Download or read book Energetic Particles in Tokamak Plasmas written by Sergei Sharapov and published by CRC Press. This book was released on 2021-04-02 with total page 156 pages. Available in PDF, EPUB and Kindle. Book excerpt: The study of energetic particles in magnetic fusion plasmas is key to the development of next-generation "burning" plasma fusion experiments, such as the International Thermonuclear Experimental Reactor (ITER) and the Demonstration Power Station (DEMO). This book provides a comprehensive introduction and analysis of the experimental data on how fast ions behave in fusion-grade plasmas, featuring the latest ground-breaking results from world-leading machines such as the Joint European Torus (JET) and the Mega Ampere Spherical Tokamak (MAST). It also details Alfvenic instabilities, driven by energetic ions, which can cause enhanced transport of energetic ions. MHD spectroscopy of plasma via observed Alfvenic waves called "Alfvén spectroscopy" is introduced and several applications are presented. This book will be of interest to graduate students, researchers, and academics studying fusion plasma physics. Features: Provides a comprehensive overview of the field in one cohesive text, with the main physics phenomena explained qualitatively first. Authored by an authority in the field, who draws on his extensive experience of working with energetic particles in tokamak plasmas. Is suitable for extrapolating energetic particle phenomena in fusion to other plasma types, such as solar and space plasmas.
Download or read book Energetic Particles in Spherical Tokamak Plasmas written by and published by . This book was released on 2017 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Energetic Particles in Tokamak Plasmas written by Sergei Sharapov and published by CRC Press. This book was released on 2021-03-18 with total page 152 pages. Available in PDF, EPUB and Kindle. Book excerpt: The study of energetic particles in magnetic fusion plasmas is key to the development of the next generation of "burning" plasma fusion experiments, such as the International Thermonuclear Experimental Reactor (ITER) and the Demonstration Power Station (DEMO). This book provides a comprehensive introduction and analysis of the latest experimental data on how fast ions behave in fusion grade plasmas, featuring the latest ground-breaking results from world leading machines such as the Joint European Torus (JET) and the Mega Ampere Spherical Tokamak (MAST). It also details Alfvenic instabilities, driven by energetic ions, which could cause the stochastic transport of energetic ions. MHD spectroscopy of plasma via observed Alfvenic waves and called "Alfvén spectroscopy" is introduced and several applications are presented. This book will be of interest to graduate students, researchers, and academics studying fusion plasma physics. Key Features: Provides a comprehensive overview of the field in one cohesive text, with main physics phenomena explained qualitatively first Authored by an authority in the field, who draws on his extensive experience of working with energetic particles in fusion plasmas Is suitable for extrapolating energetic particle phenomena in fusion to other types of plasmas, such as solar and space plasmas
Download or read book Global Hybrid Simulations of Energetic Particle Driven Modes in Toroidal Plasmas written by G. Y. Fu and published by . This book was released on 2004 with total page 12 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Theory of Tokamak Plasmas written by R.B. White and published by Elsevier. This book was released on 2017-01-31 with total page 374 pages. Available in PDF, EPUB and Kindle. Book excerpt: This is a graduate textbook on tokamak physics, designed to provide a basic introduction to plasma equilibrium, particle orbits, transport, and those ideal and resistive magnetohydrodynamic instabilities which dominate the behavior of a tokamak discharge, and to develop the mathematical methods necessary for their theoretical analysis.
