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in subjects: "Solid State Lasers"

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The multipulse Thomson scattering diagnostic on the DIII-D tokamak

This paper describes the design and operation of a 40-spatial channel Thomson scattering system that uses multiple 20 Hz Nd:YAG lasers to measure the electron temperature and density profiles periodically throughout an entire plasma discharge. Interference filter polychromators disperse the scattered light which is detected by silicon avalanche photodiodes. The measurable temperature range from 10 eV to 20 keV and the minimum detectable density is about 2 {times} 10{sup 18} m{sup {minus}3}. Las… more

Date: September 1, 1991

Creator: Carlstrom, T. N.; Campbell, G. L.; DeBoo, J. C.; Evanko, R. G.; Evans, J.; Greenfield, C. M. et al.

Item Type: Article

Partner: UNT Libraries Government Documents Department

open access

Analysis of valence-electron structures of Y/sub 3/Al/sub 5/O/sub 12/(YAG) and Al/sub 2/O/sub 3/, Cr/sub 2/O/sub 2/ (Ruby), a study of certain properties of these laser materials related to their valence-electron structures

A direct method of determination of the valence-electron structure from its crystal structure has been presented by the writer at XIIth International Congress of Crystallography, at Ottawa, 1981. Here the method is applied to determine the valence-electron structures of Y/sub 3/Al/sub 5/O/sub 12/ (YAG) and Al/sub 2/O/sub 3/, Cr/sub 2/O/sub 3/ (ruby) to see how certain properties of these laser materials are related to their valence-electron structures. The first point observed is the very stron… more

Date: January 1, 1982

Creator: Yu, S. H. & Yu, L. H.

Item Type: Article

Partner: UNT Libraries Government Documents Department

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Electron heating and confinemet measurements in EBT-S using Thomson scattering

Thomson scattering of ruby laser light was used to measure electron temperatures and densities in the ELMO Bumpy Torus-Scale (EBT-S) at Oak Ridge National Laboratory. The measurements were made primarily during May 1980, although some were taken during January 1980. The scattering system, which was designed for very low electron density measurements, features a 14-J ruby laser, a high-throughput spectrometer, and 15% quantum efficiency photomultipliers. The measured electron densities lie in th… more

Date: September 1, 1980

Creator: Bighel, L. & Cobble, J. A.

Item Type: Report

Partner: UNT Libraries Government Documents Department

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RIMS diagnostics for laser desorption/laser ablation

Laser desorption mass spectrometry is a useful method for interrogating materials and events at or near surfaces. Laser desorption/ablation combined with Resonance Ionization Mass Spectrometry (RIMS) provides a powerful tool to obtain information on chemical composition and speciation and, in some cases, internal and translational energy distributions. The application of this technique to the interrogation of materials and interfaces is discussed for several systems, including the analysis of c… more

Date: January 1, 1986

Creator: Apel, E. C.; Nogar, N. S.; Miller, C. M. & Estler, R. C.

Item Type: Article

Partner: UNT Libraries Government Documents Department

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Optical-scattering measurements from 1. 06-. mu. m, 0. 53-. mu. m, and 0. 35-. mu. m laser-heated disk targets

A discussion is presented on scattered light measurements relevant to three of the important parametric instabilities which occur in high intensity laser plasma interactions: stimulated Brillouin scattering (SBS), the two plasmon decay instability (2-..omega../sub pe/), and stimulated Raman scattering (SRS). Most of these experiments were carried out on the ARGUS facility. Its configuration is described for the multiple wavelength experiments, all of which were conducted with one beam illuminat… more

Date: January 1, 1982

Creator: Turner, R. E.; Campbell, E. M.; Phillion, D. W.; Mead, W. C.; Ze, F.; Max, C. et al.

