1
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Gao CZ, Zhang CB, Yu CX, Xu XF, Wang SC, Yang C, Hong ZY, Fan ZF, Wang P. Stochastic radiative transfer in random media: Pure absorbing cases. Phys Rev E 2020; 102:022111. [PMID: 32942389 DOI: 10.1103/physreve.102.022111] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/16/2020] [Accepted: 07/21/2020] [Indexed: 11/07/2022]
Abstract
We study stochastic radiation transport through random media in one dimension, in particular for pure absorbing cases. The statistical model to calculate the ensemble-averaged transmission for a binary random mixture is derived based on the cumulative probability density function (PDF) of optical depth, which is numerically simulated for both Markovian and non-Markovian mixtures by Monte Carlo calculations. We present systematic results about the influence of mixtures' stochasticity on the radiation transport. It is found that mixing statistics affects the ensemble-averaged intensities mainly due to the distribution of cumulative PDF at small optical depths, which explains well why the ensemble-averaged transmission is observed to be sensitive to chord length distribution and its variances. The effect of the particle size is substantial when the mixtures' correlation length is comparable to the mean free path of photons, which imprints a moderately broad transition region into the cumulative PDF. With the mixing probability increasing, the intensity decreases nearly exponentially, from which the mixing zone length can be approximately estimated. The impact of mixed configuration is also discussed, which is in line with previous results.
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Affiliation(s)
- Cong-Zhang Gao
- Institute of Applied Physics and Computational Mathematics, Beijing 100088, People's Republic of China
| | - Cun-Bo Zhang
- Institute of Applied Physics and Computational Mathematics, Beijing 100088, People's Republic of China
| | - Cheng-Xin Yu
- Institute of Applied Physics and Computational Mathematics, Beijing 100088, People's Republic of China
| | - Xue-Feng Xu
- Institute of Applied Physics and Computational Mathematics, Beijing 100088, People's Republic of China
| | - Shuai-Chuang Wang
- Institute of Applied Physics and Computational Mathematics, Beijing 100088, People's Republic of China
| | - Chen Yang
- Institute of Applied Physics and Computational Mathematics, Beijing 100088, People's Republic of China
| | - Zhen-Ying Hong
- Institute of Applied Physics and Computational Mathematics, Beijing 100088, People's Republic of China
| | - Zheng-Feng Fan
- Institute of Applied Physics and Computational Mathematics, Beijing 100088, People's Republic of China
| | - Pei Wang
- Institute of Applied Physics and Computational Mathematics, Beijing 100088, People's Republic of China
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2
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Campos A, Morgan BE. Direct numerical simulation and Reynolds-averaged Navier-Stokes modeling of the sudden viscous dissipation for multicomponent turbulence. Phys Rev E 2019; 99:063103. [PMID: 31330657 DOI: 10.1103/physreve.99.063103] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/26/2019] [Indexed: 11/07/2022]
Abstract
Simulations of a turbulent multicomponent fluid mixture undergoing isotropic deformations are carried out to investigate the sudden viscous dissipation. This dissipative mechanism was originally demonstrated using simulations of an incompressible single-component fluid [S. Davidovits and N. J. Fisch, Phys. Rev. Lett. 116, 105004 (2016)10.1103/PhysRevLett.116.105004]. By accounting for the convective and diffusive transfer of various species, the current work aims to increase the physical fidelity of previous simulations and their relevance to inertial confinement fusion applications. Direct numerical simulations of the compressed fluid show that the sudden viscous dissipation of turbulent kinetic energy is unchanged from the single-component scenario. More importantly, the simulations demonstrate that the mass fraction variance and covariance for the various species also exhibit a sudden viscous decay. Reynolds-averaged Navier-Stokes simulations were carried out using the k-l model to assess its ability to reproduce the sudden viscous dissipation. Results show that the standard k-l formulation does not capture the sudden decay of turbulent kinetic energy, mass-fraction variance, and mass-fraction covariance for simulations with various compression and expansion rates, or different exponents for the power-law model of viscosity. A new formulation of the k-l model that is based on previous improvements to the k-ε family of models is proposed, which leads to consistently good agreement with the direct numerical simulations for all the isotropic deformations under consideration.
