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Finite Difference Simulation of Implosive Collapsing for Aluminum Spherical Shell
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作者 Weicheng Bi Banghai Jiang Chenglong Han 《Journal of Applied Mathematics and Physics》 2018年第8期1606-1613,共8页
Implosive collapsing for spherical metal shells is a kind of dynamic compressing method, in which high pressure and high compression degree of materials can be attained. In present work, the dynamic process of implosi... Implosive collapsing for spherical metal shells is a kind of dynamic compressing method, in which high pressure and high compression degree of materials can be attained. In present work, the dynamic process of implosive collapsing for spherical metal shells was regard as spherical symmetry ideally, so one-dimensional spherical symmetric fluid dynamics conservation equations were established, and the finite difference schemes for solving these equations were given. An aluminum spherical shell was assumed, whose inner radius is 4cm and thickness is 2 cm. In numerical simulation, initial centripetal velocities (800, 1000 and 1200 m/s) were used to make aluminum spherical shell collapse. The simulation results show that during the process of implosive collapsing, the material exhibits a compression-expansion-compression pulsation process, and the internal pressure changes and distribution are consistent with the theoretical expectations. The simulation results can be used as a reference for relevant analysis. 展开更多
关键词 implosive COLLAPSE SPHERICAL SHELL Finite DIFFERENCE Numerical SIMULATION
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DETONATION INITIATION INDUCED BY FLAME IMPLOSION AND SHOCK WAVE FOCUSING 被引量:2
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作者 秦亚欣 于军力 高歌 《Transactions of Nanjing University of Aeronautics and Astronautics》 EI 2011年第1期57-65,共9页
Computational simulations on structurally different detonation generator are carried out to study the phenomena,the mechanism and the gas dynamics characteristics of flame implosion and shock wave focusing.Two-dimensi... Computational simulations on structurally different detonation generator are carried out to study the phenomena,the mechanism and the gas dynamics characteristics of flame implosion and shock wave focusing.Two-dimensional axisymmetric and unsteady Navier-Stokes equations are numerically solved and detailed chemical reaction kinetics of hydrogen/air mixture is used.The simulation results show that the laminar flame generated by low energy spark in the jet flame burner is accelerated under the narrow channel,the jet flame impinging on the axis strengthens shock wave and the shock wave enhances flame acceleration.Under the function of multiple shock waves and flame,a number of hot spots appear between the wave and the surface.The spots enlarge rapidly,thus forming an over-drive detonation with high pressure,and then declining to stable detonation.Through calculation and analysis,the length of detonation initiation and stable detonation are obtained,thus providing the useful information for further experimental investigations. 展开更多
关键词 DETONATION shock wave focusing flame implosion deflagration-to-detonation
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Review of heavy-ion inertial fusion physics 被引量:10
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作者 S.Kawata T.Karino A.I.Ogoyski 《Matter and Radiation at Extremes》 SCIE EI CAS 2016年第2期89-113,共25页
In this review paper on heavy ion inertial fusion(HIF),the state-of-the-art scientific results are presented and discussed on the HIF physics,including physics of the heavy ion beam(HIB)transport in a fusion reactor,t... In this review paper on heavy ion inertial fusion(HIF),the state-of-the-art scientific results are presented and discussed on the HIF physics,including physics of the heavy ion beam(HIB)transport in a fusion reactor,the HIBs-ion illumination on a direct-drive fuel target,the fuel target physics,the uniformity of the HIF target implosion,the smoothing mechanisms of the target implosion non-uniformity and the robust target implosion.The HIB has remarkable preferable features to release the fusion energy in inertial fusion:in particle accelerators HIBs are generated with a high driver efficiency of~30%-40%,and the HIB ions deposit their energy inside of materials.Therefore,a requirement for the fusion target energy gain is relatively low,that would be~50-70 to operate a HIF fusion reactor with the standard energy output of 1 GWof electricity.The HIF reactor operation frequency would be~10-15 Hz or so.Several-MJ HIBs illuminate a fusion fuel target,and the fuel target is imploded to about a thousand times of the solid density.Then the DT fuel is ignited and burned.The HIB ion deposition range is defined by the