DOCSLIB.ORG

2Fi Lawrence Livermore Laboratory I*^P^*S

Total Page：16

File Type：pdf, Size：1020Kb

Download full-text PDF Read full-text
2Fi Lawrence Livermore Laboratory I*^P^*S V PREPRINT UCRL- 77944 Ur,\>\--m'>te^-2fi Lawrence Livermore Laboratory STATUS OF LARGE NEODYHIUM GLASS LASERS James A. Glaze, William W. Simmons and Wilhelm F. Hagen March ID, 1976 mm This Paper was Prepared for Submission to the Society of Photo-Optical Instrumentation Engineers SPIE Meeting, Reston, VA March 22-23, 1976 This is a preprint ot a paper intended for publication in a journal or proceedings. Since changes may be made before publication, this preprint is made available with the understanding that it will not be cited or reproduced without the permission of the author. i*^P^*S' ««*- -»v«>*^_ DiSTRiKUTiONC; 7602 STATUS OF LARGE NEODYMIUM GLASS LASERS* •ponum] by llw Van* Stu „ o| M[l Blmc*i ng PttritrmtM A« Canes A. Glaje, William H. Simmons and Wlhelm F. Hagen uitKnnmtion. 01 IIKU tiqitiqRt, Laser Fusion Division, Lawrence Livermore Laboratory nmnir. <ieir» 01 tngfttd Llvermore, California 94550 *IR£t» ottTIfcnitttllly f.tth mrnw en>,«l* owned (HJHi. Introduction The Nd:Glass laser is used extensively throughout the world for laser fusion and laser plasma Inter­ action studies. Its popularity, to a large extent, stems from the fact that 1t 1s capable of operating reliably in the subnanosecond-terawatt power regime. In addition, the technology necessary to combine a large number of laser chains to produce a system capable of multi-terawatt performance currently exists and is being applied. At the Lawrence Livermore Laboratory two large laser systems are currently in operation and two are under construction. The OANUS and CYCLOPS systems produce 0.5 and 1 terawatt of focusable power 1n 0.1 ns respectively. These systems are being used for target irradiation and beam propagation experiments and provide our basic test beds for laser component and system development. The ARGUS laser is a two am, 3 terawatt system dedicated to fusion target irradiation experiments. This system Is scheduled for initial operation In March, 1976. The SHIVA system which is scheduled for early testing in mid-1977, is a 20-am system designed to operate at 20-30 terawatts. This system is designed to demonstrate significant thermo­ nuclear burn from the isentroplc compression of 0-T targets. In addition to these syst«s, various system upgrades are currently being evaluated. Figure 1 Is a graphical presentation of the LLL NdtGlass laser development program; the ordinate gives the anticipated TN fuel pellet gain that can be achieved with each system. The shaded areas refer to the performance of system upgrades which, to date, have not been runded. In this paper the elements of a Nd:Glass laser chain as it is constructed for fusion experiments are des­ cribed. Also presented is a brief overview of the ARC-US and SHIVA systems. For a >»f«"1pn of the JANUS and CYCLOPS lasers, the reader is referred to the 1974 LLL Laser Program Annual Report (UCRL-50021-74) and to the review article of Reference 11, % LASER FUSION ENERGY YIELD PROJECTIONS 3 c 10 - Pure fusion reactor feasibility | 101 - Net fusion energy gain ' 01 w 10° -Scientific breakeven Oj •" in S. io-' 10* SHIVA Upgrade Isentropic compression 3 (100-300 TW) 10 fSHIVA(25-30 TW) 4 io- Neutron Argus IV (5-10 TW) _ spectrum 10'5 Argus II (2-4 TW) A| na oData 6 P f<tJJ Cyclops (1-1.5 TW) 10 spectrum 7 lectrumtf T^ 10 Janus II (0.4 TW) 8 10 Janus I (0.2 TW) NT9 LT 4- 74 75 76 77 78 79 80 81 82 Calendar year fig. Schematic presentation of the Nd:Glass laser development program at Llvermore. The ordinate gives the anticipated TN fuel pellet gain that can be achieved with each system. The shaded regions refer to the performance of system upgrades which have not been funded to date. The ARGUS II and SHIVA systems are discussed in this paper. r\ I •This work was performed under the auspices of the U.S. Energy Research and Development Administration. AIA { Contract Number K-?405-Eng-48. , __ \j \ >, laser Chain Description In discussing the makeup of a Nd:Glass laser system for use in target Irradiation experiments, it is useful tn consider a block diagram of <> single laser chain. Figure Z shows such a diagram for a chain comprised of both rod and disk amplifiers. Below we discuss the various components shown 1n this dlaqram. BLOCK DIAGRAM FOR A Nd:GLASS LASER CHAIN Master Pulse Pulse Pre­ Pre— pulse oscillator switch-out shaper amplifiers isolation Apodizing Rod ASE Disk ASE amplifier amplifier aperture groups isolation groups isolation I Spatial filter, polarizer-rotator Disk amplifier Spatial filter . V — Typical disk amplifier group Fig. 2. Block diagram of a typical Nd:Glass laser chain as 1t would be staged for laser fusion expenrrents. A disk amplifier group is also shown. Such a group may contain several amplifier heads; these heads would generally have the same clear