowers, I. F. & Ertel, J. R.

Item Type: Report

Partner: UNT Libraries Government Documents Department

open access

Optical cleanliness specifications and cleanliness verification

Optical cleanliness is important to NIF because it results in beam obscuration and scatter losses which occur in the front-end (containing over 20,000 small optics) and the large-aperture portions of the laser (containing 7,300 optics in 192 beamlines). The level of particulate cleanliness necessary for NIF, is similar to the scatter loss due to surface roughness. That is, the scatter loss should not exceed 2.5 x 10{sup {minus}5} per surface. Establishing requirements for optical and structural… more

Date: July 1, 1999

Creator: Stowers, I. F.

Item Type: Article

Partner: UNT Libraries Government Documents Department

open access

The National Ignition Facility Wavefront Requirements and Optical Architecture

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 {micro}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… more

Date: June 3, 2004

Creator: Spaeth, M. L.; Manes, K. R.; Widmayer, C. C.; Williams, W. H.; Whitman, P. K.; Henesian, M. A. et al.

Item Type: Article

Partner: UNT Libraries Government Documents Department

open access

Clean Construction Protocol for the National Ignition Facility Beampath and Utilities

When the stadium-size, National Ignition Facility (NIF) is fully operational at the Lawrence Livermore National Laboratory (LLNL), its 192 laser beams will deliver 1.8 megajoules (500 terawatts) of energy onto a target to create extremely high temperatures and pressures for inertial confinement fusion research. Due to the high-energy-physics requirements of the NIF optical components, the optics and their surrounding beampath as well as the supporting utility systems must be fabricated, cleaned… more

Date: January 4, 2002

Creator: Predmore, R A; VanDoren, D E; Stowers, I. F. & Stephenson, S. A.

Item Type: Article

Partner: UNT Libraries Government Documents Department

open access

Achieving and maintaining cleanliness in NIF amplifiers

Cleanliness measurements made on AMPLAB prototype National Ignition Facility (NIF) laser amplifiers during assembly, cassette transfer, and amplifier operation are summarized. These measurements include particle counts from surface cleanliness assessments using filter swipe techniques and from airborne particle monitoring. Results are compared with similar measurements made on the Beamlet and Nova lasers and in flashlamp test fixtures. Observations of Class 100,000 aerosols after flashlamp firi… more

Date: July 28, 1998

Creator: Burnham, A. K.; Horvath, J. A.; Letts, S. A.; Menapace, J. A. & Stowers, I. F.

Item Type: Article

Partner: UNT Libraries Government Documents Department

open access

Molecular dynamics simulation of mechanical deformation of ultra-thin metal and ceramic films

We present an overview of the molecular dynamics computer simulation method as employed in the study of the mechanical properties of surfaces at the manometer scale. The embedded atom method is used to model a clean metal surface and the bond-order model is used to model ceramic surfaces. The computer experiment consists of the indentation and scraping of a hard diamond-like tool into and across the surface. Results are presented for the (111) surface of copper and silver and for the (100) surf… more

Date: April 1, 1995

Creator: Belak, J.; Glosli, J. N.; Boercker, D. B. & Stowers, I. F.

Item Type: Article

Partner: UNT Libraries Government Documents Department