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Author: Robert Adam Barchfeld
Publisher:
ISBN: 9780355149210
Category :
Languages : en
Pages :
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Book Description
Worldwide demand for power, and in particular electricity, is growing. Increasing population, expanding dependence on electrical devices, as well as the development of emerging nations, has created significant challenges for the power production. Compounding the issue are concerns over pollution, natural resource supplies, and political obstacles in troubled parts of the world. Many believe that investment in renewable energy will solve the expected energy crisis; however, renewable energy has many shortfalls. Consequently, additional sources of energy should be explored to provide the best options for the future. Electricity from fusion power offers many advantages over competing technologies. It can potentially produce large amounts of clean energy, without the serious concerns of fission power plant safety and nuclear waste. Fuel supplies for fusion are plentiful. Fusion power plants can be operated as needed, without dependence on location, or local conditions. However, there are significant challenges before fusion can be realized. Many factors currently limit the effectiveness of fusion power, which prevents a commercial power plant from being feasible. Scientists in many countries have built, and operate, experimental fusion plants to study the fusion process. The leading examples are magnetic confinement reactors known as tokamaks. At present, reactor gain is near unity, where the fusion power output is nearly the same as the power required to operate the reactor. A tenfold increase in gain is what reactors such as ITER hope to achieve, where ~50 MW will be used for plasma heating, magnetic fields, and so forth, with a power output of ~500 MW. Before this can happen, further research is required. Loss of particle and energy confinement is a principal cause of low performance; therefore, increasing confinement time is key. There are many causes of thermal and particle transport that are being researched, and the prime tools for conducting this research are plasma diagnostics. Plasma diagnostics collect data from fusion reactors in a number of different ways. Among these are far infrared (FIR) laser based systems. By probing a fusion plasma with FIR lasers, many properties can be measured, such as density and density fluctuations. This dissertation discusses the theory and design of two laser based diagnostic instruments: 1) the Far Infrared Tangential Interferometer and Polarimeter (FIReTIP) systems, and 2) the High-k[subscript theta] Scattering System. Both of these systems have been designed and fabricated at UC Davis for use on the National Spherical Torus Experiment - Upgrade (NSTX-U), located at Princeton Plasma Physics Laboratory (PPPL). These systems will aid PPPL scientists in fusion research. The FIReTIP system uses 119 [mu]m methanol lasers to pass through the plasma core to measure a chord averaged plasma density through interferometry. It can also measure the toroidal magnetic field strength by the way of polarimetery. The High-k[subscript theta] Scattering System uses a 693 GHz formic acid laser to measure electron scale turbulence. Through collective Thomson scattering, as the probe beam passes through the plasma, collective electron motion will scatter power to a receiver with the angle determined by the turbulence wavenumber. This diagnostic will measure k[subscript theta] from 7 to 40 cm-1 with a 4-channel receiver array. The High-k[subscript theta] Scattering system was designed to facilitate research on electron temperature gradient (ETG) modes, which are believed to be a major contributor to anomalous transport on NSTX-U. The design and testing of these plasma diagnostics are described in detail. There are a broad range of components detailed including: optically pumped gas FIR lasers, overmoded low loss waveguide, launching and receiving optical designs, quasi-optical mixers, electronics, and monitoring and control systems. Additionally, details are provided for laser maintenance, alignment techniques, and the fundamentals of nano-CNC-machining.