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Affiliation(s)
- Alejandro Campos
- Lawrence Livermore National Laboratory, Livermore, California 94550, USA
| | - Brandon E Morgan
- Lawrence Livermore National Laboratory, Livermore, California 94550, USA
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3
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Curtis A, Calvi C, Tinsley J, Hollinger R, Kaymak V, Pukhov A, Wang S, Rockwood A, Wang Y, Shlyaptsev VN, Rocca JJ. Micro-scale fusion in dense relativistic nanowire array plasmas. Nat Commun 2018. [PMID: 29540753 PMCID: PMC5852030 DOI: 10.1038/s41467-018-03445-z] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022] Open
Abstract
Nuclear fusion is regularly created in spherical plasma compressions driven by multi-kilojoule pulses from the world's largest lasers. Here we demonstrate a dense fusion environment created by irradiating arrays of deuterated nanostructures with joule-level pulses from a compact ultrafast laser. The irradiation of ordered deuterated polyethylene nanowires arrays with femtosecond pulses of relativistic intensity creates ultra-high energy density plasmas in which deuterons (D) are accelerated up to MeV energies, efficiently driving D-D fusion reactions and ultrafast neutron bursts. We measure up to 2 × 106 fusion neutrons per joule, an increase of about 500 times with respect to flat solid targets, a record yield for joule-level lasers. Moreover, in accordance with simulation predictions, we observe a rapid increase in neutron yield with laser pulse energy. The results will impact nuclear science and high energy density research and can lead to bright ultrafast quasi-monoenergetic neutron point sources for imaging and materials studies.
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Affiliation(s)
- Alden Curtis
- Department of Electrical and Computer Engineering, Colorado State University, Fort Collins, CO, 80523, USA.,Nevada National Security Site, Las Vegas, NV, 89030, USA
| | - Chase Calvi
- Department of Physics, Colorado State University, Fort Collins, CO, 80523, USA
| | - James Tinsley
- Nevada National Security Site, Las Vegas, NV, 89030, USA
| | - Reed Hollinger
- Department of Electrical and Computer Engineering, Colorado State University, Fort Collins, CO, 80523, USA
| | - Vural Kaymak
- Institut für Theoretische Physik, Heinrich-Heine-Universität Düsseldorf, 40225, Düsseldorf, Germany
| | - Alexander Pukhov
- Institut für Theoretische Physik, Heinrich-Heine-Universität Düsseldorf, 40225, Düsseldorf, Germany
| | - Shoujun Wang
- Department of Electrical and Computer Engineering, Colorado State University, Fort Collins, CO, 80523, USA
| | - Alex Rockwood
- Department of Physics, Colorado State University, Fort Collins, CO, 80523, USA
| | - Yong Wang
- Department of Electrical and Computer Engineering, Colorado State University, Fort Collins, CO, 80523, USA
| | - Vyacheslav N Shlyaptsev
- Department of Electrical and Computer Engineering, Colorado State University, Fort Collins, CO, 80523, USA
| | - Jorge J Rocca
- Department of Electrical and Computer Engineering, Colorado State University, Fort Collins, CO, 80523, USA. .,Department of Physics, Colorado State University, Fort Collins, CO, 80523, USA.