HIB ions stopping length,which would be~1 mm or so depending on the material.Therefore,a relatively large density-scale length appears in the fuel target material.One of the critical issues in inertial fusion would be a spherically uniform target compression,which would be degraded by a non-uniform implosion.The implosion non-uniformity would be introduced by the Rayleigh-Taylor(R-T)instability,and the large densitygradient-scale length helps to reduce the R-T growth rate.On the other hand,the large scale length of the HIB ions stopping range suggests that the temperature at the energy deposition layer in a HIF target does not reach a very-high temperature:normally about 300 eV or so is realized in the energy absorption region,and that a direct-drive target would be appropriate in HIF.In addition,the HIB accelerators are operated repetitively and stably.The precise control of the HIB axis manipulation is also realized in the HIF accelerator,and the HIB wobbling motion may give another tool to smooth the HIB illumination non-uniformity.The key issues in HIF physics are also discussed and presented in the paper. 展开更多
关键词 Heavy ion inertial fusion Heavy ion fusion reactor system Fusion fuel target implosion Implosion dynamics Heavy ion beam transport Rayleigh-Taylor instability stabilization Robust fusion system
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Numerical study on magneto-Rayleigh–Taylor instabilities for thin liner implosions on the primary test stand facility 被引量:3
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作者 Xiao-Guang Wang Shun-Kai Sun +8 位作者 De-Long Xiao Guan-Qiong Wang Yang Zhang Shao-Tong Zhou Xiao-Dong Ren Qiang Xu Xian-Bin Huang Ning Ding Xiao-Jian Shu 《Chinese Physics B》 SCIE EI CAS CSCD 2019年第3期256-264,共9页
The thin aluminum liners with an aspect ratio R/?r 1 have been imploded on the primary test stand(PTS) facility,where R is the outer radius of the liner and ?r is the thickness. The x-ray self-emission images present ... The thin aluminum liners with an aspect ratio R/?r 1 have been imploded on the primary test stand(PTS) facility,where R is the outer radius of the liner and ?r is the thickness. The x-ray self-emission images present azimuthally correlated perturbations in the liner implosions. The experiments show that at-10 ns before the stagnation, the wavelengths of perturbation are about 0.93 mm and 1.67 mm for the small-radius and large-radius liners, respectively. We have utilized the resistive magnetohydrodynamic code PLUTO to study the development of magneto-Rayleigh–Taylor(MRT) instabilities under experimental conditions. The calculated perturbation amplitudes are consistent with the experimental observations very well. We have found that both mode coupling and long implosion distance are responsible for the more developed instabilities in the large-radius liner implosions. 展开更多
关键词 magneto-Rayleigh–Taylor instability thin liner implosion Z-PINCHES magnetohydrodynamic(MHD) PRIMARY test stand(PTS)
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Assembling Stabilization of the Rayleigh-Taylor Instability by the Effects of Finite Larmor Radius and Sheared Axial Flow 被引量:3
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作者 简广德 黄林 邱孝明 《Plasma Science and Technology》 SCIE EI CAS CSCD 2005年第3期2805-2809,共5页
The assembling stabilizing effect of the finite Larmor radius (FLR) and the sheared axial flow (SAF) on the Rayleigh-Taylor instability in Z-pinch implosions is studied by means of the incompressible finite Larmor rad... The assembling stabilizing effect of the finite Larmor radius (FLR) and the sheared axial flow (SAF) on the Rayleigh-Taylor instability in Z-pinch implosions is studied by means of the incompressible finite Larmor radius magnetohydrodynamic (MHD) equations. The finite Larmor radius effects are introduced in the momentum equation with the sheared axial flow through an anisotropic ion stress tensor. In this paper a linear mode equation is derived that is valid for arbitrary kL, where k is the wave number and L is the plasma shell thickness. Numerical solutions are presented. The results indicate that the short-wavelength modes of the Rayleigh-Taylor instability are easily stabilized by the individual effect of the finite Larmor radius or the sheared axial flow. The assembling effects of the finite Larmor radius and sheared axial flow can heavily mitigate the Rayleigh-Taylor instability, and the unstable region can be compressed considerably. 展开更多
关键词 Z-PINCH IMPLOSION rayleigh-taylor instability finite larmor radius
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P2 asymmetry of Au's M-band flux and its smoothing effect due to high-Z ablator dopants 被引量:2
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作者 Yongsheng Li Chuanlei Zhai +6 位作者 Guoli Ren Jianfa Gu Wenyi Huo Xujun Meng Wenhua Ye Ke Lan Weiyan Zhang 《Matter and Radiation at Extremes》 SCIE EI CAS 2017年第2期69-76,共8页