Author: Robert Adam Barchfeld
Publisher:
ISBN: 9780355149210
Category :
Languages : en
Pages :
Get Book Here
Book Description
Worldwide demand for power, and in particular electricity, is growing. Increasing population, expanding dependence on electrical devices, as well as the development of emerging nations, has created significant challenges for the power production. Compounding the issue are concerns over pollution, natural resource supplies, and political obstacles in troubled parts of the world. Many believe that investment in renewable energy will solve the expected energy crisis; however, renewable energy has many shortfalls. Consequently, additional sources of energy should be explored to provide the best options for the future. Electricity from fusion power offers many advantages over competing technologies. It can potentially produce large amounts of clean energy, without the serious concerns of fission power plant safety and nuclear waste. Fuel supplies for fusion are plentiful. Fusion power plants can be operated as needed, without dependence on location, or local conditions. However, there are significant challenges before fusion can be realized. Many factors currently limit the effectiveness of fusion power, which prevents a commercial power plant from being feasible. Scientists in many countries have built, and operate, experimental fusion plants to study the fusion process. The leading examples are magnetic confinement reactors known as tokamaks. At present, reactor gain is near unity, where the fusion power output is nearly the same as the power required to operate the reactor. A tenfold increase in gain is what reactors such as ITER hope to achieve, where ~50 MW will be used for plasma heating, magnetic fields, and so forth, with a power output of ~500 MW. Before this can happen, further research is required. Loss of particle and energy confinement is a principal cause of low performance; therefore, increasing confinement time is key. There are many causes of thermal and particle transport that are being researched, and the prime tools for conducting this research are plasma diagnostics. Plasma diagnostics collect data from fusion reactors in a number of different ways. Among these are far infrared (FIR) laser based systems. By probing a fusion plasma with FIR lasers, many properties can be measured, such as density and density fluctuations. This dissertation discusses the theory and design of two laser based diagnostic instruments: 1) the Far Infrared Tangential Interferometer and Polarimeter (FIReTIP) systems, and 2) the High-k[subscript theta] Scattering System. Both of these systems have been designed and fabricated at UC Davis for use on the National Spherical Torus Experiment - Upgrade (NSTX-U), located at Princeton Plasma Physics Laboratory (PPPL). These systems will aid PPPL scientists in fusion research. The FIReTIP system uses 119 [mu]m methanol lasers to pass through the plasma core to measure a chord averaged plasma density through interferometry. It can also measure the toroidal magnetic field strength by the way of polarimetery. The High-k[subscript theta] Scattering System uses a 693 GHz formic acid laser to measure electron scale turbulence. Through collective Thomson scattering, as the probe beam passes through the plasma, collective electron motion will scatter power to a receiver with the angle determined by the turbulence wavenumber. This diagnostic will measure k[subscript theta] from 7 to 40 cm-1 with a 4-channel receiver array. The High-k[subscript theta] Scattering system was designed to facilitate research on electron temperature gradient (ETG) modes, which are believed to be a major contributor to anomalous transport on NSTX-U. The design and testing of these plasma diagnostics are described in detail. There are a broad range of components detailed including: optically pumped gas FIR lasers, overmoded low loss waveguide, launching and receiving optical designs, quasi-optical mixers, electronics, and monitoring and control systems. Additionally, details are provided for laser maintenance, alignment techniques, and the fundamentals of nano-CNC-machining.
Author: Thomas Martin Lehecka
Publisher:
ISBN:
Category :
Languages : en
Pages : 202
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Book Description
Author: I. Podgornyi
Publisher: Springer
ISBN:
Category : Science
Languages : en
Pages : 240
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Book Description
The present volume is essentially a qualitative survey of modern trends in the diagnostics of high-temperature plasmas, with particular orientation toward laboratory plasmas of interest in connection with research in controlled thermonuclear fusion. Among the broad topics considered are probe diagnostics, optical methods (including the use of lasers and holography), microwave diagnostics, and diagnostics with particle beams. Having infor mation on these methods available in compact form and in one place, as is the case in the present volume, should make it pos sible to evaluate different diagnostic approaches to specific prob lems. The volume will be useful as an introduction for advanced students making their first contact with experimental plasma physics and for physicists and engineers who are entering the field and desire a rapid survey of principles and modern trends in the diagnostics of high-temperature plasmas. v Foreword to the American Edition The material in this book is based on lectures given at Mos cow State University. It is intended to acquaint the reader with the basic aspects of plasma diagnostics and contains information re quired for the experimental physicist who wishes to carry out straightforward measurements of laboratory plasmas. It will be evident that in choosing the material we have been guided pri marily by the scientific interests of the author, and the great bulk of the material is based on work carried out in the USSR.
