Download or read book The Importance of the Radial Electric Field E sub R on Interpretation of Motional Stark Effect Measurements of the Q Profile in DIII D High Performance Plasmas written by and published by . This book was released on 1997 with total page 7 pages. Available in PDF, EPUB and Kindle. Book excerpt: The development of enhanced confinement regimes such as negative central magnetic shear (NCS) and VH-mode illustrates the importance of the q profile and ExB velocity shear in improving stability and confinement in tokamak plasmas. Recently, it was realized that the large values of radial electric field observed in these high performance plasmas, up to 200 kV/m in DIII-D, have an effect on the interpretation of motional Stark effect (MSE) measurements of the q profile. It has also been shown that, with additional MSE measurements, one can extract a direct measurement of E{sub r} in addition to the usual poloidal field measurement. During a recent vent on DIII-D, 19 additional MSE channels with new viewing angles were added (for a total of 35 channels) in order to descriminate between the neutral beam v{sub b} x B electric field and the plasma E{sub r} field. In this paper, the system upgrade will be described and initial measurements demonstrating simultaneous measurement of the q and E{sub r} profiles will be presented.
Download or read book Nuclear Fusion written by and published by . This book was released on 2003 with total page 574 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Physics Briefs written by and published by . This book was released on 1994 with total page 1248 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Overview of Equilibrium Reconstruction on DIII D Using New Measurements from an Expanded Motional Stark Effect Diagnostic written by and published by . This book was released on 2008 with total page 16 pages. Available in PDF, EPUB and Kindle. Book excerpt: Motional Stark effect (MSE) measurements constrain equilibrium reconstruction of DIII-D tokamak plasmas using the equilibrium code EFIT. In 2007, two new MSE arrays were brought online, bringing the system to three core arrays, two edge arrays, and 64 total channels. We present the first EFIT reconstructions using this expanded system. Safety factor and E{sub R} profiles produced by fitting to data from the two new arrays and one of the other three agree well with independent measurements. Comparison of the data from the three arrays that view the core shows that one of the older arrays is inconsistent with the other two unless the measured calibration factors for this array are adjusted. The required adjustments depend on toroidal field and plasma current direction, and on still other uncertain factors that change as the plasma evolves. We discuss possible sources of calibration error for this array.
Download or read book An Overview Of The Motional Stark Effect Diagnostic On DIII D And Design Work For An ITER MSE written by and published by . This book was released on 2007 with total page 6 pages. Available in PDF, EPUB and Kindle. Book excerpt: The advanced tokamak research program at DIII-D relies critically on the measurement of the current density profile. This was made possible by the development of a Motional Stark Effect (MSE) polarimeter that was first installed in 1992. Three major upgrades have since occurred, and improvements in our understanding of critical performance issues and calibration techniques are ongoing. In parallel with these improvements, we have drawn on our DIII-D experience to begin studies and design work for MSE on burning plasmas and ITER. This paper first reviews how Motional Stark Effect polarimetry (MSE) is used to determine the tokamak current profile. It uses the DIII-D MSE system as an example, and shows results from the latest upgrade that incorporates an array of channels from a new counter-Ip injected neutral beam. The various calibration techniques presently used are reviewed. High-leverage or unresolved issues affecting MSE performance and reliability in ITER are discussed. Next, we show a four-mirror collection optics design for the two ITER MSE views. Finally, we discuss measurements of the polarization properties of a few candidate mirrors for the ITER MSE.
Download or read book Motional Stark Effect Upgrades on DIII D written by and published by . This book was released on 1994 with total page 9 pages. Available in PDF, EPUB and Kindle. Book excerpt: The measurement and control of the plasma current density profile (or q profile) is critical to the advanced tokamak program on DIII-D.A complete understanding of the stability and transport properties of advanced operating regimes requires detail poloidal field measurements over the entire plasma radius from the core to the edge. In support of this effort, the authors have recently completed an upgrade of the existing MSE diagnostic, increasing the number of channels from 8 to 16. A new viewing geometry has been added to the outer edge of the plasma which improves the radial resolution in this region from 10 cm to
Download or read book Radiative Processes in Astrophysics written by George B. Rybicki and published by John Wiley & Sons. This book was released on 2008-09-26 with total page 400 pages. Available in PDF, EPUB and Kindle. Book excerpt: Radiative Processes in Astrophysics: This clear, straightforward, and fundamental introduction is designed to present-from a physicist's point of view-radiation processes and their applications to astrophysical phenomena and space science. It covers such topics as radiative transfer theory, relativistic covariance and kinematics, bremsstrahlung radiation, synchrotron radiation, Compton scattering, some plasma effects, and radiative transitions in atoms. Discussion begins with first principles, physically motivating and deriving all results rather than merely presenting finished formulae. However, a reasonably good physics background (introductory quantum mechanics, intermediate electromagnetic theory, special relativity, and some statistical mechanics) is required. Much of this prerequisite material is provided by brief reviews, making the book a self-contained reference for workers in the field as well as the ideal text for senior or first-year graduate students of astronomy, astrophysics, and related physics courses. Radiative Processes in Astrophysics also contains about 75 problems, with solutions, illustrating applications of the material and methods for calculating results. This important and integral section emphasizes physical intuition by presenting important results that are used throughout the main text; it is here that most of the practical astrophysical applications become apparent.