aperture. The rod amplifier groups are staged in a similar manner. The master oscillator used at LLL is a NdrYAG laser passively mode locked with a flowing bleaehahle dye- Bandwidth is established with an ctalon whose temperature is maintained within + Q.1°C with a closed cycle coolant loop. Uniform pumping of the rod 1s achieved with an afocal double ellipse reflector qeoretry The oscillator output consists of a train of subnanosecond pulses, one of which 1s selected and switched out for injection into the preamplifier stages. Energy of the largest pulse in the train 1s typically 2 mJ. Because of the statistica1 manner in which the dye is bleached by fluorescent noise spikes, this oscillator does not have the pulse-U-pulse temporal stability that is desired for large system applications. (Vari­ ations of up to 30% are sometimes observed). Attempts are currently being rude to develop oscillators with improved longitudinal mode discrimination. One promising approach.uses a synchronously driven Intracavity loss modulator (fast Pockels' cell) in addition tc the dye cell.('J Transform limited pulses ranging from <50 psec to >.5 nsec have been achieved. This oscillator to date, however, has problems of pulse train Instability thought to arise from Improper impedance matching of the PFN and Pockels1 cell. The oscillator pulse swltchout incorporates a fast Pockels1 ce'll (1 cm diameter) positioned between crossed polarizers. In early designs half-wave voltage was applied to the cell by switching a high-pressure Ng-fllled spark gap with optical energy derived from the early portion of the pulse train. Since the opti­ cal energy arrives at the spark gap in the form of pulses whose spacing (typically 10 ns; is long compared to gap break-down times, it is possible to adjust the gas pressure so that the state of ionization required for full avalanche breakdown across the gap is achieved just prior to the arrival at the Pockels' cell of the pulse selected for switchout. This scheme is widely used, but suffers from jitter in the gap break­ down time, resulting in part fi'om shot-to-shot variability of the pulse train amplitude and In part from electrode degradation.with time. More recently, modern electronic switches have eliminated the troublesome spark gap entirely.**' In the electronic switchout circuit in present use at LIL, a Krytron switch, acti­ vated by an avalanche transistor stack, discharges a stripllne circuit which 1s accurately impedance matched to the Pockels' cell. This circuit derives Us timing signal from the pulse train through a vacuum photo- diode and voltage-settable tunnel diode comparator. By careful adjustment of time delay and threshold voltage, switched-out pulse energy variation can be minimized. The pulse shaper is a device that transforms the temporally gaussian oscillator pulse to i pulse more suitable for target irradiation. Theoretical calculations show that the desired waveform is a function of target size, composition, and available laser energy.(3) Of all the components that comprise the c*iain, this one, to date, Is least clearly defined In terms of performance requirements and construction. However, a large number of schemes have been proposed; these can be broadly characterized as pulse stackers, shutters and active shapers. The stacker produces a composite pulse derived from a single short pulse that is suit? ably delayed and attenuated. A patented scheme using a double etalon is.presently in use at XMS Fusion.W 5 Another scheme uses a Faraday rotator placed between cross polarizers.I '' Successive reflections from thoe *Registered Trademark name. 2 6* v f \i -t* rotator surfaces experience different rotatfons aod nonce different transmissions through the output pola­ rizer. This device, while simple to implement, does not provide an exponentially Increasing signal 15 dOuS the KMS stacker. Optical shutters have been in use for some tine. In this scheme a Pockels' or Kerr cell modulator fs used to chop-out a portion of a longer Q-switchcd pulse. Banduidth limitations on the nodu- 'lator presently Unit pulse rise tic* to about iCO nsec. furthermore, all shutters ire United by an .intrinsic dynamic amplitude range of 3U-40 dp. Active shapers rely on the transmission properties of saturable absorbers. One example is that proposed by Elliott and Kissey.W In their scheme a series of dye"cells are optically gated with combinations of exponential and Russian pulses suitably delayed In tine. Their calculations predict that the puts? shape discussed in Reference 3 can be closely matched. » lasor radiance is limited by both linear and nonlinear wavefront distortions. Static aberrations arising from surface figure error can be as high as 0.4 naves RMS for a laser Such as CYC10PS which has over ISO optical surfaces. Quasistatic aberrations arising fron flash)*:-?-Induced theroal distortion of laser disks can be several waves unless elaborate cooling procedures are adopted.