X-ray drive asymmetry is one of the main seeds of low-mode implosion asymmetry that blocks further improvement of the nuclear per-formance of“high-foot”experiments on the National Ignition Facility[Miller et al.,Nuc... X-ray drive asymmetry is one of the main seeds of low-mode implosion asymmetry that blocks further improvement of the nuclear per-formance of“high-foot”experiments on the National Ignition Facility[Miller et al.,Nucl.Fusion 44,S228(2004)].More particularly,the P2 asymmetry of Au's M-band flux can also severely influence the implosion performance of ignition capsules[Li et al.,Phys.Plasmas 23,072705(2016)].Here we study the smoothing effect of mid-and/or high-Z dopants in ablator on Au's M-band flux asymmetries,by modeling and comparing the implosion processes of a Ge-doped ignition capsule and a Si-doped one driven by X-ray sources with P2 M-band flux asymmetry.As the results,(1)mid-or high-Z dopants absorb hard X-rays(M-band flux)and re-emit isotropically,which helps to smooth the asymmetric M-band flux arriving at the ablation front,therefore reducing the P2 asymmetries of the imploding shell and hot spot;(2)the smoothing effect of Ge-dopant is more remarkable than Si-dopant because its opacity in Au's M-band is higher than the latter's;and(3)placing the doped layer at a larger radius in ablator is more efficient.Applying this effect may not be a main measure to reduce the low-mode implosion asymmetry,but might be of significance in some critical situations such as inertial confinement fusion(ICF)experiments very near the performance cliffs of asymmetric X-ray drives. 展开更多
关键词 Inertial confinement fusion IMPLOSION Low-mode distortion M-band flux asymmetry High-Z dopant
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Effects of mode coupling between low-mode radiation flux asymmetry and intermediate-mode ablator roughness on ignition capsule implosions 被引量:2
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作者 Jianfa Gu Zhensheng Dai +4 位作者 Shiyang Zou Wenhua Ye Wudi Zheng Peijun Gu Shaoping Zhu 《Matter and Radiation at Extremes》 SCIE EI CAS 2017年第1期9-15,共7页
The low-mode shell asymmetry and high-mode hot spot mixing appear to be the main reasons for the performance degradation of the National Ignition Facility(NIF)implosion experiments.The effects of the mode coupling bet... The low-mode shell asymmetry and high-mode hot spot mixing appear to be the main reasons for the performance degradation of the National Ignition Facility(NIF)implosion experiments.The effects of the mode coupling between low-mode P2 radiation flux asymmetry and intermediate-mode L=24 capsule roughness on the implosion performance of ignition capsule are investigated by two-dimensional radiation hydrodynamic simulations.It is shown that the amplitudes of new modes generated by the mode coupling are in good agreement with the second-order mode coupling equation during the acceleration phase.The later flow field not only shows large areal density P2 asymmetry in the main fuel,but also generates large-amplitude spikes and bubbles.In the deceleration phase,the increasing mode coupling generates more new modes,and the perturbation spectrum on the hot spot boundary is mainly from the strong mode interactions rather than the initial perturbation conditions.The combination of the low-mode and high-mode perturbations breaks up the capsule shell,resulting in a significant reduction of the hot spot temperature and implosion performance. 展开更多
关键词 Mode coupling Low-mode drive asymmetry Intermediate-mode capsule roughness Ignition capsule implosion
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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 被引量:1
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作者 Yunsong DONG Dongguo KANG +19 位作者 Wei JIANG Zhicheng LIU Zhongjing CHEN Xing ZHANG Xin LI Chuankui SUN Chuansheng YIN Jianjun DONG Zhiwen YANG Yudong PU Ji YAN Bo YU Tianxuan HUANG Wenyong MIAO Zhensheng DAI Fengjun GE Dong YANG Feng WANG Jiamin YANG Shaoen JIANG 《Plasma Science and Technology》 SCIE EI CAS CSCD 2020年第8期20-26,共7页
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... 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. 展开更多
关键词 INERTIAL CONFINEMENT FUSION IMPLOSION x-ray self-emission HOT-SPOT asymmetry
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Diagnostic technique for measuring fusion reaction rate for inertial confinement fusion experiments at Shen Guang-III prototype laser facility 被引量:1
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作者 王峰 彭晓世 +2 位作者 康洞国 刘慎业 徐涛 《Chinese Physics B》 SCIE EI CAS CSCD 2013年第11期401-405,共5页