Download or read book Motional Stark Effect Polarimetry for the Current Profile Diagnostic in DIII D written by and published by . This book was released on 1990 with total page 15 pages. Available in PDF, EPUB and Kindle. Book excerpt: Motional Stark effect produces large net linear polarization of hydrogenic beam emissions. Measurement of the polarization direction permits to determine the local magnetic field pitch angle. Design of a single point, spatially scannable, high-sensitivity polarimeter installed on DIII-D is described. Excellent signal-to-noise ratio with good temporal and spatial resolution was obtained in preliminary measurements of magnetic field pitch angle. 9 refs., 3 figs.
Download or read book Principles of Plasma Diagnostics written by I. H. Hutchinson and published by Cambridge University Press. This book was released on 2005-07-14 with total page 460 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book provides a systematic introduction to the physics of plasma diagnostics measurements. It develops from first principles the concepts needed to plan, execute and interpret plasma measurements, making it a suitable book for graduate students and professionals with little plasma physics background. The book will also be a valuable reference for seasoned plasma physicists, both experimental and theoretical, as well as those with an interest in space and astrophysical applications. This second edition is thoroughly revised and updated, with new sections and chapters covering recent developments in the field.
Download or read book H mode and VH mode Confinement Improvement in DIII D Investigations of Turbulence Local Transport and Active Control of the Shear in the E times B Flow written by and published by . This book was released on 2001 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: The hypothesis of stabilization of turbulence by shear in the E[times] B drift speed successfully predicts the observed turbulence reduction and confinement improvement seen at the L to H transition. This same hypothesis is the best explanation to date for the further confinement improvement seen in the plasma core when the plasma goes from H-mode to VH-mode. Consequently, the most fundamental question for H-mode studies now is: how is the electric field E[sub r] formed? The radial force balance equation relates E[sub r] to the main ion pressure gradient[triangledown]P[sub i], poloidal rotation[nu][sub[theta]i], and toroidal rotation[nu][sub[phi]i]. In the plasma edge, direct measurements show[triangledown]P[sub i] and[nu][sub[theta]i] are the important terms at the L to H transition, with[triangledown]P[sub i] being the dominant, negative term throughout most of the H-mode. Since E[sub r] is observed to change prior to the change in[triangledown]P[sub i], the authors infer that main ion rotation, probably[nu][sub[theta]i], changes first, triggering the transition. E[sub r] is seen to change prior to the change in fluctuations, consistent with E[times] B shear causing the change in fluctuations and transport. In the plasma core, E[sub r] is primarily related to[nu][sub[phi]i]. There is a clear temporal and spatial correlation between the change in E[times] B shear and the region of local confinement improvement when the plasma goes from H-mode to VH-mode. Direct manipulation of[nu][sub[phi]i] and E[times] B shear using the drag produced by a non-axisymmetric magnetic perturbation has produced clear changes in local transport consistent with the E[times] B shear stabilization hypothesis. The implications of these results for theories of the L to H and H to VH transitions will be discussed. 83 refs., 5 figs.
Download or read book Handbook of X Ray Data written by Günter H. Zschornack and published by Springer Science & Business Media. This book was released on 2007-01-24 with total page 969 pages. Available in PDF, EPUB and Kindle. Book excerpt: This is the only handbook available on X-ray data. In a concise and informative manner, the most important data connected with the emission of characteristic X-ray lines are tabulated for all elements up to Z = 95 (Americium). The tabulated data are characterized and, in most cases, evaluated. Furthermore, all important processes and phenomena connected with the production, emission and detection of characteristic X-rays are discussed.
Download or read book Fusion Plasma Diagnostics with mm Waves written by Hans-Jürgen Hartfuß and published by John Wiley & Sons. This book was released on 2013-08-22 with total page 429 pages. Available in PDF, EPUB and Kindle. Book excerpt: Filling a gap in the literature, this introduction to the topic covers the physics of the standard microwave diagnostics established on modern fusion experiments, and the necessary technological background from the field of microwave engineering. Written by well-known mm-wave diagnosticians in the field of fusion physics, the textbook includes such major diagnostic techniques as electron cyclotron emission, interferometry, reflectometry, polarimetry, and scattering.