Load more

Recommended publications
  • Nova Laser Technology
    Nova Laser Technology In building the Nova laser, we have significantly advanced many technologies, including the generation and propagation of laser beams. We have also developed innovations in the fields of alignment, diagnostics, computer control, and image processIng.• For further information contact Nova is the world's most powerful at least 10 to 30 times more energetic John F. Holzrichter (415) 423-7454. laser system. It is designed to heat and than Shiva would be needed to compress small targets, typically 0.1 cm investigate ignition conditions and in size, to conditions otherwise produced possibly to reach gains near unity. only in nuclear weapons or in the Because of the importance of such a interior of stars. Its beams can facility to the progress of inertial fusion concentrate 80 to 120 kJ of energy (in research and because of the construction 3 ns) or 80 to 120 TW of power (in time entailed (at least five to seven 100 ps) on such targets. To couple energy years), the Nova project was proposed to more favorably with the target, Nova's the Energy Research and Development laser light will be harmonically converted Administration and to Congress. It was with greater than 50% efficiency from its decided to base this system on the near-infrared fundamental wavelength proven master-oscillator, linear-amplifier­ (1.05-,um wavelength) to green (0.525- chain laser system used on the Argus ,um) or blue (0.35-,um) wavelengths. The and Shiva systems. We had great goals of our experiments with Nova are confidence in extending this to make accurate measurements of high­ neodymium-glass laser technology to the temperature and high-pressure states of 200- to 300-kJ level.
    [Show full text]
  • Nuclear Diagnostics for Inertial Confinement Fusion (ICF) Plasmas
    PSFC/JA-20-4 Nuclear diagnostics for Inertial Confinement Fusion (ICF) plasmas J. A. Frenje January 2020 Plasma Science and Fusion Center Massachusetts Institute of Technology Cambridge MA 02139 USA The work described herein was supported in part by US DOE (Grant No. DE-FG03-03SF22691), LLE (subcontract Grant No. 412160-001G) and the Center for Advanced Nuclear Diagnostics (Grant No. DE-NA0003868). Reproduction, translation, publication, use and disposal, in whole or in part, by or for the United States government is permitted. Submitted to Plasma Physics and Controlled Fusion Nuclear Diagnostics for Inertial Confinement Fusion (ICF) Plasmas J.A. Frenje1 1Massachusetts Institute of Technology, Cambridge, MA 02139, USA Email: [email protected] The field of nuclear diagnostics for Inertial Confinement Fusion (ICF) is broadly reviewed from its beginning in the seventies to present day. During this time, the sophistication of the ICF facilities and the suite of nuclear diagnostics have substantially evolved, generally a consequence of the efforts and experience gained on previous facilities. As the fusion yields have increased several orders of magnitude during these years, the quality of the nuclear-fusion-product measurements has improved significantly, facilitating an increased level of understanding about the physics governing the nuclear phase of an ICF implosion. The field of ICF has now entered an era where the fusion yields are high enough for nuclear measurements to provide spatial, temporal and spectral information, which have proven indispensable to understanding the performance of an ICF implosion. At the same time, the requirements on the nuclear diagnostics have also become more stringent.