Download or read book The effect of energetic particles on stability of mirror and tokamak plasmas written by Daren Price Stotler and published by . This book was released on 1986 with total page 442 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Interaction Between Energetic Particles and Sawtooth Instabilities in Tokamak Plasmas written by Yi Zhao and published by . This book was released on 1997 with total page 240 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book MHD Spectroscopy of Tokamak Plasmas Using Alfv n Waves written by Henry James Churston Oliver and published by . This book was released on 2020 with total page 338 pages. Available in PDF, EPUB and Kindle. Book excerpt: Alfvén waves are electromagnetic waves that occur in magnetised plasmas. Alfvén waves are routinely observed in tokamaks — toroidal devices that confine plasma using magnets. Energetic ions that are used to heat the plasma within tokamaks can drive the Alfvén waves unstable. Additionally, alpha particles produced in fusion reactions may destabilise the wave. Alfvén waves with sufficiently high amplitudes can eject energetic particles from the plasma, damaging the reactor and decreasing fusion efficiency. When these waves are not strong enough to eject particles from the plasma, their benign behaviour can be used to diagnose the plasma. This technique is known as magnetohydrodynamic (MHD) spectroscopy. In this thesis, we outline three new techniques of MHD spectroscopy that we have developed. The first new method of MHD spectroscopy was developed in plasmas composed of hydrogen and deuterium in the Mega Ampere Spherical Tokamak (MAST). Compressional Alfvén eigenmodes (CAEs) and global Alfvén eigenmodes (GAEs) were suppressed in plasmas with high hydrogen concentrations. At the highest hydrogen concentrations investigated, high frequency ion-ion hybrid waves appeared. We used a 1D model of the refractive index and wave-particle resonances to explain these observations and estimate the relative ion concentration at which the spectrum of excited waves changed. These estimates agreed with experimental observations, suggesting the spectrum of excited waves can be used to diagnose the relative ion concentrations for plasmas with two ion species. The second new form of MHD spectroscopy was developed using observations of axisymmetric modes in experiments on the Joint European Torus (JET). Axisymmetric modes do not change in the toroidal direction and are driven unstable by energy gradients in the fast particle distribution function. Therefore, we can use observations of the axisymmetric mode to infer information about the gradient of the fast particle energy distribution function. We explained how these axisymmetric modes can exist without heavy damping. We also examined how the elongation of the plasma column modifies the mode using numerical and analytical tools. The final MHD spectroscopic technique was developed for JET plasmas injected with pellets of frozen deuterium, which are used to refuel the plasma core. We demonstrated how key pellet parameters can be inferred from dramatic changes to the Alfvén eigenfrequencies that we observed in JET. MHD spectroscopy of pellet injected plasmas was enabled by generalising two 3D MHD codes to incorporate 3D density profiles. 3D density profiles were generated using a model for the expansion of the pellet wake along a magnetic field line derived from the fluid equations. From the change in mode frequency, we estimate the density of the pellet wake and the time-scale for poloidal homogenisation of the wake. Before presenting these studies, we introduce the basics of fusion, tokamaks, and the models used to describe tokamak plasmas. We then discuss the MHD waves that we will use for MHD spectroscopy of tokamak plasmas, and how these waves are excited by fast particles. The three new methods of MHD spectroscopy are then discussed
Download or read book Energetic Particle Stabilization of Ballooning Modes in a Finite aspect ratio Tokamak written by Hiroshi Naitou and published by . This book was released on 1986 with total page 60 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Alpha Particle Energetics and Neutral Beam Heating in Tokamak Plasmas written by David George McAlees and published by . This book was released on 1974 with total page 302 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Fluid and Kinetic Descriptions of the Mutual Interaction Between Tearing Modes and Thermal and Energetic Particles in Tokamak Plasmas written by Sabine Nasr and published by . This book was released on 2018 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: The stability of collisionless tearing modes is analyzed in the presence of an inhomogeneous magnetic field in fluid and gyrokinetic theories. It is shown by means of a fluid model that small scale modes, characterized by a negative stability parameter (∆'≺0), can be driven unstable due to a combination of the magnetic field and electron temperature gradients. The destabilization mechanism is identified as of the interchange type, similar to that for toroidal ETG modes. The resonant interaction between the mode and different classes of particles is studied in gyrokinetic theory. It is found that curvature and magnetic field inhomogeneity effectively change the mode stability through trapped particles. This is verified numerically with a gyrokinetic code (GKW) where the interchange-like destabilization is confirmed. Furthermore, the impact of a population of energetic particles is investigated. Linearly, using a gyrokinetic model, the particular case of energetic particle distribution presenting anisotropy in the temperature is taken into account. Non-linearly, the impact of the time evolution of the energetic particle density on the growth of magnetic islands is examined by means of a fluid model.