Author:
Publisher:
ISBN:
Category :
Languages : en
Pages :
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Book Description
Laser induced fusion is the forerunner of a class of inertial confinement schemes in which hydrogen isotopes are heated to thermonuclear conditions in a very short period. The process is characterized by such short time scales that fuel confinement is achieved through its' own finite mass and expansion velocity, approaching 1 .mu.m/psec for ignition temperatures of order 10 keV (108 °K). With current laser powers limited to several terrawatts one readily estimates, on the basis of energy conservation, target mass, and expansion velocity, that target size and laser pulse duration are on the order of 100 .mu.m and 100 psec, respectively. Within these constraints, targets have been heated and confined to the point where thermonuclear conditions have been achieved. This paper describes a sampling of diagnostic techniques with requisite resolution (microns and picoseconds) to accurately describe the dynamics of a laser driven compression. As discussed in each case cited, these in turn provide insight to and quantitative measure of, the physical processes dominating the implosion. The success of the inertial confinement fusion program is strongly dependent on the continued development of such diagnostics and the understanding they provide.
Author:
Publisher:
ISBN:
Category :
Languages : en
Pages : 23
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Book Description
Ultrashort laser pulse systems allow examination of intense, ultrafast laser-plasma interactions. More specifically, intense laser irradiation can induce short xuv/x-ray bursts from the surface of condensed phase targets. Ultrafast xuv/x-ray detection is needed to understand laser-plasma interactions in this dynamic regime. Support of the Stockpile Stewardship and Management Program requires this critical understanding. Our effort here has been to extend understanding of atomic-scale dynamics in such environments with the goal of developing next generation ultrafast xuv/x-ray diagnostics where the sensors will be the atoms and ions themselves and the time resolution will approach that of the induced atomic transitions ((almost equal to) a few femtoseconds). Pivotal contributions to the rapidly developing field of highly nonperturbative interactions of ultrashort pulse lasers with atoms/ions have been made at this laboratory. In the visible/infrared wavelength regions the temporal and spectral content of ultrashort laser pulses are now reliably monitored within a single pulse using frequency resolved optical gating (FROG) which is based on rapid nonlinear optical processes such as the Kerr effect. New applications of this basic concept are still being developed. Corresponding detection for the xuv/x-ray wavelengths does not exist and is urgently needed in many laboratory programs. The FROG technique cannot be applied in the xuv/x-ray region. Current x-ray streak camera technology is limited to (almost equal to)0.5 picosecond resolution.
Author: B. H. Ripin
Publisher:
ISBN:
Category :
Languages : en
Pages : 31
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Book Description
Laser plasma interaction experiments have now advanced to the point where very quantitative measurements are required to elucidate the physic issues important for laser fusion and other applications. Detailed time-resolved knowledge of the plasma density, temperature, velocity gradients, spatial structure, heat flow characteristics, radiation emission, etc, are needed over tremendou ranges of plasma density and temperature. Moreover, the time scales are very short, aggrevating the difficulty of the measurements further. Nonetheless, such substantial progress has been made in diagnostic development during the past few years that we are now able to do well diagnosed experiments. In this paper the authors review recent diagnostic developments for laser-plasma interactions, outline their regimes of applicability, and show examples of their utility. In addition to diagnostics for the high densities and temperature characteristic of laser fusion physics studies, diagnostics designed to study the two-stream interactions of laser created plasma flowing through an ambient low density plasma will be described.
Author: D. W. Scudder
Publisher:
ISBN:
Category :
Languages : en
Pages : 169
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Book Description
The research performed under this program has covered a broad range of subjects involving laser interaction with both gaseous and solid target laser plasmas, and with development of plasma diagnostic techniques suitable for our laser-produced plasmas. Included are detailed descriptions of research activities during fiscal years 1978 and 1979. These include a study of stimulated Brillouin scattering in transverse magnetic fields; development of X-ray diagnostics including X-ray continuum measurements, spectroscopy, and imaging techniques and their use in studying solid target plasmas; development of a fast schlieren photography system; and a theoretical study of nonlinear scattering techniques for plasma diagnostics.