    [Show full text]
  • Lll Laser Program Overview
    I ~ Ellerll APR 13 1~76 ~ illid ~~WJF Destroy Telllllllllill Route - Hold mos. Prepared for U.S . Energy Research & Development lell Administration under Contract No. W-7405-Eng-48 LA.WRENCE LIVERMORE LA.BORATORY LLL LASER PROGRAM LASERS AND LASER APPLICATIONS LLL LASER PROGRAM OVERVIEW ------------------------ During the past year, substantial progress has been thermonuclear burn of microscopic targets containing made toward laser fusion, laser isotope separation, and deuterium and tritium. Experiments are being run on the development of advanced laser media, the three a single-pulse basis , the emphasis being on fa st main thrusts of the LLL laser program. diagnostics of neutron, x-ray, a-particle, and scattered Our accomplishments in laser fusion have included: laser-light fluxes from the target. Our laser source fo r • Firing and diagnosing more than 650 individual this work is the neodymium-doped-glass (Nd:glass) experiments on the O.4-TW Janus laser system laser operating in a master-oscillator, power-amplifier (including many experiments with neutron yields in configuration, where a well-characterized, mode-locked the 107 range). pulse is shaped and ampli fied by successive stages to • Producing 1 TW of on-target irradiation with a peak power of I TW in a 20-cm-diam beam. Cyclops, presently the world's most powerful Thermonuclear burn has been demonstrated. With single-beam laser. successively larger Nd :glass laser systems, we now • Completing the design for the 25-TW Shiva laser expect sequentially to demonstrate significant burn, system and ordering the long-lead-time components. light energy breakeven (equal input and output (The building to house this laser system is on schedule energies) and, finally, net energy gain.
    [Show full text]
  • Laser Confinement Fusion • Use Powerful Laser to Compress And
    Laser Confinement Fusion • Use powerful laser to compress and heat hydrogen • Hydrogen stored in very small pellets • Outside of pellet boiled off by laser beam • Ablation causes plasma • Pellet compressed 4-5 times density of liquid hydrogen •Reaches temperature/pressure of sun core • Get Fusion reaction H 3 + H 2 → He4 + n +14MeV Laser Fusion Reactor • Pellets dropped into reactor • Laser pulse (40 nsec & terawatt) ignites compression wave • Energy from fusion carried in neutrons & helium 3 • Liquid Lithium shield adsorbs neutrons and energy • Regular "steam" generator to get power Argus Laser Fusion Facility • Lawrence Livermore Labs: 2 Terawatt in 1 nsec pulse • Nd:yag/glass laser built in 1976 • Demonstrated concepts for laser confinement fusion • Problem: need to have pellet heated very uniformly • Thus next stage increased number of beams Shiva Laser Fusion Facility • 20 Beam Nd:Yag system • Lawrence Livermore Labs: 30 Terawatt, 1 nsec • Most important result: needed to go to shorter wavelength National Ignition Facility • National Ignition Facility (NIF) newest design • 1.8 megaJoul, frequency tripled Nd:glass laser • 10 ps pulse, 1019 W/cm2 • 192 beam lines combined • Test concepts with Peta Wat laser • 1.25x1015W, 0.55 ps pulse, 1021 W/cm2 • Located at Lawrence Livermore Labs Laser Flight • Use orbital laser satellites to send down beams orbital solar power satellites • Light focused and tracts aircraft • Flight takes off normally - regular engines • Switches to laser drive for cruse section of flight • Significant savings in
    [Show full text]
  • Fusion Reactions
    Nuclear Fusion Technology Dr. BC Choudhary, Professor Applied Science Department, NITTTR, Sector-26, Chandigarh-160019. Content Outlines Review of Nuclear Processes Nuclear Fusion Reactions Fusion Reactor Technologies Technological Developments Pros and Cons Foreseeable trends Four Forces of Nature Systematic Information about Nucleus . Nuclear density at the centre of the nucleus 44 3 0 10 nucleons/m Density of nucleons (r) in the inner region of the nucleus is about same for all nuclei. Surface thickness of all nuclei are very similar 1/3 Radius of nucleus, R = R0 A , small variation in radii . NOT ALL NUCLEI ARE SPHERICAL. Energies of nucleons in nucleus 10 MeV . ALL NUCLEI ARE NOT STABLE Nuclear Stability Proton unstable Stable nuclei Neutron unstable Stable n:p = 1.2 –1.4 Measure of Nuclear Stability . Binding Energy per nucleon 2 EB(Z,N) = {ZMp+NMn - M(Z,N)} c • Nuclei with the largest binding energy per nucleon are the most stable. • The largest binding energy per nucleon is 8.7 MeV, for mass number A = 60. • Beyond Bismuth, A = 209, nuclei are unstable. Nuclear Processes . We can release energy by creating nuclei that are more strongly bound (increasing Eb) Fission: Heaviest nuclei 56 Eb Fe split into smaller fragments. 238 N U Fusion: Lightest nuclei 1H combine to form heavier N nuclei. Both the processes evolve large amount of energy. Nuclear Fission and Fusion Nuclear fission: A large nucleus splits into several small nuclei when impacted by a neutron, and energy is released in this process Nuclear fusion: Several small nuclei fuse together and release energy Electricity from Nuclear Fission Nuclear power plants account ~17 percent of the worlds power.
