Hydrodynamic Instabilities in Inertial Fusion

Hydrodynamic Instabilities in Inertial Fusion PDF Author:
Publisher:
ISBN:
Category :
Languages : en
Pages : 20

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Book Description
This report discusses topics on hydrodynamics instabilities in inertial confinement: linear analysis of Rayleigh-Taylor instability; ablation-surface instability; bubble rise in late-stage Rayleigh-Taylor instability; and saturation and multimode interactions in intermediate-stage Rayleigh-Taylor instability.

Hydrodynamic Instabilities in Inertial Fusion

Hydrodynamic Instabilities in Inertial Fusion PDF Author:
Publisher:
ISBN:
Category :
Languages : en
Pages : 20

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Book Description
This report discusses topics on hydrodynamics instabilities in inertial confinement: linear analysis of Rayleigh-Taylor instability; ablation-surface instability; bubble rise in late-stage Rayleigh-Taylor instability; and saturation and multimode interactions in intermediate-stage Rayleigh-Taylor instability.

サムソンとデリラ

サムソンとデリラ PDF Author:
Publisher:
ISBN:
Category :
Languages : en
Pages : 84

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Book Description


Hydrodynamic Instabilities in Inertial Confinement Fusion

Hydrodynamic Instabilities in Inertial Confinement Fusion PDF Author: Samuel Carl Miller
Publisher:
ISBN:
Category :
Languages : en
Pages : 169

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Book Description
"Performance degradation in laser direct-drive (LDD) inertial confinement fusion (ICF) implosions is caused by several effects, including Rayleigh-Taylor (RT) and Richtmyer-Meshkov (RM) hydrodynamic instability growth. RT instability growth occurs in both the acceleration and deceleration phases of implosions. The first half of this thesis examines the evolution of internal perturbations that create seeds for instability growth during shock-transit (or early-time), while the second half describes the perturbation evolution during shell deceleration. During shock-transit, perturbations from shell material density modulations and isolated defects plant seeds at various interfaces such as the ablation front and material interfaces. These seeds can become amplified due to secular feedout growth and shock-induced vorticity and will grow exponentially during the acceleration phase due to ablative RT. A comprehensive understanding of this evolution is essential to characterize the impact of internal defects on inflight shell integrity. Through detailed simulations and analysis, this thesis identifies several key physical processes that play a role in the evolution of perturbations created by these defects throughout the early stage of implosions. Simulations also predict that significant shell mass modulations develop during shell acceleration. The use of low density ablator materials (foam) is suggested as a potential mitigation strategy to reduce the effects created by these defects. To perform this detailed study of internal defect evolution, two new high-fidelity physics codes were developed to track characteristic wave propagation in the ICF context using low-noise, low-dissipation, high-order spatial accuracy solution methods. Modern high performance computing (HPC) systems have becoming increasingly complex, and adapting existing or new software to fully utilize them is a significant development challenge. Each code in this thesis examines the feasibility of different approaches: a modern design in a well-known HPC-centric language (Fortran), and a new language (Julia), which emphasizes developer productivity and shows the potential to be well-suited for HPC workloads. Mass modulations at the ablation front, which grow during the acceleration phase, feed through to the inner surface of the shell and create seeds for deceleration phase RT growth at the inner surface. Deceleration instability growth was studied using laser direct drive implosions of room-temperature plastic targets. Perturbation growth in such implosions is enhanced by the density discontinuity and finite Atwood number at the fuel-shell interface. The magnitude of this density discontinuity can be controlled by changing the fuel composition (D:T, or ratio of deuterium to tritium). However, this thesis demonstrates that the stability of the interface is best characterized by the effective Atwood number, which is primarily determined by material densities at distances on the order of perturbation wavelength on either side of the interface, rather than the density ratio at the interface. Since the densities at these distances are defined not by fuel composition, but radiation heating of the shell, both simulation and experimental data show that target performance is insensitive to different D:T ratios"--Pages ix -x

