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H.G. Ahlstrom
1977 Volume 4 Issue 4 Pages
1-16
Published: March 20, 1977
Released on J-STAGE: November 22, 2010
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The Lawrence Livermore Laboratory solid state laser system, ARGUS, has successfully performed laser implosion experiments at power levels exceeding 2 TW. D-T filled glass microspheres have been imploded to yield thermonuclear reaction products in excess of 10
8 per event. Neutron and a time of flight measurements indicete that D-T ion temperatures of (3-4.5 keV) and a density confinement time product (nτ) of (1-3) ×10
12 were obtained in these experiments. Typically two 30J, 30 psec pulses of 1.06μm light were focused on targets using 20 cm aperture f/1 lenses, producing intensities at the target in excess of10
16 W/cm
2. An extensive array of diagnostics routinely monitored the laser performance and the laser target interaction process. Measurements of absorption and asymmetry in both the scattered light distribution and the ion blow off is evidence for non-classical resonant processes absorption mechanisms and density scale heights of the order of 2 μm or less. The symmetry of the thermonuclear burn region is investigated by monitoring the α particle flux in several directions, and an experiment to image the thermonuclear burn region is in process. These experiments significantly extend our data base and our understanding o.
- laser induced thermonuclear implosions and the basic laser plasma interaction physics from the 0.4 to 0.7 TW level of previous experiments.
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E.K. Storm, H.G. Ahlstrom, J.A. Monies, J.E. Swain, V.C. Rupert, D.W. ...
1977 Volume 4 Issue 4 Pages
17-31
Published: March 20, 1977
Released on J-STAGE: November 22, 2010
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A focusing system which utilizes two f/0.47 doublets in conjunction with ellipsoidal mirrors produces two focusing cones with half angles of 81.5°. This system has been used with the LLL Janus laser system to irradiate and implode DT filled glass microshells-80 μm diameter. The purpose of the system was to provide more uniform heating of the pusher and compression of the fuel than had been obtained with Janus irradiated targets using f/l lenses. Neutron yields of-l0
7 per event have been obtained and x-ray micrographs indicate that the heating of the pusher was more uniform. Also the implosions are definitely more spherical than those obtained with the f/l lenses. Data is also presented which add further confirmation to the importance of absorption by plasma wave resonance for non normal incidence of the laser light with the target.
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C. Yamanaka, M. Yokoyama, S. Nakai, T. Yamanaka, Y. Izawa, Y. Kato, T. ...
1977 Volume 4 Issue 4 Pages
32-50
Published: March 20, 1977
Released on J-STAGE: November 22, 2010
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Takashi Yabe, Keishiro Niu
1977 Volume 4 Issue 4 Pages
51-59
Published: March 20, 1977
Released on J-STAGE: November 22, 2010
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The new flux-limited theory including the ion-wave effects is presented. Preliminary results of the two-dimensional particle simulations support this theory.
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R.K. Osborn, F.J. Mayer
1977 Volume 4 Issue 4 Pages
60-70
Published: March 20, 1977
Released on J-STAGE: November 22, 2010
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The elementary, self-similar solutions of single fluid hydrodynamics have been frequently employed
(1, 2) to study diverse aspects of fusion implosions. We have used them for the explicit purpose of attempting empirical correlations among various parameters measured in the laser-fusion experiments conducted by KMSF.
Some of the measurable parameters correlated by these model calculations are: D-T neutron yields; spectra and total energy radiated as X-rays; compression; initial target radii; thermal energy at peak compression; etc. In spite of the over-simplified nature of the physical model, the correlations are surprisingly good.
A two fluid version of the same model-the electron and ion fluids coupled by electrostatic forces-was also investigated perturbation-wise relative to the uncoupled solutions. It was found that substantial, relative to thermal, energy could be stored as plasma oscillations.
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T. Yamanaka, S. Nakai, Y. Kato, T. Sasaki, M. Matoba, K. Yoshida, Y. M ...
1977 Volume 4 Issue 4 Pages
71-79
Published: March 20, 1977
Released on J-STAGE: November 22, 2010
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TETSURO IZUMITANI
1977 Volume 4 Issue 4 Pages
80-85
Published: March 20, 1977
Released on J-STAGE: November 22, 2010
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Keith Boyer
1977 Volume 4 Issue 4 Pages
86-106
Published: March 20, 1977
Released on J-STAGE: November 22, 2010
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B. Ahlborn, S. Ariga, S. Ishii
1977 Volume 4 Issue 4 Pages
107
Published: March 20, 1977
Released on J-STAGE: November 22, 2010
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A two stage iodine laser is being constructed and will be usedfor laser-plasma research. An output of 5J/5nS is tentatively expected. An optical isolator, which utilizes an electrical discharge in an iodine gas, has been developed and will be usedto suppress parasitic oscillations in amplifiers.