    [Show full text]
  • Fusion Devices
    PP.EPRINI UCRL-S0060 r~ _ _ZZ~ j Lawrence Uvermore Laboratory FUSION DEVICES T. K. FOWLER OCTOBER 11, 197"/ Presented at the EPRI Executive Seminar on Fusion, October 11-13, 1977 San Francisco, California This is a preprint of a paper intended for publication in a Journal or proceedings. Since changes may be made before publication, this preprint is made available with the understanding that It will not be cited or reproduced without the permission of the author. )0B ©1STR1BUT10N OF THIS DOCUMENT IS UNLIMITED 1. FUSION DEVICES T. K. Fowler In this talk, I will emphasize the expected developments in fusion research over the next five years. This will be the formative period for fusion in the foreseeable future. It will also be a formative period in national energy policy that will impact many years to come. As the previous speakers have said, we believe that fusion is a matter of great interest to the electric utilities. We need your support and your guidance in this critically formative period. I will give a brief description of the three mainline activities of the research program in fusion. These include two magnetic systems, one called the Tokamak and one called the mirror machine, and also laser fusion. While I am going to concentrate on these three mainline activities, they are not the only possibilities. Fusion is a rich subject with many possible outcomes, all of which may be interesting to the utilities. However, the first ways that fusion will be made practical will, I think, come from the approaches I will describe, simply because each of these concepts already has behind it a long history of scientific development that should culminate in the next five years.
    [Show full text]
  • Nuclear Diagnostics for Inertial Confinement Fusion (ICF) Plasmas
    Plasma Physics and Controlled Fusion TOPICAL REVIEW Nuclear diagnostics for Inertial Confinement Fusion (ICF) plasmas To cite this article: J A Frenje 2020 Plasma Phys. Control. Fusion 62 023001 View the article online for updates and enhancements. This content was downloaded from IP address 18.21.213.6 on 07/01/2020 at 20:53 Plasma Physics and Controlled Fusion Plasma Phys. Control. Fusion 62 (2020) 023001 (44pp) https://doi.org/10.1088/1361-6587/ab5137 Topical Review Nuclear diagnostics for Inertial Confinement Fusion (ICF) plasmas J A Frenje Massachusetts Institute of Technology, Cambridge, MA 02139, United States of America E-mail: [email protected] Received 12 December 2017, revised 13 September 2019 Accepted for publication 25 October 2019 Published 7 January 2020 Abstract The field of nuclear diagnostics for Inertial Confinement Fusion (ICF) is broadly reviewed from its beginning in the seventies to present day. During this time, the sophistication of the ICF facilities and the suite of nuclear diagnostics have substantially evolved, generally a consequence of the efforts and experience gained on previous facilities. As the fusion yields have increased several orders of magnitude during these years, the quality of the nuclear-fusion-product measurements has improved significantly, facilitating an increased level of understanding about the physics governing the nuclear phase of an ICF implosion. The field of ICF has now entered an era where the fusion yields are high enough for nuclear measurements to provide spatial, temporal and spectral information, which have proven indispensable to understanding the performance of an ICF implosion. At the same time, the requirements on the nuclear diagnostics have also become more stringent.