The Physics of Inertial Fusion

The Physics of Inertial Fusion PDF Author: Stefano Atzeni
Publisher: OUP Oxford
ISBN: 0191524050
Category : Science
Languages : en
Pages : 481

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Book Description
This book is on inertial confinement fusion, an alternative way to produce electrical power from hydrogen fuel by using powerful lasers or particle beams. It involves the compression of tiny amounts (micrograms) of fuel to thousand times solid density and pressures otherwise existing only in the centre of stars. Thanks to advances in laser technology, it is now possible to produce such extreme states of matter in the laboratory. Recent developments have boosted laser intensities again with new possibilities for laser particle accelerators, laser nuclear physics, and fast ignition of fusion targets. This is a reference book for those working on beam plasma physics, be it in the context of fundamental research or applications to fusion energy or novel ultra-bright laser sources. The book combines quite different areas of physics: beam target interaction, dense plasmas, hydrodynamic implosion and instabilities, radiative energy transfer as well as fusion reactions. Particular attention is given to simple and useful modelling, including dimensional analysis and similarity solutions. Both authors have worked in this field for more than 20 years. They want to address in particular those teaching this topic to students and all those interested in understanding the technical basis.

Fundamental Studies of Shock-Driven Hydrodynamic Instabilities

Fundamental Studies of Shock-Driven Hydrodynamic Instabilities PDF Author: Yu Liang
Publisher: Springer Nature
ISBN: 9811929920
Category : Technology & Engineering
Languages : en
Pages : 201

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Book Description
This book illustrates the latest progress on the hydrodynamic instabilities induced by a shock wave, particularly RM (Richtmyer–Meshkov) instability. The hydrodynamic instabilities play crucial roles in various industrial and scientific fields, such as inertial confinement fusion, supersonic combustion, supernova explosion, etc. This book experimentally and theoretically explores the shock-driven instabilities of complex gas-gas and gas-liquid interfaces. The main difficulty in performing an experimental study on RM instability, especially in a shock-tube circumstance, lies in creating an idealized initial interface because the RM instability is extremely sensitive to the initial condition. This book introduces new experimental methods to generate shape-controllable two-dimensional gaseous interfaces, thickness-controllable gas layers, and water droplets embedded with a vapour bubble in the shock-tube experiments. It covers the latest experiments and theories on the shock-driven hydrodynamic instabilities of multi-mode, multi-layer, and multi-phase interfaces. It explores the effects of the mode-competition, interface-coupling, and phase-transition on interface evolution, respectively. This book establishes a universal nonlinear theory to predict the RM instability of a shocked multi-mode interface based on spectrum analysis. This book quantifies the effects of interface-coupling and reverberating waves on the hydrodynamic instabilities of a shocked multi-layer interface. This book provides the experimental studies of the interaction of a shock wave and a multi-phase droplet and proposes a modified Rayleigh-Plesset equation to predict the vapour bubble collapse inside a droplet.

The Influence of Three Dimensional Effects of the Core Dynamics and Nuclear Measurements of Inertial Fusion Implosions

The Influence of Three Dimensional Effects of the Core Dynamics and Nuclear Measurements of Inertial Fusion Implosions PDF Author: Ka Ming Woo
Publisher:
ISBN:
Category :
Languages : en
Pages : 244