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4
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Letts SA, Fearon EM, Buckley SR, Saculla MD, Allison LM, Cook R. Fabrication of Polymer Shells Using a Depolymerizable Mandrel. ACTA ACUST UNITED AC 2017. [DOI: 10.13182/fst28-5-1797] [Citation(s) in RCA: 69] [Impact Index Per Article: 9.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Affiliation(s)
- Stephan A. Letts
- Lawrence Livermore National Laboratory, Livermore, CA 94550 (510)422-4373
| | - Evelyn M. Fearon
- Lawrence Livermore National Laboratory, Livermore, CA 94550 (510)422-4373
| | - Steven R. Buckley
- Lawrence Livermore National Laboratory, Livermore, CA 94550 (510)422-4373
| | - Michael D. Saculla
- Lawrence Livermore National Laboratory, Livermore, CA 94550 (510)422-4373
| | - Leslie M. Allison
- Lawrence Livermore National Laboratory, Livermore, CA 94550 (510)422-4373
| | - Robert Cook
- Lawrence Livermore National Laboratory, Livermore, CA 94550 (510)422-4373
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5
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Merrill FE, Danly CR, Izumi N, Jedlovec D, Fittinghoff DN, Grim GP, Pak A, Park HS, Volegov PL, Wilde CH. A concept to collect neutron and x-ray images on the same line of sight at NIF. THE REVIEW OF SCIENTIFIC INSTRUMENTS 2014; 85:11E614. [PMID: 25430360 DOI: 10.1063/1.4891101] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/04/2023]
Abstract
Neutron and x-ray images are collected at the National Ignition Facility (NIF) to measure the size and shape of inertial confinement fusion implosions. The x-ray images provide a measure of the size and shape of the hot region of the deuterium-tritium fuel while the neutron images provide a measure of the size and shape of the burning plasma. Although these two types of images are collected simultaneously, they are not collected along the same line of sight (LOS). One 14 MeV neutron image is collected on the NIF equator, and two x-ray images are collected along the polar axis and nearly perpendicular to the neutron imaging line of sight on the equator. Both measurements use pinhole apertures to form the images, but existing x-ray imaging provides time-resolved measurements while the neutron images are time-integrated. Detailed comparisons of the x-ray and neutron images can provide information on the fuel assembly, but these studies have been limited because the implosions are not azimuthally symmetric and the images are collected along different LOS. We have developed a conceptual design of a time-integrated x-ray imaging system that could be added to the existing neutron imaging LOS. This new system would allow these detailed studies, providing important information on the fuel assembly of future implosions. Here we present this conceptual design and the expected performance characteristics.
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Affiliation(s)
- F E Merrill
- Los Alamos National Laboratory, Los Alamos, New Mexico 87545, USA
| | - C R Danly
- Los Alamos National Laboratory, Los Alamos, New Mexico 87545, USA
| | - N Izumi
- Livermore National Laboratory, Livermore, California 94551, USA
| | - D Jedlovec
- Livermore National Laboratory, Livermore, California 94551, USA
| | - D N Fittinghoff
- Livermore National Laboratory, Livermore, California 94551, USA
| | - G P Grim
- Los Alamos National Laboratory, Los Alamos, New Mexico 87545, USA
| | - A Pak
- Livermore National Laboratory, Livermore, California 94551, USA
| | - H-S Park
- Livermore National Laboratory, Livermore, California 94551, USA
| | - P L Volegov
- Los Alamos National Laboratory, Los Alamos, New Mexico 87545, USA
| | - C H Wilde
- Los Alamos National Laboratory, Los Alamos, New Mexico 87545, USA
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6
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Lötstedt E, Midorikawa K. Nuclear reaction induced by carrier-envelope-phase controlled proton recollision in a laser-driven molecule. PHYSICAL REVIEW LETTERS 2014; 112:093001. [PMID: 24655249 DOI: 10.1103/physrevlett.112.093001] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/16/2013] [Indexed: 06/03/2023]
Abstract
Nuclear reactions induced by proton recollision with a nearby nucleus are studied in a setup where a neutral molecule is exposed to an extremely intense, few-cycle laser pulse. At the rising edge of the laser pulse, all electrons in the molecule are first ejected by field ionization, resulting in a molecule consisting of the bare nuclei only. A proton in the bare molecule is subsequently accelerated by the laser field in such a way that it recollides with a nearby, heavier nucleus, with a kinetic energy high enough to induce a nuclear reaction. As a specific example, the probability of triggering the (15)N(p,α)(12)C reaction by exposing either a (15)NH molecule or a (15)NH3 molecule to an intense laser pulse is calculated using the classical trajectory Monte Carlo method. We show that the proton recollision process can be controlled both by varying the carrier-envelope phase of the laser field and by the degree of molecular orientation. We also find that the magnetic field of the laser pulse plays a crucial role in the recollision dynamics.