Item Type: Article

Partner: UNT Libraries Government Documents Department

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Requirements and new materials for fusion laser systems

Higher focusable power in neodymium glass fusion lasers can be obtained through the use of new materials with lower nonlinear index (n/sub 2/) and better energy storage capabilities than the presently employed silicate glass. Silicate, phosphate, fluorophosphate, and beryllium fluoride glasses are discussed in terms of fusion laser requirements, particularly those for the proposed Nova laser. Examples of the variation in spectroscopic and optical properties obtainable with compositional changes… more

Date: October 1, 1977

Creator: Stokowski, S. E.; Weber, M. J.; Saroyan, R. A. & Hagen, W. F.

Item Type: Article

Partner: UNT Libraries Government Documents Department

open access

Design and operation of the multipulse Thomson scattering diagnostic on DIII-D

This paper describes the design and operation of a 40 spatial channel Thomson scattering system that uses multiple 20 Hz Nd:YAG lasers to measure the electron temperature and density profiles periodically throughout an entire plasma discharge. As many as eight lasers may be fired alternately for an average measurement frequency of 160 Hz, or they may be fired in rapid succession (< 10 kHz), producing a burst of pulses for measuring transient events. The high spatial resolution (1.3 cm) and wide… more

Date: March 1, 1992

Creator: Carlstrom, T. N.; Campbell, G. L.; DeBoo, J. C.; Evanko, R.; Greenfield, C. M.; Haskovec, J. et al.

Item Type: Article

Partner: UNT Libraries Government Documents Department

open access

High-power pulsed lasers

The ideas that led to the successful construction and operation of large multibeam fusion lasers at the Lawrence Livermore Laboratory are reviewed. These lasers are based on the use of Nd:glass laser materials. However, most of the concepts are applicable to any laser being designed for fusion experimentation. This report is a summary of lectures given by the author at the 20th Scottish University Summer School in Physics, on Laser Plasma Interaction. This report includes basic concepts of the … more

Date: April 2, 1980

Creator: Holzrichter, J.F.

Item Type: Report

Partner: UNT Libraries Government Documents Department

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Synthesis and characterization of a covalently bound self-assembled macrocycle monolayer thin film for nonlinear optical materials

Synthesis and characterization of covalently bound self-assembled, 5,10,15,20-Tetra(4-pyridyl)-21H,23H-porphine monolayer superlattices on various oxide surfaces such as fused silica, glass or silicon are described. The mono-molecular thin film structures are characterized by UV-visible ({lambda}{sub max} = 447 nm) and FTIR-ATR spectroscopy. In addition, X-ray photoelectron spectroscopy and secondary ion mass spectroscopy studies are used to confirm the formation of a self-assembled monolayer o… more

Date: January 1, 1992

Creator: Li, DeQuan; Swanson, B. I.; Robinson, J. M. & Hoffbauer, M. A.

Item Type: Article

Partner: UNT Libraries Government Documents Department

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Performance of Argus as a laser fusion facility

During the fifteen months that the Argus laser facility has been operating we have had two primary goals. These are: (1) to provide focusable, well characterized, high power beams for laser fusion experiments and (2) to further understand the propagation of high power and energy pulses. The propagation experiments have already led to increases in the laser output power and system reliability. Pulses appropriate for advanced targets are shaped to optimize the compression and heating of the targe… more

Date: September 19, 1977

Creator: Speck, D. R.; Simmons, W. W.; Hunt, J. T.; Boyle, M. J.; Rainer, F.; Storm, E. K. et al.

Item Type: Article

Partner: UNT Libraries Government Documents Department

open access

OMEGA: a short-wavelength laser for fusion experiments

The OMEGA, Nd:glass laser facility was constructed for the purpose of investigating the feasibility of direct-drive laser fusion. With 24 beams producing a total energy of 4 kJ or a peak power of 12 TW, OMEGA is capable of nearly uniform illumination of spherical targets. Six of the OMEGA beams have recently been converted to short-wavelength operation (351 nm). In this paper, we discuss details of the system design and performance, with particular emphasis on the frequency-conversion system an… more

Date: January 1, 1983

Creator: Soures, J. M.; Hutchison, R. J.; Jacobs, S. D.; Lund, L. D.; McCrory, R. L. & Richardson, M. C.