A study is conducted using a two-dimensional simulation program (Lared-s) with the goal of developing a technique to evaluate the effect of Rayleigh-Taylor growth in a neutron fusion reaction region. Two peaks of fu... A study is conducted using a two-dimensional simulation program (Lared-s) with the goal of developing a technique to evaluate the effect of Rayleigh-Taylor growth in a neutron fusion reaction region. Two peaks of fusion reaction rate are simulated by using a two-dimensional simulation program (Lared-s) and confirmed by the experimental results. A neutron temporal diagnostic (NTD) system is developed with a high temporal resolution of - 30 ps at the Shen Guang-Ⅲ (SG-Ⅲ) prototype laser facility in China, to measure the fusion reaction rate history. With the shape of neutron reaction rate curve and the spherical harmonic function in this paper, the degree of Rayleigh-Taylor growth and the main source of the neutron yield in our experiment can be estimated qualitatively. This technique, including the diagnostic system and the simulation program, may provide important information for obtaining a higher neutron yield in implosion experiments of inertial confinement fusion. 展开更多
关键词 inertial confinement fusion Rayleigh-Taylor growth neutron fusion reaction IMPLOSION
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DD proton spectrum for diagnosing the areal density of imploded capsules on Shenguang Ⅲ prototype laser facility 被引量:1
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作者 滕建 张天奎 +11 位作者 伍波 蒲昱东 洪伟 单连强 朱斌 何卫华 卢峰 温贤伦 周维民 曹磊峰 江少恩 谷渝秋 《Chinese Physics B》 SCIE EI CAS CSCD 2014年第7期536-540,共5页
The primary DD proton spectrum is used for diagnosing the fuel-shell areal density pR of imploded capsules on Shenguang Ⅲ (SG-Ⅲ) prototype laser facility for the first time. A charged particle spectrometer (CPS)... The primary DD proton spectrum is used for diagnosing the fuel-shell areal density pR of imploded capsules on Shenguang Ⅲ (SG-Ⅲ) prototype laser facility for the first time. A charged particle spectrometer (CPS) with a CR39 nuclear track detector is used to measure the DD proton spectrum. The proton spectrum is determined from both the proton track and its size. A typical proton energy peak shift from 3.02 MeV to 2.6 MeV is observed in our experiment, which yields a maximum pR larger than 6 mg/cm2. 展开更多
关键词 DD proton spectrum charged particle spectrometer areal density IMPLOSION
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Radiation characteristics and implosion dynamics of tungsten wire array Z-pinches on the YANG accelerator 被引量:1
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作者 黄显宾 杨礼兵 +13 位作者 李晶 周少彤 任晓东 张思群 但加坤 蔡红春 段书超 陈光华 章征伟 欧阳凯 李军 张朝辉 周荣国 王贵林 《Chinese Physics B》 SCIE EI CAS CSCD 2012年第5期410-417,共8页
We investigated the radiation characteristics and implosion dynamics of low-wire-number cylindrical tungsten wire array Z-pinches on the YANG accelerator with a peak current 0.8-1.1 MA and a rising time ~ 90 ns.The a... We investigated the radiation characteristics and implosion dynamics of low-wire-number cylindrical tungsten wire array Z-pinches on the YANG accelerator with a peak current 0.8-1.1 MA and a rising time ~ 90 ns.The arrays are made up of(8-32)×5 μm wires 6/10 mm in diameter and 15 mm in height.The highest X-ray power obtained in the experiments was about 0.37 TW with the total radiation energy ~ 13 kJ and the energy conversion efficiency ~ 9%(24×5 μm wires,6 mm in diameter).Most of the X-ray emissions from tungsten Z-pinch plasmas were distributed in the spectral band of 100-600 eV,peaked at 250 and 375 eV.The dominant wavelengths of the wire ablation and the magneto-Rayleigh-Taylor instability were found and analyzed through measuring the time-gated self-emission and laser interferometric images.Through analyzing the implosion trajectories obtained by an optical streak camera,the run-in velocities of the Z-pinch plasmas at the end of the implosion phase were determined to be about(1.3-2.1)×10 7 cm/s. 展开更多
关键词 Z-PINCH tungsten wire array X-ray radiation implosion dynamics
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Comparison Between Mitigation Effects of the Finite Larmor Radius and Sheared Axial Flow on Rayleigh-Taylor Instability in Z-Pinch Implosions 被引量:1
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作者 邱孝明 黄林 简广德 《Plasma Science and Technology》 SCIE EI CAS CSCD 2002年第5期1429-1434,共6页
