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Study of the asymmetry of hot-spot self-emission imaging of inertial confinement fusion implosion driven by high-power laser facilities

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Plasma Science and Technology 2020年第8期22卷 20-26页

作者：董云松康洞国蒋炜刘志诚陈忠靖张兴李欣孙传奎尹传盛董建军杨志文蒲昱东晏骥余波黄天晅缪文勇戴振生葛峰峻杨冬王峰杨家敏江少恩 Research Center of Laser Fusion Chinese Academy of Engineering PhysicsMianyang 621900People's Republic of China Institute of Applied Physics and Computational Mathematics Beijing 100088People's Republic of China Department of Engineering Physics Tsinghua UniversityBeijing 100086People's Republic of China

Implosion asymmetry is a crucial problem quenching ignition in the field of inertial confinement fusion.A forward-calculation method based on 1D and 2D hydrodynamic simulations has been developed to generate and study the x-ray images of hot-spot self-emission,indicating asymmetry integrated over the entire drive pulse.It is shown that the x-ray imaging photon energy should be higher to avoid the influence of the remaining shell.The contour level(percentage of the maximum emission intensity)and spatial resolution should be as low as possible,optimally less than 20%and 3μm,for characterization of higher-mode signatures such as Ps-P12 by x-ray self-emission images.On the contrary,signatures of lower-mode such as P2 remain clear at all contour levels and spatial resolutions.These key results can help determine the optimal diagnostics,laser,and target parameters for implosion experiments.Recent typical hot-spot asymmetry measurements and applications on the Shenguang 100 kJ class laser facility are also reported.

关键词： inertial confinement fusion implosion x-ray self-emission hot-spot asymmetry

Upper ocean near-inertial response to the passage of two sequential typhoons in the northwestern South China Sea

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Science China Earth Sciences 2019年第5期62卷 863-871页

作者： Yonggui MA Shuwen ZHANG Yiquan QI Zhiyou JING College of Ocean and Meteorology Guangdong Ocean University Laboratory for Regional Oceanography and Numerical Modeling Qingdao National Laboratory for Marine Science and Technology College of Oceanography Hohai University State Key Laboratory of Tropical Oceanography South China Sea Institute of OceanologyChinese Academy of Sciences

Fifty-seven days of moored current records are examined, focusing on the sequential passage of Typhoons Nesat and Nalgae separated by 5 days in the northwestern South China Sea. Both typhoons generated strong near-inertial waves(NIW) as detected by a moored array, with the near-inertial velocity to the right of the typhoon path significantly larger than to the left. The estimated vertical phase and group velocities of the NIW induced by Typhoon Nesat are 0.2 cm s^(-1) and 0.85 m h^(-1), respectively,corresponding to a vertical wavelength of 350 m. Both the vertical phase and group velocities of the NIW induced by Typhoon Nalgae are lower than those of Typhoon Nesat, with the corresponding vertical wavelength only one-half that of Nesat. The threshold values of induced near-inertial kinetic energy(NIKE) of 5 J m^(-3) reach water depths of 300 and 200 m for Typhoons Nesat and Nalgae, respectively, illustrating that the NIKE induced by Typhoon Nesat dissipated less with depth. Obvious blueshifts in the induced NIW frequencies are also detected. The frequency of NIW induced by Typhoon Nesat significantly increases at water depths of 100–150 m because of Doppler shifting, but decreases significantly at water depths of 100–150 m for Nalgae because of the greater influence of the background vorticity during the passage of Typhoon Nalgae.

关键词： Typhoon Nesat Typhoon Nalgae Near-inertial waves Near-inertial kinetic energy inertial wave propagation

Fully enclosed multi-axis inertial reaction mechanisms for wave energy conversion

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Journal of Ocean Engineering and Science 2017年第1期2卷 5-17页

作者： I.A.Antoniadis V.Georgoutsos A.Paradeisiotis Mechanical Design and Control Systems Section Mechanical Engineering DepartmentNational Technical University of AthensHeroon Polytechniou 9Zografou 15780Greece

This paper introduces a novel concept for wave energy conversion,using fully enclosed appropriate internal body configurations,which provide inertial reaction against the motion of an external vessel.In this way,reliability,robustness and survivability under extreme weather conditions-a fundamental prerequisite for wave energy converters-can be achieved.Acting under the excitation of the waves,the external vessel is subjected to a simultaneous surge and pitch motion in all directions,ensuring maximum wave energy capture in comparison to other wave energy converters like point heave absorbers.The internal body is suspended from the external vessel body in such an appropriate geometrical configuration,that a symmetric four-bar mechanism is essentially formed.The main advantage of this suspension geometry is that a linear trajectory results for the centre of the mass of the suspended body with respect to the external vessel,enabling the introduction of a quite simple form of a Power Take Off(PTO)design.Thus,because of this simplicity and symmetry of the suspension geometry and of the PTO mechanism,the fundamental restrictions of other linear,pendulum or gyroscopic variants on inertial reacting bodies are significantly removed.

关键词： Waves Energy inertial Pendulum Platforms Offshore

Temperature dependence of parametric instabilities in the context of the shock-ignition approach to inertial confinement fusion

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High Power Laser Science and Engineering 2015年第1期3卷 51-63页

作者： S.Weber C.Riconda Institute of Physics of the ASCR ELI-Beamlines LULI Sorbonne Universités - Université Pierre et Marie Curie - Ecole Polytechnique - CNRS - CEA

The role of the coronal electron plasma temperature for shock-ignition conditions is analysed with respect to the dominant parametric processes: stimulated Brillouin scattering, stimulated Raman scattering, two-plasmon decay(TPD), Langmuir decay instability(LDI) and cavitation. TPD instability and cavitation are sensitive to the electron temperature. At the same time the reflectivity and high-energy electron production are strongly affected. For low plasma temperatures the LDI plays a dominant role in the TPD saturation. An understanding of laser–plasma interaction in the context of shock ignition is an important issue due to the localization of energy deposition by collective effects and hot electron production.This in turn can have consequences for the compression phase and the resulting gain factor of the implosion phase.