Author: Zhitong Chen
Publisher: Mdpi AG
ISBN: 9783036543192
Category : Technology & Engineering
Languages : en
Pages : 0
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Book Description
Plasma can be generated via the combination of energy-inducing fragmentation, ionization, and excitation of molecular. Such processes occur throughout the life of the plasma, resulting in a wide variety of atomic and molecular species, which can be electrically charged, energetically excited, highly reactive, or any combination of these states. Plasma diagnostics can demonstrate important discharge characteristics and the mechanisms of plasma-induced processes. Parameter's dynamic range spans many orders of magnitude, and spatial/temporal scales significantly vary during plasma source configurations. Many diagnostic techniques have been developed to characterize plasma, including scattering techniques, intensified charge-coupled device cameras, laser-based methods, optical emission spectroscopy, mass spectrometry, electron paramagnetic resonance spectroscopy, gas chromatography, etc. Although various mature diagnostic technologies for plasma discharges have been developed, there are still many challenges. The measurement precision is not only affected by the diagnostic equipment/ techniques, but also by the plasma discharge itself. In many applications, direct measurements of the parameters of interest are still not possible. In addition, the plasma environments in application processes are unusually complex, and their reactions are still not fully understood. Plasma can exist in a variety of forms due to discharge modes resulting from different means of creation, resulting in a wide range of applications. This brings together many research fields, including physics, engineering, chemistry, biology, and medicine.
Author: Ronald C Davidson
Publisher: World Scientific
ISBN: 1911298186
Category : Science
Languages : en
Pages : 603
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Book Description
Physics of Intense Charged Particle Beams in High Energy Accelerators is a graduate-level text — complete with 75 assigned problems — which covers a broad range of topics related to the fundamental properties of collective processes and nonlinear dynamics of intense charged particle beams in periodic focusing accelerators and transport systems. The subject matter is treated systematically from first principles, using a unified theoretical approach, and the emphasis is on the development of basic concepts that illustrate the underlying physical processes in circumstances where intense self fields play a major role in determining the evolution of the system. The theoretical analysis includes the full influence of dc space charge and intense self-field effects on detailed equilibrium, stability and transport properties, and is valid over a wide range of system parameters ranging from moderate-intensity, moderate-emittance beams to very-high-intensity, low-emittance beams. This is particularly important at the high beam intensities envisioned for present and next generation accelerators, colliders and transport systems for high energy and nuclear physics applications and for heavy ion fusion. The statistical models used to describe the properties of intense charged particle beams are based on the Vlasov-Maxwell equations, the macroscopic fluid-Maxwell equations, or the Klimontovich-Maxwell equations, as appropriate, and extensive use is made of theoretical techniques developed in the description of one-component nonneutral plasmas, and multispecies electrically-neutral plasmas, as well as established techniques in accelerator physics, classical mechanics, electrodynamics and statistical physics.Physics of Intense Charged Particle Beams in High Energy Accelerators emphasizes basic physics principles, and the thorough presentation style is intended to have a lasting appeal to graduate students and researchers alike. Because of the advanced theoretical techniques developed for describing one-component charged particle systems, a useful companion volume to this book is Physics of Nonneutral Plasmas by Ronald C Davidson./a
Author: A. Tserepi
Publisher:
ISBN:
Category : Lasers
Languages : en
Pages :
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Book Description
The two-photon laser induced fluorescence (TALIF) diagnostic has been developed and/or applied to plasma processing systems involving H, 0, and N atoms. Based upon TALIF data, models have been developed for the spatial and temporal variation of the absolute atomic concentrations in H2, 02, and N2 plasmas. The portability of the TALIF diagnostic has been demonstrated. Limitations of the technique due to stimulated emission and fluorescence quenching have been investigated and procedures developed to minimize their effects.