A magnetohydrodynamic (MHD) formulation is derived to investigate and compare the mitigation effects of both the sheared axial flow and finite Larmor radius (FLR) on the Rayleigh-Taylor (RT) instability in Z-pinch imp... A magnetohydrodynamic (MHD) formulation is derived to investigate and compare the mitigation effects of both the sheared axial flow and finite Larmor radius (FLR) on the Rayleigh-Taylor (RT) instability in Z-pinch implosions. The sheared axial flow is introduced into MHD equations in a conventional way and the FLR effect into the equations via /t → -i(w+ik⊥2pi2Ωi,), as proposed in our previous paper [Chin. Phys. Lett. 2002, 19:217] , where k⊥2 pi2 is referred to FLR effect from the general kinetic theory of magnetized plasma. Therefore the linearized continuity and momentum equations for the perturbed mass-density and velocity include both the sheared axial flow and the FLR effect. It is found that the effect of sheared axial flow with a lower peak velocity can mitigate RT instability in the whole wavenumber region and the effect of sheared axial flow with a higher one can mitigate RT instability only in the large wavenumber region (for normalized wavenumber k】2.4); The effect of FLR can mitigate RT instability in the whole wavenumber region and the mitigation effect is stronger than that of the sheared axial flow with a lower peak velocity in the almost whole wavenumber region. 展开更多
关键词 Z-pinch implosions rayleigh-taylor instability finite larmor radius sheared axial flow. MHD formulation
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Scientometric Implosion that Leads to Explosion: Case Study of Armenian Journals 被引量:1
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作者 Shushanik Sargsyan Edita Gzoyan +1 位作者 Aram Mirzoyan Viktor Blaginin 《Journal of Data and Information Science》 CSCD 2020年第3期187-196,共10页
Purpose: The purpose of this study is to introduce a new concept and term into the scientometric discourse and research—scientometric implosion—and test the idea on the example of the Armenian journals. The article ... Purpose: The purpose of this study is to introduce a new concept and term into the scientometric discourse and research—scientometric implosion—and test the idea on the example of the Armenian journals. The article argues that the existence of a compressed scientific area in the country makes pressure on the journals and after some time this pressure makes one or several journals explode—break the limited national scientific area and move to the international arena. As soon as one of the local journals breaks through this compressed space and appears at an international level, further explosion happens, which makes the other journals follow the same path.Design/methodology/approach: Our research is based on three international scientific databases—WoS, Scopus, and RISC CC, from where we have retrieved information about the Armenian journals indexed there and citations received by those journals and one national database—the Armenian Science Citation Index. Armenian Journal Impact Factor(ArmJIF) was calculated for the local Armenian journals based on the general impact factor formula. Journals were classified according to Gl?nzel and Schubert(2003). Findings: Our results show that the science policy developed by the scientific authorities of Armenia and the introduction of ArmJIF have made the Armenian journals comply with international standards and resulted in some local journals to break the national scientific territory and be indexed in international scientific databases of RISC, Scopus, and WoS. Apart from complying with technical requirements, the journals start publishing articles also in foreign languages. Although nearly half of the local journals are in the fields of social sciences and humanities, only one journal from that field is indexed in international scientific databases. Research limitation: One of the limitations of the study is that it was performed on the example of only one state and the second one is that more time passage is needed to firmly evaluate the results. However, the introduction of the concept can inspire other similar case study. Practical implications: The new term and relevant model offered in the article can practically be used for the development of national journals.Originality/value: The article proposes a new term and a concept in scientometrics. 展开更多
关键词 Sceintometric implosion Armenian Journal Impact Factor(ArmJIF) National scientific databases Armenian Science Citation Index(ASCI) International scientific databases
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Fast Z-Pinch,A New Approach for Promising Fusion Energy 被引量:1
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作者 Peng Xianjue,Hua Xinsheng(China Academy of Engineering Physics,Mianyang Sichuan 621900,China) 《工程科学(英文版)》 2007年第4期36-44,共9页
The basic concept of fast Z-pinch,and late progress in fast Z-pinch plasma research as HEDP and ICF research,especially as an approach for high yield low-cost fusion energy research,are summarized in this paper.The po... The basic concept of fast Z-pinch,and late progress in fast Z-pinch plasma research as HEDP and ICF research,especially as an approach for high yield low-cost fusion energy research,are summarized in this paper.The possible technical challenges of fast Z-pinch-driven ICF as fusion energy and it application prospect are discussed. 展开更多