    [Show full text]
  • December 1994
    ■ December 1994 && ReviewReview The National Ignition Facility University of California Lawrence Livermore National Laboratory ■ December 1994 About the Cover This month’s E&TR is dedicated to discussions of various aspects of the National Ignition Facility (NIF). The cover features images of the heart of the & Review latest and largest inertial fusion laser being designed by LLNL researchers for use in the international laser science community. In the background on the front cover is an engineering drawing of the 192-beam target chamber where ignition of NIF targets takes place. The inset is an artist’s rendering of the NIF in operation. It shows an indirect-drive target contained within a metal cylinder called a hohlraum. The blue laser beams are depositing their energy on the inside of the hohlraum. There the energy is converted to x rays that heat the target intensely, causing it to implode and ignite for a fraction of a second with the energy intensity of the The National interior of a star. On the back cover is a photograph Ignition Facility of an indirect target that contains a tiny amount of University of California hydrogen-isotope fuel. The hohlraum is about Lawrence Livermore National Laboratory 6 millimeters in diameter; the target inside is about 3 millimeters in diameter. The design, manufacture, and testing of these targets by Laboratory scientists is integral to the success of experiments performed on the NIF. About the Journal The Lawrence Livermore National Laboratory, operated by the University of California for the United States Department of Energy, was established in 1952 to do research on nuclear weapons and magnetic fusion energy.
    [Show full text]
  • Diagnosing Inertial Confinement Fusion Implosions at OMEGA and the NIF Using Novel Neutron Spectrometry
    PSFC/RR-12-1 Diagnosing Inertial Confinement Fusion Implosions at OMEGA and the NIF Using Novel Neutron Spectrometry D. T. Casey January, 2012 Plasma Science and Fusion Center Massachusetts Institute of Technology Cambridge MA 02139 USA This work was supported in part by the U.S. Department of Energy (DE-NA0000877 and DE-FG52-09NA29553), the Fusion Science Center at the University of Rochester (PO #415023-G, UR Account #5-24431), the Laboratory for Laser Energetics at the University of Rochester (414090-G), and the Lawrence Livermore National Laboratory (B580243). Reproduction, translation, publication, use and disposal, in whole or in part, by or for the United States government is permitted. Diagnosing Inertial Confinement Fusion Implosions at OMEGA and the NIF Using Novel Neutron Spectrometry by Daniel Thomas Casey B.S. Nuclear Engineering (2005) University of New Mexico SUBMITTED TO THE DEPARTMENT OF NUCLEAR SCIENCE AND ENGINEERING IN PARTIAL FULFILLMENT OF THE REQUIREMENTS FOR THE DEGREE OF DOCTOR OF PHILOSOPY IN NUCLEAR SCIENCE AND ENGINEERING AT THE MASSACHUSETTS INSTITUTE OF TECHNOLOGY February 2012 ©2012 Massachusetts Institute of Technology. All rights reserved. Signature of Author:_____________________________________________ Department of Nuclear Science and Engineering February 15th, 2012 Certified by:___________________________________________________ Richard Petrasso Senior Research Scientist Thesis Supervisor Accepted by:__________________________________________________ Ronald Parker Professor of Nuclear Science and Electrical
    [Show full text]
  • The Novette Laser Facility: a Step in the Evolution of High-Power Laser Systems
    Energy and Technology Review ~awrence Livermore National Laboratory January 1985 The Novette Laser Facility: A Step in the Evolution of High-Power Laser Systems Work with the recently dismantled Novette laser, LLNL's flexible, high-energy-density experimental facility, has profoundly affected our understanding of laser-plasma coupling phenomena. Novette was the first in the Laboratory's series of successively more powerful and complex laser systems to incorporate full-power harmonic conversion of laser light in nonlinear birefringent media, and with it we probed the details of the design for the Nova laser. For further information contact In the course of inertial-confinement system in the evolving series of Kenneth R. Manes (415) 422-0681. fusion (ICF) research at LLNL, we have Laboratory lasers was designed to exploit designed and built a series of the knowledge gained through successively more powerful and complex experiments with its predecessor. laser systems: Janus, Cyclops, Argus, The Novette laser was the first to Shiva, Novette, and soon the next incorporate full-power harmonic generation, Nova. All of these laser upconversion in order to test the systems used or will use chains of hypothesis that short-wavelength laser neodymium-glass amplifiers (in the form pulses couple energy more efficiently to of scaled modules), and they all share target plasmas than longer ones do. the same fundamental design, called Thus, the Novette laser provided MOPA-a Master Oscillator driving a a flexible, high-energy-density single-pass Power Amplifier. Each experimental facility to bridge the gap 10 DEFENSE PROGRAMS between the Shiva and Nova lasers, theoretical and experimental studies have while allowing us to probe the details of indicated that coupling and, therefore, the Nova design.