关键词： inertial confinement fusion shock ignition laser–plasma interaction parametric instabilities

Existence and Blow-up of Smooth Solutions for Cahn-Hilliard Equation with inertial Term

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Journal of Donghua University(English Edition) 2019年第4期36卷 413-420页

作者：丁蓉吴志刚 College of Science Donghua University

The motivation of this paper is to systematically study how the inertial term affects the behavior of the solution of the Cahn-Hilliard equation.When there is an inertial term,the equation becomes a parabolic-hyperbolic one.To overcome the difficulties from large perturbation and the hyperbolicity,a few elaborate energy estimates should be given,which are based on choosing suitable space of the smooth solution,even some inequalites in negative Sobolev space.More precisely,for 1-dimensional(1D)non-viscous case and 1D,2D,and 3D viscous case,the global existence of the smooth solutions are given.Moreover,several blow-up results are established by using the convex method.The results exhibit the interplay between the viscosity and the inertial term for the behavior of the smooth solution.

关键词： Cahn-Hilliard equation with inertial term existence blow-up

inertial confinement fusion and prospects for power production

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High Power Laser Science and Engineering 2015年第1期3卷 36-43页

作者： C.B.Edwards C.N.Danson HiPER Project STFC Rutherford Appleton Laboratory AWE plc

As our understanding of the environmental impact of fossil fuel based energy production increases, it is becoming clear that the world needs a new energy solution to meet the challenges of the future. A transformation is required in the energy market to meet the need for low carbon, sustainable, affordable generation matched with security of supply. In the short term, an increasing contribution from renewable sources may provide a solution in some locations. In the longer term,low carbon, sustainable solutions must be developed to meet base load energy demand, if the world is to avoid an ever increasing energy gap and the attendant political instabilities. Laser-driven inertial fusion energy(IFE) may offer such a solution.

关键词： ICF IFE inertial confinement fusion inertial fusion energy

inertial measurement using atom interferometry

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Instrumentation 2015年第4期2卷 56-66页

作者： JIA Aiai YANG Jun YAN Shuhua LUO Yukun HU Qingqing WEI Chunhua LI Zehuan College of Mechatronic Engineering and Automation National University of Defense Technology Interdisciplinary Center for Quantum Information National University of Defense Technology

The recent advances of atom interferometer and its application in precision inertial measurement are review ed. The principle,characteristics and implementation of atom interferometer are introduced and it can be used to measure gravitational acceleration,gravity gradient and rotation for its high sensitivity. We also present the principle,structure and new progress of gravimeter,gravity gradiometer and gyroscope based on atom interferometer.

关键词： atom interferometer inertial measurement gravity rotation

A Survey of the Research Status of Pedestrian Dead Reckoning Systems Based on inertial Sensors

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International Journal of Automation and computing 2019年第1期16卷 65-83页

作者： Yuan Wu Hai-Bing Zhu Qing-Xiu Du Shu-Ming Tang Institute of Automation Chinese Academy of Sciences University of Chinese Academy of Sciences

With the development of micro-electromechanical systems(MEMS), miniaturized, low-power and low-cost inertial measurement units(IMUs) have been widely integrated into mobile terminals and smart wearable devices. This provides the prospect of a broad application for the inertial sensor-based pedestrian dead-reckoning(IPDR) systems. Especially for indoor navigation and indoor positioning, the IPDR systems have many unique advantages that other methods do not have. At present, a large number of technologies and methods for IPDR systems are proposed. In this paper, we have analyzed and outlined the IPDR systems based on about 80 documents in the field of IPDR in recent years. The article is structured in the form of an introduction-elucidation-conclusion framework. First, we proposed a general framework to explore the structure of an IPDR system. Then, according to this framework, the IPDR system was divided into six relatively independent sub-problems, which were discussed and summarized separately. Finally, we proposed a graph structure of IPDR systems, and a sub-directed graph, formed by selecting a combined path from the start node to the end node, skillfully constitutes a technical route of one specific IPDR system. At the end of the article, we summarized some key issues that need to be resolved before the IPDR systems are widely used.

关键词： inertial measurement unit(IMU) pedestrian dead-reckoning indoor navigation technical route general framework

Permeation fill-tube design for inertial confinementfusion target capsules

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High Power Laser Science and Engineering 2017年第1期5卷 34-40页

作者： B.S.Rice J.Ulreich C.Fella J.Crippen P.Fitzsimmons A.Nikroo Rochester Institute of Technology 78 Lomb Memorial DriveRochesterNY 14623-5604USA Laboratory for Laser Energetics University of Rochester250 East River RoadRochesterNY 14623-1299USA General Atomics San DiegoCA 92186USA Lawrence Livermore National Laboratory LivermoreCA 94550USA

A unique approach for permeation filling of nonpermeable inertial confinement fusion target capsules with deuterium–tritium(DT) is presented. This process uses a permeable capsule coupled into the final target capsule with a 0.03-mmdiameter fill tube. Leak free permeation filling of glow-discharge polymerization(GDP) targets using this method have been successfully demonstrated, as well as ice layering of the target, yielding an inner ice surface roughness of 1-μm rms(root mean square). Finally, the measured DT ice-thickness profile for this experiment was used to validate a thermal model's prediction of the same thickness profile.

关键词： fill-tube inertial confinement fusion permeation fill target capsule