Download or read book Optical Properties of Solids written by Frederick Wooten and published by Academic Press. This book was released on 2013-10-22 with total page 273 pages. Available in PDF, EPUB and Kindle. Book excerpt: Optical Properties of Solids covers the important concepts of intrinsic optical properties and photoelectric emission. The book starts by providing an introduction to the fundamental optical spectra of solids. The text then discusses Maxwell's equations and the dielectric function; absorption and dispersion; and the theory of free-electron metals. The quantum mechanical theory of direct and indirect transitions between bands; the applications of dispersion relations; and the derivation of an expression for the dielectric function in the self-consistent field approximation are also encompassed. The book further tackles current-current correlations; the fluctuation-dissipation theorem; and the effect of surface plasmons on optical properties and photoemission. People involved in the study of the optical properties of solids will find the book invaluable.
Download or read book Ultrashort Laser Pulse Phenomena written by Jean-Claude Diels and published by Elsevier. This book was released on 2006-09-21 with total page 675 pages. Available in PDF, EPUB and Kindle. Book excerpt: Ultrashort Laser Pulse Phenomena, Second Edition serves as an introduction to the phenomena of ultra short laser pulses and describes how this technology can be used to examine problems in areas such as electromagnetism, optics, and quantum mechanics. Ultrashort Laser Pulse Phenomena combines theoretical backgrounds and experimental techniques and will serve as a manual on designing and constructing femtosecond ("faster than electronics") systems or experiments from scratch. Beyond the simple optical system, the various sources of ultrashort pulses are presented, again with emphasis on the basic concepts and how they apply to the design of particular sources (dye lasers, solid state lasers, semiconductor lasers, fiber lasers, and sources based on frequency conversion). Provides an easy to follow guide through "faster than electronics" probing and detection methods THE manual on designing and constructing femtosecond systems and experiments Discusses essential technology for applications in micro-machining, femtochemistry, and medical imaging
Download or read book Magnetic Fusion Technology written by Thomas J. Dolan and published by Springer Science & Business Media. This book was released on 2014-02-10 with total page 816 pages. Available in PDF, EPUB and Kindle. Book excerpt: Magnetic Fusion Technology describes the technologies that are required for successful development of nuclear fusion power plants using strong magnetic fields. These technologies include: • magnet systems, • plasma heating systems, • control systems, • energy conversion systems, • advanced materials development, • vacuum systems, • cryogenic systems, • plasma diagnostics, • safety systems, and • power plant design studies. Magnetic Fusion Technology will be useful to students and to specialists working in energy research.
Download or read book Solar Prominences written by Jean-Claude Vial and published by Springer. This book was released on 2014-11-24 with total page 490 pages. Available in PDF, EPUB and Kindle. Book excerpt: This volume presents the latest research results on solar prominences, including new developments on e.g. chirality, fine structure, magnetism, diagnostic tools and relevant solar plasma physics. In 1875 solar prominences, as seen out of the solar limb, were described by P.A. Secchi in his book Le Soleil as "gigantic pink or peach-flower coloured flames". The development of spectroscopy, coronagraphy and polarimetry brought tremendous observational advances in the twentieth century. The authors present and discuss exciting new challenges (resulting from observations made by space and ground-based telescopes in the 1990s and the first decade of the 21st century) concerning the diagnostics of prominences, their formation, their life time and their eruption along with their impact in the heliosphere (including the Earth). The book starts with a general introduction of the prominence “object” with some historical background on observations and instrumentation. In the next chapter, the various forms of prominences are described with a thorough attempt of classification. Their thermodynamic (and velocity) properties are then derived with emphasis on the methods (and their limits) used. This goes from the simplest optically thin case to the heavy radiative treatment of plasmas out of local thermodynamic equilibrium. The following chapters are devoted to the magnetic field measurements and indirect derivation. A new branch of diagnostic tools, the seismology, is presented along with some MHD basics. This allows to better understand the propagation of waves, the energy and force equilibria. Both small-scale and large-scale studies and their relationship are presented. The importance of the newly discovered cavities is stressed in the context of prominence destabilization. The issues of prominence formation and eruption, their connection with flares and Coronal Mass Ejections and their impact on the Earth are addressed on the basis of the latest results. Finally, an exciting new area of research is unveiled with the newly discovered evidence of similar manifestations in the Universe and their possible impact on the habitability of exoplanets. References to the basic physics (where necessary) are provided and the proposed web sites addresses will allow the reader to load exciting movies. The book is aimed at advanced students in astrophysics, post-graduates, solar physicists and more generally astrophysicists. Amateurs will enjoy the many new images which go with the text.
Download or read book Electronic Structure of Quantum Confined Atoms and Molecules written by K.D. Sen and published by Springer. This book was released on 2014-09-19 with total page 260 pages. Available in PDF, EPUB and Kindle. Book excerpt: The present volume is a collection of review articles highlighting the fundamental advances made in this area by the internationally acclaimed research groups , most of them being pioneers themselves and coming together for the first time.