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Keith Boyer
1977 Volume 4 Issue 4 Pages
108-117
Published: March 20, 1977
Released on J-STAGE: November 22, 2010
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Ray E. Kidder
1977 Volume 4 Issue 4 Pages
118-133
Published: March 20, 1977
Released on J-STAGE: November 22, 2010
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Required values of thermonuclear encrgy-gain, inertial confinement, laser-pulse energy and power for both electric power production by laser-fusion and for plutonium breeding by laser fusion-fission are obtained from simple considerations, and are tabulated for purposes of comparison.
It is found that bveeder requirements are very significantly less demanding, suggesting that plutonium breeding is a much more feasible near-term term goal of laser fusion.
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P.M. Campbell, P. Hammerling, R.R. Johnson, J.J. Kubis, F.J. Mayer, D. ...
1977 Volume 4 Issue 4 Pages
134-152
Published: March 20, 1977
Released on J-STAGE: November 22, 2010
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Laser-driven implosion experiments using DT-gas-filled spherical glass-shell targets are described. Neutron yields to 5 x 10
7 are produced from implosions of small ( - 55-11m-diameter) tarots spherically illuminated with an on-target laser power of 0.4 terawatt. Nuclear reaction product diagnostics, X-ray pinhole photographs, fast-ion spectra and X-ray measure-ments are used in conjunction with hydrodynamic computer code simulations to investigate the implosion phenomenology as well as the target coronaevolution. Simulations using completely classical effects are not able to descri by the full rang f experimental data. Electron or radiation preheating may be required to explain some implosion measurements.
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J.A. Stamper, S.E. Bodner, P.G. Burkhalter, R. Decoste, G.A. Doschek, ...
1977 Volume 4 Issue 4 Pages
153-171
Published: March 20, 1977
Released on J-STAGE: November 22, 2010
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A discussion is given of selected topics relating to experimental studies of laser-matter interactions under conditions of interest to laser-fusion. The NRL laser system, PHAROS II, designed for such studies, is first described. Some of themore novel diagnostics (probing beam, ion, x-ray) are then described. Finally, adiscussion is given of two experimental studies which yield information (B-fielddependence and inhibition) about thermal transport.
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Katsunobu Nishihara, Kazuhiro Nozaki, Toshiya Taniuti, Naruyoshi Asano
1977 Volume 4 Issue 4 Pages
172-190
Published: March 20, 1977
Released on J-STAGE: November 22, 2010
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Yi Jung Yu, Richard. K Osborn
1977 Volume 4 Issue 4 Pages
191-192
Published: March 20, 1977
Released on J-STAGE: November 22, 2010
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A theory for the nonlinear (with respect to the electric field) Faraday effect has been developed and applied to a simple model. Within the frame-work of this model our analysis shows that the ratio of the nonlinear Verdetconstant to the linear Verdet constant is proportional to the intensity of theincident light and depends on the frequency of light, the excitation energyof the model molecule, and the temperature of the medium. This ratio is smallunder ordinary conditions. However, under certain circumstances it may becomelarge. enough for experimentalobservation.
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K.N. Sato, S. Okada, S. Kogoshi, S. Sudo, H. Tsuji, Y. Ohwadano, T. Se ...
1977 Volume 4 Issue 4 Pages
193-210
Published: March 20, 1977
Released on J-STAGE: November 22, 2010
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A new system for directly producing high-temperature high-quality deuterium plasmas within any type ofmagnetic containers has been constructed and operated, in which an on-line computer control technique is utilized to capture a falling deuterium ice-pellet bypulsed laser beam (s). Some experimental results on the fundammental physical properties of plasmas produced andinteractions with nearly uniform magnetic field arepresented. As an immediate application of this particular new plasma production method, detailed studies ofspindle-cusp confinement properties for laser-producedhigh-beta deuterium plasma are being continued. Someof thecomputer analyses for these problems are alsoreviewed.
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M.J. LUBIN
1977 Volume 4 Issue 4 Pages
211-227
Published: March 20, 1977
Released on J-STAGE: November 22, 2010
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J.A. Stamper, S.E. Bodner, P.C. Burkhalter, R. Decoste, C.A. Doschck, ...