    [Show full text]
  • 90054 PREPRINT UCEL—9C054 Def,4 005213 This Paper Was
    UCRL- 90054 PREPRINT CLKF ^3i0c 'iU NOVETTE FACILITY: ACTIVATION AND PRELIMINARY EXPERIMENTAL RESULTS Kenneth R. Manes UCEL—9C054 DEf,4 005213 This paper was prepared for submittal to the 10th Symposium on Fusion Engineering Philadelphia, Pennsylvania December 5-9, 1983 November 30, 1983 This is a preprint of a paper intended for publication in a journal or proceedings. '. changes may be nude before publication, this preprint is made available with the un­ derstanding that it will not be cited or reproduced without the permission of the author. DISCLAIMER This report was prepared as an account of work sponsored by an agency of the United States Government. Neither the United States Government nor any agency thereof, nor any of their employees, makes any warranty, express or implied, or assumes any legal liability or responsi­ bility for the accuracy, completeness, or usefulness of any information, apparatus, product, or process disclosed, or represents that its use would not infringe privately owned rights. Refer­ ence herein to any specific commercial product, process, or service by trade name, trademark, manufacturer, or otherwise does not necessarily constitute or imply its endorsement, recom­ mendation, or favoring by the United States Government or any agency thereof. The views -tfb\ and opinions or authors expressed herein do not necessarily state or reflect those of the OF THIS mrnin is UNIIMITED United States Government or any agency thereof. "£. FACILITY: ACTIVATION AND PRELIMINARY EXPERIMENTAL RESULTS* Kenneth R. Manes Lawrence Llvermore National Laboratory P.O. Box SS08, L-493 Livermore. California 94550 (415) 422-0681 wavelength laser-plasma interaction phenomena relevant to inertial confinement fusion.
    [Show full text]
  • Brillouin Scatter in Laser-Produced Plasmas
    V MASTER PREPRINT UCRL- 79769 Lawrence Livermore Laboratory ERILLOUIN SCATTER IN LASER-PRODUCED PLASMAS D. W. Phillion, W. L. Kruer, and V. C. Rupert- July 18, 1977 This paper was presented as an invited paper at the 7th Annual Anomalous Absorption Conference, Ann Arbor, Michigan, May 1977. This !s a preprint of a paper intended for publication in adjournal or proceedings. Since changes may be made before publication, this preprint is made available with the understanding t!.st it will not be cited or reproduced without the permission of the author. DISTRIBUTION OF THtS DOCUMENT IS UNLIMITED UCRL-79769 * BRILLOUIN SCAITER IN LASER-PRODUCED PLASMAS D. W. Phlllion, W. L. Kruer, and V. C. Rupert Lawrence Livermore Laboratory, University of California Livermore, California Abstract The absorption of intense laser light is found to be reduced when targets are irradiated by 1.06 um light with ong pulse widths (150-ifOO psec) and large focal spots (100-250 urn). Estimates of Brillouin scatter which account for the finite heat apacity of the underdense plasma predict this reduction. Spectra of the back reflected light show red shifts indicative of Brillouin scattering. thD „ w« P tn ia>«m .[ WOlh . the 1 rutrd Suiti Oivnnme <h* I'niic. ,'nnnl Sti » [ net jv Rnt«nn in J tWvtl ptntni AdmjnulMUon. r*n wiy ..1 »n> kjJ rtputiubJiiy foi ihc or uicfulnr indirmitmn. ippjuiiii pftKYll OUv „wd. u (hjl Iti UV tMnnft pn> Jltly owned IIKJIIV * • Work performed under the auspices of the U.S. Energy Research and Development Administration, contract No. W-7^05-Eng-48.
    [Show full text]