Item Type: Article

Partner: UNT Libraries Government Documents Department

open access

Fast optical shutters for Nova, a high power fusion laser

Preliminary design and performance test results for fast optical shutters intended for use in the Nova high power fusion laser system are briefly described. Both an opening shutter to protect the pellet target from amplified spontaneous emission (ASE), and a closing shutter to protect the laser from light reflected back from the target are discussed. Faraday rotators, synchronized by a 400 Hz oscillator, provide an opening shutter mechanism with an opening time of approximately 10 ..mu..s. A pl… more

Date: October 18, 1977

Creator: Bradley, L. P.; Gagnon, W. L. & Carder, B. M.

Item Type: Article

Partner: UNT Libraries Government Documents Department

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25 megajoule energy storage and delivery system for the Shiva laser

A 25 megajoule, 20 kV capacitive energy storage and delivery system has been built and tested for Shiva--a 20 arm, 10 kJ, 20 TW neodymium glass fusion research laser. This system supplies over 3.5 megamperes to xenon flashlamps for optical pumping of the laser amplifier. About 15% of the energy is used to establish magnetic fields within Faraday rotator glass. A digital based control and diagnostics scheme is employed through the entire pulse power system. This scheme utilizes a distributed dig… more

Date: October 18, 1977

Creator: Gagnon, W.L.; Rupert, P. R.; Berkbigler, L.; Carder, B. M.; Gritton, D. G.; Holloway, R. W. et al.

Item Type: Article

Partner: UNT Libraries Government Documents Department

open access

Materials testing using laser energy deposition

A convenient method for determining the elastic constants of materials has been devised using the energy from a Q-switched neodymium-glass laser. Stress waves are induced in materials having circular rod or rectangular bar geometries by the absorption of energy from the laser. The wave transit times through the material are recorded with a piezoelectric transducer. Both dilatation and shear wave velocities are determined in a single test using an ultrasonic technique and these velocities are us… more

Date: December 20, 1977

Creator: Wilcox, W.W. & Calder, C.A.

Item Type: Article

Partner: UNT Libraries Government Documents Department

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Beam transport optics for laser fusion

The performance of large laser systems for laser fusion is limited by self-induced damage to optical components, arising from the interaction of the intense light with the optical materials in the laser system. In the design of the beam transport optics, due consideration must be given to high intensity effects, including self-focusing, surface damage, and internal reflection focusing. The constraints imposed on the design of optical components by these considerations are discussed.

Date: October 1, 1977

Creator: Glass, A.J.

Item Type: Article

Partner: UNT Libraries Government Documents Department

open access

High energy electron spectra from 1. 06. mu. m laser produced plasmas

An electron spectrometer has been modified to measure 1.06 ..mu.. laser produced electrons in the 0.2 to 1.0 MeV range and has been used extensively at the LLL Argus laser facility. We observe a strong correlation between laser pulse width and the amplitude of electron spectral emission from imploded D-T filled microspheres.

Date: November 1, 1977

Creator: Tirsell, K.G. & Catron, H.C.

Item Type: Article

Partner: UNT Libraries Government Documents Department

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Optical design considerations for laser fusion reactors

The plan for the development of commercial inertial confinement fusion (ICF) power plants is discussed, emphasizing the utilization of the unique features of laser fusion to arrive at conceptual designs for reactors and optical systems which minimize the need for advanced materials and techniques requiring expensive test facilities. A conceptual design for a liquid lithium fall reactor is described which successfully deals with the hostile x-ray and neutron environment and promises to last the … more

Date: September 1, 1977

Creator: Monsler, M.J. & Maniscalco, J.A.

Item Type: Article

Partner: UNT Libraries Government Documents Department

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Uniform laser ablative acceleration of targets at 10/sup 14/ W/cm/sup 2/

We present the first detailed investigations of the ablative acceleration of planar targets while simultaneously using high irradiance (10/sup 14/ W/cm/sup 2/), large focal diameters (1 mm) and long laser pulse duration (3 nsec). Included are measurements of target preheat, ablation pressures and uniformity achieved under these conditions. Targets were accelerated to high velocities with velocity profile uniformity approaching that required for high gain pellet implosions.