1977 Volume 4 Issue 4 Pages
228
Published: March 20, 1977
Released on J-STAGE: November 22, 2010
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A discussion is given of selected topics relating to experimental studies of laser-matter interactions under conditionsof interest to laser-fusion. The NRL laser system, PHAROS II, designed for such studies, is first described. Some of the morenovel diagnostics (probing beam, ion, x-ray) are then described. Finally, a discussion is given of two experimental studies which yield information (B-field dependence and inhibition) about thermaltransport.
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E.B. Goldman, L.M. Goldman, J. Delettrez, J. Hoose, S. Jackel, G.W. Le ...
1977 Volume 4 Issue 4 Pages
229-244
Published: March 20, 1977
Released on J-STAGE: November 22, 2010
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We report here on the theoretical interpretation of results related to compression experiments performed on the University of Rochester's four beam laser system. The experimental results show volume reduction on the order of 300 with compressed electron temperatures on the order of 1 KeV, critical surface temperatures also about 1 KeV and a density plateau in the vicinity of the critical surface. The theoretical work focusses on the effect of absorption time history, of reduced flux limits and of variation of the suprathermal electron distribution on the replication of these experiments.
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T. Mochizuki, C. Yamanaka
1977 Volume 4 Issue 4 Pages
245-254
Published: March 20, 1977
Released on J-STAGE: November 22, 2010
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This paper was presented in US-Japan Seminar in Laser Interaction with Matter held at University of Rochester-November 2-5, 1976 Introduction
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Tatsuo YAJIMA
1977 Volume 4 Issue 4 Pages
255-261
Published: March 20, 1977
Released on J-STAGE: November 22, 2010
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The frequency characteristic of an optical mixing process of the type ω
3=2ω
1-ω
2 provides a general and useful means of determining both the energy and phase relaxation times in the range of 10
-12
∼10
-15 sec associated with excited states of dense media.This paper describes the outline of basic theory and the experimental demonstration on molecular transitions. Applications to plasma media will also be discussed.
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N.C. Luhmann
1977 Volume 4 Issue 4 Pages
262
Published: March 20, 1977
Released on J-STAGE: November 22, 2010
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ALEXANDER J GLASS, JOHN B TRENHOLME
1977 Volume 4 Issue 4 Pages
263-269
Published: March 20, 1977
Released on J-STAGE: November 22, 2010
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J.R. FREEMAN, STEVEN A. GOLDSTEIN, G.R. HADLEY, D.L. JOHNSON, T.H. MAR ...
1977 Volume 4 Issue 4 Pages
270-277
Published: March 20, 1977
Released on J-STAGE: November 22, 2010
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A review of Sandia Laboratories' program to investigate the feasibility of achieving inertial confinement fusion using pulsed power technology to produce focused electron and ion beams is presented. Recent results are discussed, including beam focusing, target interaction studies, and accelerator development.
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J.R. Freeman, M.J. Clauser, M.J. Clauser
1977 Volume 4 Issue 4 Pages
278-301
Published: March 20, 1977
Released on J-STAGE: November 22, 2010
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This paper reports calculations of the growth of Rayleigh-Taylor instabilities (1) in the ablator-pusher region such as may be caused byirregularities in an electron beam, and (2) in the pusher fuel interface, aproblem common to all inertial confinement fusion targets. For the firstcase, it is found that shallow density gradients and scattering of the beamby the target, both stabilize the shorter wavelength instabilities, whichwould otherwise grow the most rapidly. In the second case, it is found thatmoderately short wavelength instabilities may not degrade the targetperformance as much as has previously been supposed.
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Helmut Schwarz, Romualdo Tabensky
1977 Volume 4 Issue 4 Pages
302-320
Published: March 20, 1977
Released on J-STAGE: November 22, 2010
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An exact solution of the general equation of notion of charged particles in a medium of refractive index n subjected to irradiation of electromagnetic waves at any intensity and frequency is. given. No approximations are necessary even for the relativistic case. Linearly polarized as well as circularly poarized waves are considered. Self-induced fields due to the generated charged particle currents have very little influence on the solutions, especially at higher intensities, where electron-positron pair production can be expected.
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Koichi TOYODA, Susumu NAMBA
1977 Volume 4 Issue 4 Pages
321-323
Published: March 20, 1977
Released on J-STAGE: November 22, 2010
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C Yamanaka
1977 Volume 4 Issue 4 Pages
324-325
Published: March 20, 1977
Released on J-STAGE: November 22, 2010
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[in Japanese]
1977 Volume 4 Issue 4 Pages
326-335
Published: March 20, 1977
Released on J-STAGE: November 22, 2010
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Chiyoe YAMANAKA
1977 Volume 4 Issue 4 Pages
a1
Published: March 20, 1977
Released on J-STAGE: November 22, 2010
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