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Affiliation(s)
- Erik Lötstedt
- Laser Technology Laboratory, RIKEN, 2-1 Hirosawa, Wako, Saitama 351-0198, Japan and RIKEN Center for Advanced Photonics, 2-1 Hirosawa, Wako, Saitama 351-0198, Japan
| | - Katsumi Midorikawa
- Laser Technology Laboratory, RIKEN, 2-1 Hirosawa, Wako, Saitama 351-0198, Japan and RIKEN Center for Advanced Photonics, 2-1 Hirosawa, Wako, Saitama 351-0198, Japan
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7
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Heidenreich A, Last I, Ron S, Jortner J. Conversion of laser energy to nuclear energy driven by Coulomb explosion of nanostructures. Mol Phys 2013. [DOI: 10.1080/00268976.2013.788746] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
Affiliation(s)
- Andreas Heidenreich
- Department of Chemistry, University of the Basque Country (UPV/EHU) , Donostia, Spain
- Donostia International Physics Center (DIPC) , Donostia, Spain
- IKERBASQUE, Basque Foundation for Science , Bilbao, Spain
| | - Isidore Last
- School of Chemistry, Tel Aviv University , Tel Aviv, Israel
| | - Shlomo Ron
- School of Chemistry, Tel Aviv University , Tel Aviv, Israel
| | - Joshua Jortner
- School of Chemistry, Tel Aviv University , Tel Aviv, Israel
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8
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Cook R. Production of Hollow Microspheres for Inertial Confinement Fusion Experiments. ACTA ACUST UNITED AC 2011. [DOI: 10.1557/proc-372-101] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
Abstract
AbstractThe targets used in inertial confinement fusion (ICF) experiments at the Lawrence Livermore National Laboratory are plastic capsules roughly 0.5 mm in diameter. This paper reviews the fabrication of these capsules, focusing on the production of the thinwalled polystyrene microshell mandrel around which the capsule is built. The relationship between the capsule characteristics, especially surface finish, and capsule performance is discussed, as are the methods of surface characterization and modification necessary for experiments designed to study the effects of surface roughness on implosion dynamics. Targets for the next generation of ICF facilities using more powerful laser drivers will have to be larger while meeting the same or even more stringent symmetry and surface finish requirements. Some of the technologies for meeting these needs are discussed briefly.
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9
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Smalyuk VA, Hu SX, Hager JD, Delettrez JA, Meyerhofer DD, Sangster TC, Shvarts D. Rayleigh-Taylor growth measurements in the acceleration phase of spherical implosions on OMEGA. PHYSICAL REVIEW LETTERS 2009; 103:105001. [PMID: 19792320 DOI: 10.1103/physrevlett.103.105001] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/22/2009] [Indexed: 05/28/2023]
Abstract
The Rayleigh-Taylor (RT) growth of 3D broadband nonuniformities was measured using x-ray radiography in spherical plastic shells accelerated by laser light at an intensity of approximately 2 x 10(14) W/cm(2). The 20- and 24-microm-thick spherical shells were imploded with 54 beams on the OMEGA laser system. The shells contained diagnostic openings for backlighter x rays used to image shell modulations. The measured shell trajectories and modulation RT growth were in fair agreement with 2D hydro simulations during the acceleration phase of the implosions with convergence ratios of up to approximately 2.2. Since the ignition designs rely on these simulations, improvements in the numerical codes will be implemented to achieve better agreement with experiments.