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Book Description
"Hydrodynamic instability is one of the primary sources of degrading the fusion yields in inertial confinement fusion (ICF) experiments. The presence of non-uniformities during the hot spot formation leads to dominant experimental signatures of implosion asymmetries. The physical mechanism of how hydrodynamic instabilities manifest themselves in experimental observable plays an important role to interpret three-dimensional (3-D) effects on ICF experimental data. In the first part of the thesis, we describe the development of a 3-D radiation hydrodynamic Eulerian spherical moving-mesh parallel code DEC3D to model the deceleration-phase Rayleigh-Taylor instability. The new code implements advanced modern numerical methods including the high-resolution shock-capturing technique the piecewise parabolic method for hydrodynamics, the macro-zoning technique to treat small time-step problems of the spherical mesh, and the integration of HYPRE to solve the implicit multi-group radiation diffusion. A single mode and multi-mode simulation database was established to study the relations between 3-D hydrodynamic effects and implosion asymmetries. In the second part of the thesis, two comprehensive physical models were developed: (1) to explain the effects of the residual kinetic energy on the degradation of fusion yields and hot-spot pressures, and the property of larger hot-spot volumes for low modes, and (2) to explain the effects of 3-D hot-spot ow asymmetries on the variations of ion-temperature measurements. An analytical method of velocity variance decomposition was developed to infer the minimum ion temperatures and explain the physical mechanism of larger apparent ion temperatures than the true thermal ion temperatures."--Pages xiii-xiv.

Nuclear Fusion by Inertial Confinement

Nuclear Fusion by Inertial Confinement PDF Author: Guillermo Velarde
Publisher: CRC Press
ISBN: 9780849369261
Category : Science
Languages : en
Pages : 784

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Book Description
Nuclear Fusion by Inertial Confinement provides a comprehensive analysis of directly driven inertial confinement fusion. All important aspects of the process are covered, including scientific considerations that support the concept, lasers and particle beams as drivers, target fabrication, analytical and numerical calculations, and materials and engineering considerations. Authors from Australia, Germany, Italy, Japan, Russia, Spain, and the U.S. have contributed to the volume, making it an internationally significant work for all scientists working in the Inertial Confinement Fusion (ICF) field, as well as for graduate students in engineering and physics with interest in ICF.

Hydrodynamic Instabilities and Turbulence

Hydrodynamic Instabilities and Turbulence PDF Author: Ye Zhou
Publisher: Cambridge University Press
ISBN: 1108489648
Category : Mathematics
Languages : en
Pages : 611

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Book Description
The first comprehensive reference guide to turbulent mixing driven by Rayleigh-Taylor, Richtmyer-Meshkov and Kelvin-Helmholtz instabilities.

An Introduction to Inertial Confinement Fusion

An Introduction to Inertial Confinement Fusion PDF Author: Susanne Pfalzner
Publisher: CRC Press
ISBN: 1420011847
Category : Science
Languages : en
Pages : 244

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Book Description
Newcomers to the field of inertial confinement fusion (ICF) often have difficulty establishing a clear picture of the overall field. The reason for this is because, while there are many books devoted to special topics within the field, there is none that provides an overview of the field as a whole. An Introduction to Inertial Confinement Fusion fi

The Physics of Inertial Fusion

The Physics of Inertial Fusion PDF Author: Stefano Atzeni
Publisher: OUP Oxford
ISBN: 9780191524059
Category : Science
Languages : en
Pages : 488

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Book Description
This book is on inertial confinement fusion, an alternative way to produce electrical power from hydrogen fuel by using powerful lasers or particle beams. It involves the compression of tiny amounts (micrograms) of fuel to thousand times solid density and pressures otherwise existing only in the centre of stars. Thanks to advances in laser technology, it is now possible to produce such extreme states of matter in the laboratory. Recent developments have boosted laser intensities again with new possibilities for laser particle accelerators, laser nuclear physics, and fast ignition of fusion targets. This is a reference book for those working on beam plasma physics, be it in the context of fundamental research or applications to fusion energy or novel ultra-bright laser sources. The book combines quite different areas of physics: beam target interaction, dense plasmas, hydrodynamic implosion and instabilities, radiative energy transfer as well as fusion reactions. Particular attention is given to simple and useful modelling, including dimensional analysis and similarity solutions. Both authors have worked in this field for more than 20 years. They want to address in particular those teaching this topic to students and all those interested in understanding the technical basis.