关键词 FAST Z-PINCH IMPLOSION HEDP ICF FUSION ENERGY
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Numerical Analysis of Factors Influencing Implosion
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作者 Chen Jianguo , Dietrich R. A. and Zhu Jimao Associate Professor, Dept. of Naval Architecture and Ocean Engineering, Shanghai Jiaotong University,Shanghai 200030 Dipl. Ing., Dept. of Structural and Fluid Mechanics GKSS Research Center, 2054 Geesthacht, Germany Professor, Dept. of Naval Architecture and Ocean Engineering, Shanghai Jiaotong University, Shanghai 200030 《China Ocean Engineering》 SCIE EI 1994年第3期343-354,共12页
-By using gas-liquid two-phase flow theory, a modified mathematical model based on the computational fluid dynamics method SIMPLE (Semi-Implicit Method for Pressure-Linked Equations) is introduced to investigate implo... -By using gas-liquid two-phase flow theory, a modified mathematical model based on the computational fluid dynamics method SIMPLE (Semi-Implicit Method for Pressure-Linked Equations) is introduced to investigate implosion phenomena in high pressure chambers systematically. A theoretical simulation-prediction method, which is independent of experimental data, is developed in the paper and great improvement has been made on the topic. In the paper, various implosion situations have been simulated and predicted. Effects of a series of factors influencing implosion results and methods of reducing implosion danger have been analysed. The analysis results are of importance to underwater engineering practice. 展开更多
关键词 IMPLOSION two-phase flow implosion pressure numerical simulation/ prediction
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Diagnostic Technique of Neutron Doppler Broadening for Indirectly-Driven Implosions
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作者 熊勇 丁永坤 +1 位作者 郑志坚 陈铭 《Plasma Science and Technology》 SCIE EI CAS CSCD 2004年第3期2346-2349,共4页
The neutron Doppler broadening in inertial confinement fusion has been acquired from the time of flight for the neutron, from which the fuel ion temperature can be derived. An ultrafast-quenched plastic scintillation ... The neutron Doppler broadening in inertial confinement fusion has been acquired from the time of flight for the neutron, from which the fuel ion temperature can be derived. An ultrafast-quenched plastic scintillation detector was used to measure the time of flight for the neutron at a low-imploded DT neutron yield (5×107-1×108) in the experiment performed on the Shenguang Ⅱ laser facility. The typical temperatures of ablating targets for indirect drive were around 2.8 keV and the uncertainties were ±30 % - ±40%. The detection efficiency of the detector for DT neutrons was calibrated at a K-400 accelerator. The time response function of the detection system was calibrated by imploded neutrons from a DT-filled capsule, which can be regarded as a S function pulsed neutron source due to its much narrower pulse width than that of the measured neutron time-of-flight spectrum. 展开更多
关键词 neutron Doppler broadening indirect-driven implosions response function ion temperatures
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Rayleigh-Taylor instability of multi-fluid layers in cylindrical geometry
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作者 郭宏宇 王立锋 +2 位作者 叶文华 吴俊峰 张维岩 《Chinese Physics B》 SCIE EI CAS CSCD 2017年第12期371-376,共6页
Rayleigh-Taylor instability of three fluid layers with two interfaces in cylindrical geometry is investigated analytically. The growth rates and the amplitudes of perturbation on the two interfaces are obtained. The f... Rayleigh-Taylor instability of three fluid layers with two interfaces in cylindrical geometry is investigated analytically. The growth rates and the amplitudes of perturbation on the two interfaces are obtained. The feedback factor from outer to inner interface is larger than that from inner to outer interface under the same conditions. The growth rate on the initially unstable interface is larger than the corresponding result in planar geometry for low mode perturbation. The two interfaces are decoupled for a larger mode number perturbation. The dependencies of the amplitudes of perturbation on different initial conditions are analyzed. The negative feedback effect from initially stable interface to another unstable interface is observed. In the limit of infinity inner radius and finite shell thickness, the results in planar geometry are recovered. 展开更多
关键词 Rayleigh-Taylor instability cylindrical geometry inertial-confinement fusion implosions
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Linear Rayleigh-Taylor instability analysis of double-shell Kidder's self-similar implosion solution
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作者 胡军 尹协远 +1 位作者 杭义洪 张树道 《Applied Mathematics and Mechanics(English Edition)》 SCIE EI 2010年第4期425-438,共14页