Date: August 10, 1982

Creator: Obenschain, S. P.; Whitlock, R. R.; McLean, E. A.; Ripin, B. H.; Price, R. H.; Phillion, D. W. et al.

Item Type: Report

Partner: UNT Libraries Government Documents Department

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Pinhole imaging of laser-produced thermonuclear alpha particles

Results of pinhole images of thermonuclear alpha particles generated by exploding pusher targets in the Argus laser facility are reviewed. Recorded images indicate that the reactions occur within a 25 to 30 micron region with twelve micron resolution for ten micron pinholes and thirty micron resolution for twenty-five micron pinholes. These results are in good agreement with LASNEX computer predictions and are confirmed by Zone Plate imaging of the burn conducted by Natale M. Ceglio at LLL. Pla… more

Date: November 1, 1977

Creator: Brooks, K. M.; Ceglio, N. M.; Slivinsky, V. W.; Ahlstrom, H. G.; Storm, E. K.; Kornblum, H. N. et al.

Item Type: Article

Partner: UNT Libraries Government Documents Department

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Optical diagnostics on dense Z-pinch plasmas

A novel point-diffraction'' interferometer has been implemented on the Los Alamos Solid Fiber Z-Pinch experiment. The laser beam is split into two legs after passing through the plasma. The reference leg is filtered with a pin-hole aperture and recombined with the other leg to form an interferogram. This allows compact mounting of the optics and relative ease of alignment. The Z-Pinch experiment employs a pulsed-power generator that delivers up to 700 KA with a 100ns rise-time through a fiber o… more

Date: January 1, 1992

Creator: Riley, R.A. Jr.; Lovberg, R.H.; Shlachter, J.S. & Scudder, D.W.

Item Type: Article

Partner: UNT Libraries Government Documents Department

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Summary of the status of lasers for inertial confinement fusion

Laser systems designed for plasma research are operating in many laboratories throughout the world. The laser performance itself has become reasonably consistant from laboratory to laboratory and the focusing properties of the laser beams are understood. The plasma physics data, obtained with these systems, also appears to be reasonably self-consistant and is of great interest for inertial fusion applications. These lasers are commonly providing output powers of 0.5 > 2 TW, and power densities … more

Date: November 1, 1979

Creator: Holzrichter, J.F.

Item Type: Report

Partner: UNT Libraries Government Documents Department

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Broad-band soft x-ray diagnostic instruments at the LLNL Novette laser facility

Complementary broad-band instruments have been developed to measure time dependent, absolute soft x-ray spectra at the Lawrence Livermore National Laboratory (LLNL) Nd glass laser irradiation facilities. Absolute flux measurements of x rays emitted from laser-produced plasmas are important for understanding laser absorption and energy transport. We will describe two new 10-channel XRD systems that have been installed at the LLNL Novette facility for use in the 0.15- to 1.5-keV range. Since XRD … more

Date: September 15, 1983

Creator: Tirsell, K.G.; Lee, P.H.Y.; Nilson, D.G. & Medecki, H.

Item Type: Article

Partner: UNT Libraries Government Documents Department

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1982 laser program annual report

This annual report covers the following eight sections: (1) laser program review, (2) laser systems and operation, (3) target design, (4) target fabrication, (5) fusion experiments program, (6) Zeus laser project, (7) laser research and development, and (8) energy applications. (MOW)

Date: August 1, 1983

Creator: Hendricks, C.D. & Grow, G.R. (eds.)

Item Type: Report

Partner: UNT Libraries Government Documents Department

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High Energy Laser Facilities at Lawrence Livermore National Laboratory

High energy laser facilities at Lawrence Livermore National Laboratory are described, with special emphasis on their use for equation of state investigations using laser-generated shockwaves. Shock wave diagnostics now in use are described. Future Laboratory facilities are also discussed.

Date: June 1, 1981

Creator: Holmes, N. C.

Item Type: Article

Partner: UNT Libraries Government Documents Department