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Affiliation(s)
- V A Smalyuk
- Laboratory for Laser Energetics, University of Rochester, Rochester, New York 14623, USA
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10
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Clark DS, Tabak M. Acceleration- and deceleration-phase nonlinear Rayleigh-Taylor growth at spherical interfaces. PHYSICAL REVIEW. E, STATISTICAL, NONLINEAR, AND SOFT MATTER PHYSICS 2005; 72:056308. [PMID: 16383746 DOI: 10.1103/physreve.72.056308] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/22/2005] [Indexed: 05/05/2023]
Abstract
The Layzer model for the nonlinear evolution of bubbles in the Rayleigh-Taylor instability has recently been generalized to the case of spherically imploding interfaces [D. S. Clark and M. Tabak, Phys. Rev. E 71, 055302(R) (2005)]. The spherical case is more relevant to, e.g., inertial confinement fusion or various astrophysical phenomena when the convergence is strong or the perturbation wavelength is comparable to the interface curvature. Here, the model is further extended to the case of bubble growth during the deceleration (stagnation) phase of a spherical implosion and to the growth of spikes during both the acceleration and deceleration phases. Differences in the nonlinear growth rates for both bubbles and spikes are found when compared with planar results. The model predictions are verified by comparison with numerical hydrodynamics simulations.
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Affiliation(s)
- Daniel S Clark
- Lawrence Livermore National Laboratory, University of California, Livermore, California 94550, USA.
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11
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Shen B, Zhang X, Yu MY. Laser-confined fusion. PHYSICAL REVIEW. E, STATISTICAL, NONLINEAR, AND SOFT MATTER PHYSICS 2005; 71:015401. [PMID: 15697649 DOI: 10.1103/physreve.71.015401] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/27/2004] [Indexed: 05/24/2023]
Abstract
An approach for producing a large quantity of neutrons is proposed. It involves compression of a fuel foil and confinement of the resulting plasma between two intense laser pulses. It is shown that two circularly polarized laser pulses of amplitude a = 7 illuminating a deuterium-tritium foil of areal density 3.3 x 10(18) cm(-2) can produce about 4.2 x 10(6) neutrons per joule of the input laser energy.
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Affiliation(s)
- Baifei Shen
- Shanghai Institute of Optics and Fine Mechanics, P. O. Box 800-211, Shanghai 201800, China
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12
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Regan SP, Delettrez JA, Goncharov VN, Marshall FJ, Soures JM, Smalyuk VA, Radha PB, Yaakobi B, Epstein R, Glebov VY, Jaanimagi PA, Meyerhofer DD, Sangster TC, Seka W, Skupsky S, Stoeckl C, Haynes DA, Frenje JA, Li CK, Petrasso RD, Séguin FH. Dependence of shell mix on feedthrough in direct drive inertial confinement fusion. PHYSICAL REVIEW LETTERS 2004; 92:185002. [PMID: 15169493 DOI: 10.1103/physrevlett.92.185002] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/21/2003] [Indexed: 05/24/2023]
Abstract
The mixing of cold, high-density shell plasma with the low-density, hot spot plasma by the Rayleigh-Taylor instability in inertial confinement fusion is experimentally shown to correlate with the calculated perturbation feedthrough from the ablation surface to the inner shell surface. A fourfold decrease in the density of shell material in the mix region of direct drive implosions of gas filled spherical plastic shells having predicted convergence ratios approximately 15 was observed when laser imprint levels were reduced and the initial shell was thicker, corresponding to a reduction in the feedthrough rms level by a factor of 6. Shell mix is also shown to limit the spherical compression of the implosion.
