Plastic deformation of solid hydrogen in fusion targets

Kozioziemski, B.; Kucheyev, S. O.; Lugten, J. B.; Koch, J.; Moody, J. D.; Chernov, A. A.; Mapoles, E. A.; Hamza, A. V.; Atherton, L. J.

doi:10.1063/1.3124362

Cited by 21 publications

(4 citation statements)

References 20 publications

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“…Analysis of the crystalline structure shows this ice layer to be hexagonally close-packed. 6 In this ice configuration heat is conducted radially out of the sphere along the a plane of the crystal over most of the sphere, and along the c axis over the remainder of the sphere. Should the thermal conduction along the c axis and the a plane be significantly different, the ice layer would have an intrinsic limit as to how uniform it could be.…”

Section: Introductionmentioning

confidence: 99%

Thermal conductivity of solid deuterium by the 3ω method

Gram

She

Craxton

et al. 2012

Journal of Applied Physics

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The thermal conductivity of solid D2 is measured by the 3ω method, in which a wire embedded in the medium serves as both a heater and a temperature sensor. Conductivity values are obtained by fitting experimental data with a two-dimensional model that calculates heat flow in both the axial and radial directions as a function of frequency. The model provides the thermal conductivity of D2 from the measurement of the 3ω voltage and published values of specific heat and density of D2 and of the sensor wire, and thermal conductivity values for the sensor wire. Data for D2 gas and liquid are obtained for comparison to solid D2. Conductivity values obtained for solid D2 range from 0.35 ± 0.01 W/(m K) at 18.6 K to 0.75 ± 0.02 W/(m K) at 13.4 K and are the same for normal and ortho D2. These values are acquired at lower temperatures than the 3ω method has previously been used for.

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Section: Introductionmentioning

confidence: 99%

Thermal conductivity of solid deuterium by the 3ω method

Gram

She

Craxton

et al. 2012

Journal of Applied Physics

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“…the crystal seed) is left in tube. Gently releasing the heater power will cool the capsule again and lead to expected single crystal growing [36][37][38][39][40][41][42]. The capsule thermal field in this procedure is quasistable because the temperature varying rate at the cylinder ends is about 1 mK min −1 .…”

Section: Verification By a Cryogenic Dd Experimentsmentioning

confidence: 99%

Predicting spherical symmetry degeneration of non-infrared deuterium ice layer in a cryogenic capsule

et al. 2020

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A cylindrical cryogenic target containing deuterium fuel acts as an important surrogate to help understand implosion physics before the deuterium-tritium capability is brought online. Uniformity of the deuterium ice thickness is a key parameter for the inertial confinement fusion (ICF) experiments. Achieving and retaining a uniform deuterium ice layer in capsule without infrared radiation is difficult in engineering. The method used to calculate the ice thickness deviation of deuterium-tritium fuel is invalid when the bulk heat generation is equal to zero. Appearance solutions of the deuterium ice in steady state conclude that a uniform ice layer cannot be retained for long without infrared radiation. A transient algorithm by integrating heat transfer theory, the equation derived from Stefan problem and mass conservation with moving mesh technics in a finite element model can be applied to predict deuterium ice spherical symmetry degeneration. It is certified with good reliability by comparing the simulated results with theoretical and experimental data. As for the deuterium targets, the characteristics of linear approximation and integrability avert heavy work of moving mesh in analyses of stable and unstable scenarios. The work has great support for the cryogenic processing and engineering design of ICF targets.

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“…These and related issues are discussed in Refs. 721,722,729,and 730. Compounding this complexity is the heat load to the target from thermal radiation and b-decay once the shrouds are retracted and the target is exposed without any conductive gas surrounding it to remove this heat. These effects are being studied using surrogate target designs that allow the results to be extrapolated to actual targets.…”

Section: Ice-layer Characterizationmentioning

confidence: 99%

Direct-drive inertial confinement fusion: A review

et al. 2015

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The direct-drive, laser-based approach to inertial confinement fusion (ICF) is reviewed from its inception following the demonstration of the first laser to its implementation on the present generation of high-power lasers. The review focuses on the evolution of scientific understanding gained from target-physics experiments in many areas, identifying problems that were demonstrated and the solutions implemented. The review starts with the basic understanding of laser–plasma interactions that was obtained before the declassification of laser-induced compression in the early 1970s and continues with the compression experiments using infrared lasers in the late 1970s that produced thermonuclear neutrons. The problem of suprathermal electrons and the target preheat that they caused, associated with the infrared laser wavelength, led to lasers being built after 1980 to operate at shorter wavelengths, especially 0.35 μm—the third harmonic of the Nd:glass laser—and 0.248 μm (the KrF gas laser). The main physics areas relevant to direct drive are reviewed. The primary absorption mechanism at short wavelengths is classical inverse bremsstrahlung. Nonuniformities imprinted on the target by laser irradiation have been addressed by the development of a number of beam-smoothing techniques and imprint-mitigation strategies. The effects of hydrodynamic instabilities are mitigated by a combination of imprint reduction and target designs that minimize the instability growth rates. Several coronal plasma physics processes are reviewed. The two-plasmon–decay instability, stimulated Brillouin scattering (together with cross-beam energy transfer), and (possibly) stimulated Raman scattering are identified as potential concerns, placing constraints on the laser intensities used in target designs, while other processes (self-focusing and filamentation, the parametric decay instability, and magnetic fields), once considered important, are now of lesser concern for mainline direct-drive target concepts. Filamentation is largely suppressed by beam smoothing. Thermal transport modeling, important to the interpretation of experiments and to target design, has been found to be nonlocal in nature. Advances in shock timing and equation-of-state measurements relevant to direct-drive ICF are reported. Room-temperature implosions have provided an increased understanding of the importance of stability and uniformity. The evolution of cryogenic implosion capabilities, leading to an extensive series carried out on the 60-beam OMEGA laser [Boehly et al., Opt. Commun. 133, 495 (1997)], is reviewed together with major advances in cryogenic target formation. A polar-drive concept has been developed that will enable direct-drive–ignition experiments to be performed on the National Ignition Facility [Haynam et al., Appl. Opt. 46(16), 3276 (2007)]. The advantages offered by the alternative approaches of fast ignition and shock ignition and the issues associated with these concepts are described. The lessons learned from target-physics and implosion experiments are taken into account in ignition and high-gain target designs for laser wavelengths of 1/3 μm and 1/4 μm. Substantial advances in direct-drive inertial fusion reactor concepts are reviewed. Overall, the progress in scientific understanding over the past five decades has been enormous, to the point that inertial fusion energy using direct drive shows significant promise as a future environmentally attractive energy source.

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Plastic deformation of solid hydrogen in fusion targets

Cited by 21 publications

References 20 publications

Thermal conductivity of solid deuterium by the 3ω method

Thermal conductivity of solid deuterium by the 3ω method

Predicting spherical symmetry degeneration of non-infrared deuterium ice layer in a cryogenic capsule

Direct-drive inertial confinement fusion: A review

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