This paper generalizes the single-shell Kidder's self-similar solution to the double-shell one with a discontinuity in density across the interface. An isentropic implosion model is constructed to study the Rayleigh-... This paper generalizes the single-shell Kidder's self-similar solution to the double-shell one with a discontinuity in density across the interface. An isentropic implosion model is constructed to study the Rayleigh-Taylor instability for the implosion compression. A Godunov-type method in the Lagrangian coordinates is used to compute the one-dimensional Euler equation with the initial and boundary conditions for the double-shell Kidder's self-similar solution in spherical geometry. Numerical results are obtained to validate the double-shell implosion model. By programming and using the linear perturbation codes, a linear stability analysis on the Rayleigh-Taylor instability for the double-shell isentropic implosion model is performed. It is found that, when the initial perturbation is concentrated much closer to the interface of the two shells, or when the spherical wave number becomes much smaller, the modal radius of the interface grows much faster, i.e., more unstable. In addition, from the spatial point of view for the compressibility effect on the perturbation evolution, the compressibility of the outer shell has a destabilization effect on the Rayleigh-Taylor instability, while the compressibility of the inner shell has a stabilization effect. 展开更多
关键词 double-shell Kidder's self-similar solution Rayleigh-Taylor instability implosion compression
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Shock Induced Symmetric Compression in a Spherical Target
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作者 Labakanta Mandal Sourav Roy +1 位作者 Manoranjan Khan R. Roychoudhury 《Journal of Modern Physics》 2015年第13期1769-1775,共7页
Shock induced symmetric compression has been studied in a spherical target. The shock induced interfacial radius will shrink and would reach a minimum point during implosion situation. However, after implosion the pla... Shock induced symmetric compression has been studied in a spherical target. The shock induced interfacial radius will shrink and would reach a minimum point during implosion situation. However, after implosion the plasma tries to expand in blow off/explosion situation and as a result the interfacial radius will increase. Effects of plasma parameters like density and temperature have been studied numerically. It is seen that the density increases many times due to the mass conservation in imploding situation of a compressible shell like ICF. However, temperature will change rapidly due to change of inner density and so would be the pressure of compressible fluid following adiabatic law. Our analytical results agree qualitatively with those of simulation results in spherical geometry and also experimental observations conducted in cylindrical container. 展开更多
关键词 Two Fluid Interface INSTABILITY Shock IMPINGEMENT ADIABATIC SYMMETRIC Compression IMPLOSION
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Chimney ImplosionmA Case Study
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作者 Ajay Kumar Jha 《Journal of Geological Resource and Engineering》 2014年第1期32-38,共7页
Chimney implosion is the strategic planning of explosives and accessories materials and timings of its detonation so that chimney collapses on itself, minimising the physical damage to its immediate surroundings. Buil... Chimney implosion is the strategic planning of explosives and accessories materials and timings of its detonation so that chimney collapses on itself, minimising the physical damage to its immediate surroundings. Built in 1885, the brick chimney at kankanee colliery, Sijua area, BCCL (Bharat Collieries Company Limited) was demolished by felling method using the commercial explosives by adopting single-folding and toppling method. The chimney was 31.5 m in height and suffered structural weaknesses due to progressive deterioration over age, weathering and non maintenance. The chimney was posing potential threat to the safety of the nearby dwellings and surface structures, viz. main mechanical ventilator of Kankanee colliery, 11 KV electrical substation supplying power to Sijua area, BCCL, high tension cable line and busy Katras-Sijua-Dhanbad Dobari Road all failing within a radius of 30 m. About 75.22 kg of commercial explosive, 100 m of detonating fuse along with 0 and 25 ms delay detonators were used for controlled demolition of chimney. The chimney got demolished by vertically cascading on its own base without causing any damage to the nearby dwellings and surface structures. 展开更多
关键词 IMPLOSION chimney demolition.
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