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Affiliation(s)
- S P Regan
- Laboratory for Laser Energetics, University of Rochester, 250 East River Road, Rochester, NY 14623-1299, USA
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13
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Li CK, Séguin FH, Frenje JA, Kurebayashi S, Petrasso RD, Meyerhofer DD, Soures JM, Delettrez JA, Glebov VY, Radha PB, Regan SP, Roberts S, Sangster TC, Stoeckl C. Effects of fuel-shell mix upon direct-drive, spherical implosions on OMEGA. PHYSICAL REVIEW LETTERS 2002; 89:165002. [PMID: 12398729 DOI: 10.1103/physrevlett.89.165002] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/12/2002] [Indexed: 05/24/2023]
Abstract
Fuel-shell mix and implosion performance are studied for many capsule types in direct-drive experiments at OMEGA. The amount of mixing and the size of the mix region are inferred from charged-particle spectrometry data and confirmed with an experimentally constrained model. Measured yields and convergence ratios CR fall short of one-dimensional predictions, especially for low capsule fill pressures. CR is approximately 11 for pressures from 3 to 15 atm, in contrast to predictions of approximately 25 for 3 atm and approximately 12 for 15 atm. The performance shortfalls are likely to be caused by fuel-shell mix.
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Affiliation(s)
- C K Li
- Plasma Science and Fusion Center, Massachusetts Institute of Technology, Cambridge 02139, USA
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14
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Regan SP, Delettrez JA, Marshall FJ, Soures JM, Smalyuk VA, Yaakobi B, Epstein R, Glebov VY, Jaanimagi PA, Meyerhofer DD, Radha PB, Sangster TC, Seka W, Skupsky S, Stoeckl C, Town RPJ, Haynes DA, Golovkin IE, Hooper CF, Frenje JA, Li CK, Petrasso RD, Séguin FH. Shell mix in the compressed core of spherical implosions. PHYSICAL REVIEW LETTERS 2002; 89:085003. [PMID: 12190476 DOI: 10.1103/physrevlett.89.085003] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/13/2001] [Indexed: 05/23/2023]
Abstract
The Rayleigh-Taylor instability in its highly nonlinear, turbulent stage causes atomic-scale mixing of the shell material with the fuel in the compressed core of inertial-confinement fusion targets. The density of shell material mixed into the outer core of direct-drive plastic-shell spherical-target implosions on the 60-beam, OMEGA laser system is estimated to be 3.4(+/-1.2) g/cm(3) from time-resolved x-ray spectroscopy, charged-particle spectroscopy, and core x-ray images. The estimated fuel density, 3.6(+/-1) g/cm(3), accounts for only approximately 50% of the neutron-burn-averaged electron density, n(e)=2.2(+/-0.4)x10(24) cm(-3).
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Affiliation(s)
- S P Regan
- Laboratory for Laser Energetics, University of Rochester, 250 East River Road, Rochester, New York 14623-1299
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15
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Stygar WA, Olson RE, Spielman RB, Leeper RJ. Analytic models of high-temperature hohlraums. PHYSICAL REVIEW. E, STATISTICAL, NONLINEAR, AND SOFT MATTER PHYSICS 2001; 64:026410. [PMID: 11497714 DOI: 10.1103/physreve.64.026410] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/11/2000] [Indexed: 05/23/2023]
Abstract
A unified set of high-temperature-hohlraum models has been developed. For a simple hohlraum, P(S)=[A(S)+(1-alpha(W))A(W)+A(H)]sigmaT(4)(R)+(4Vsigma/c)(dT(4)(R)/dt), where P(S) is the total power radiated by the source, A(S) is the source area, A(W) is the area of the cavity wall excluding the source and holes in the wall, A(H) is the area of the holes, sigma is the Stefan-Boltzmann constant, T(R) is the radiation brightness temperature, V is the hohlraum volume, and c is the speed of light. The wall albedo alpha(W) identical with(T(W)/T(R))(4) where T(W) is the brightness temperature of area A(W). The net power radiated by the source P(N)=P(S)-A(S)sigmaT(4)(R), which suggests that for laser-driven hohlraums the conversion efficiency eta(CE) be defined as P(N)/P(Laser). The characteristic time required to change T(4)(R) in response to a change in P(N) is 4V/c[(1-alpha(W))A(W)+A(H)]. Using this model, T(R), alpha(W), and eta(CE) can be expressed in terms of quantities directly measurable in a hohlraum experiment. For a steady-state hohlraum that encloses a convex capsule, P(N)=[(1-alpha(W))A(W)+A(H)+[(1-alpha(C))A(C)(A(S)+alpha(W)A(W))/A(T)]]sigmaT(4)(RC), where alpha(C) is the capsule albedo, A(C) is the capsule area, A(T) identical with(A(S)+A(W)+A(H)), and T(RC) is the brightness temperature of the radiation that drives the capsule. According to this relation, the capsule-coupling efficiency of the baseline National Ignition Facility hohlraum is 15-23 % higher than predicted by previous analytic expressions. A model of a hohlraum that encloses a z pinch is also presented.
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Affiliation(s)
- W A Stygar
- Sandia National Laboratories, MS 1194, Albuquerque, New Mexico 87185-1194, USA
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16
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Ditmire T, Zweiback J, Yanovsky VP, Cowan TE, Hays G, Wharton KB. Nuclear fusion from explosions of femtosecond laser-heated deuterium clusters. Nature 1999. [DOI: 10.1038/19037] [Citation(s) in RCA: 662] [Impact Index Per Article: 26.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
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17
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Cauble R, Barbee TW, Celliers P, Decker C, London RA, Moreno JC, Trebes JE, Wan AS, Weber F. Simultaneous Measurement of Local Gain and Electron Density in X-ray Lasers. Science 1996; 273:1093-6. [PMID: 8688093 DOI: 10.1126/science.273.5278.1093] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/01/2023]
Abstract
X-ray lasers (XRLs) have experimental average gains that are significantly less than calculated values and a persistently low level of spatial coherence. An XRL has been used both as an injected signal to a short XRL amplifier and as an interferometer beam to measure two-dimensional local gain and density profiles of the XRL plasma with a resolution near 1 micrometer. The measured local gain is in agreement with atomic models but is unexpectedly spatially inhomogeneous. This inhomogeneity is responsible for the low level of spatial coherence observed and helps explain the disparity between observed and simulated gains.
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Affiliation(s)
- R Cauble
- Lawrence Livermore National Laboratory, University of California, Livermore, CA 94550, USA
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18
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Shepard TD, Back CA, Kalantar DH, Kauffman RL, Keane CJ, Klem DE, Lasinski BF, MacGowan BJ, Powers LV, Suter LJ, Turner RE, Failor BH, Hsing WW. Isoelectronic x-ray spectroscopy to determine electron temperatures in long-scale-length inertial-confinement-fusion plasmas. PHYSICAL REVIEW. E, STATISTICAL PHYSICS, PLASMAS, FLUIDS, AND RELATED INTERDISCIPLINARY TOPICS 1996; 53:5291-5301. [PMID: 9964860 DOI: 10.1103/physreve.53.5291] [Citation(s) in RCA: 21] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
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19
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Haynes DA, Garber DT, Hooper CF, Mancini RC, Lee YT, Bradley DK, Delettrez J, Epstein R, Jaanimagi PA. Effects of ion dynamics and opacity on Stark-broadened argon line profiles. PHYSICAL REVIEW. E, STATISTICAL PHYSICS, PLASMAS, FLUIDS, AND RELATED INTERDISCIPLINARY TOPICS 1996; 53:1042-1050. [PMID: 9964340 DOI: 10.1103/physreve.53.1042] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/22/2023]
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Rosenfeld Y, Nardi E, Zinamon Z. Corresponding states hard-sphere model for the diffusion coefficients of binary dense-plasma mixtures. PHYSICAL REVIEW LETTERS 1995; 75:2490-2493. [PMID: 10059325 DOI: 10.1103/physrevlett.75.2490] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
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Kauffman RL, Suter LJ, Darrow CB, Kilkenny JD, Kornblum HN, Montgomery DS, Phillion DW, Rosen MD, Theissen AR, Wallace RJ, Ze F. High temperatures in inertial confinement fusion radiation cavities heated with 0.35 microm light. PHYSICAL REVIEW LETTERS 1994; 73:2320-2323. [PMID: 10057030 DOI: 10.1103/physrevlett.73.2320] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
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