Download or read book Diamagnetic Fishbone Mode Associated with Circulating Fast Ions in Spherical Tokamaks written by Ya. I. Kolesnichenko and published by . This book was released on 2001 with total page 9 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Plasma Science written by National Academies of Sciences Engineering and Medicine and published by . This book was released on 2021-02-28 with total page 291 pages. Available in PDF, EPUB and Kindle. Book excerpt: Plasma Science and Engineering transforms fundamental scientific research into powerful societal applications, from materials processing and healthcare to forecasting space weather. Plasma Science: Enabling Technology, Sustainability, Security and Exploration discusses the importance of plasma research, identifies important grand challenges for the next decade, and makes recommendations on funding and workforce. This publication will help federal agencies, policymakers, and academic leadership understand the importance of plasma research and make informed decisions about plasma science funding, workforce, and research directions.
Download or read book Test Particle Studies of Acceleration and Transport in Solar and Tokamak Plasmas written by Robert McKay and published by . This book was released on 2009 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: A test particle approach is used to study two distinct plasma physics situations. In the first case, the collisionless response of protons to cold plasma fast Alfven waves propagating in a non-uniform magnetic field configuration (specifically, a two-dimensional X-point field) is studied. The field perturbations associated with the waves, which are assumed to be azimuthally-symmetric and invariant in the direction orthogonal to the X-point plane, are exact solutions of the linearized ideal magnetohydrodynamic (MHD) equations. The protons are initially Maxwellian, at temperatures that are consistent with the cold plasma approximation. Two kinds of wave solution are invoked: global perturbations, with inward- and outward-propagating components; and purely inward-propagating waves, localised in distance from the X-point null, the wave electric field E having a preferred direction. In both cases the protons are effectively heated in the direction parallel to the magnetic field, although the parallel velocity distribution is generally non-Maxwellian and some protons are accelerated to highly suprathermal energies. This heating and acceleration can be attributed to the fact that protons undergoing E x B drifts due to the presence of the wave are subject to an effective force in the direction parallel to B. The localised wave solution produces more effective proton heating than the global solution, and successive wave pulses have a synergistic effect. This process, which could play a role in both solar coronal heating and late-phase heating in solar flares, is effective for all ion species, but has a negligible direct effect on electrons. However, both electrons and heavy ions would be expected to acquire a temperature similar to that of the protons on collisional timescales. In the second case the same approach is used to study the collisional transport of impurity ions (carbon, mainly, although tungsten ions are also simulated) in spherical tokamak (ST) plasmas with transonic and subsonic toroidal flows. The efficacy of this approach is demonstrated by reproduscing the results of classical transport theory in the large aspect ratio limit. The equilibrium parameters used in the ST modelling are similar to those of plasmas in the MAST experiment. The effects on impurity ion confinement of both counter-current and co-current rotation are determined. Various majority ion density and temperature profiles, approximating measured profiles in rotating and non-rotating MAST plasmas, are used in the modelling. It is shown that transonic rotation (both counter-current and co-current) has the effect of reducing substantially the confinement time of the impurity ions. This effect arises primarily because the impurity ions, displaced by the centrifugal force to the low-field region of the tokamak, are subject to a collisional diffusivity that is greater than the flux surface-averaged value of this quantity. for a given set of plasma profiles, the carbon ions are found to be significantly less well-confined in co-rotating plasmas than in counter-rotating plasmas, although the difference in confinement time between co- and counter-rotation lessens as the mass of the impurity increases. In the case of carbon ions the poloidal distribution of losses exhibits a pronounced up/down asymmetry that is consistent with the direction of the net vertical drift of the impurity ions. Increasing the mass of the impurity ion is also found to significantly decrease the confinement time in the rotating cases, though the confinement time for the case of a stationary plasma is increased. Such studies of impurity transport within tokamaks are important because it is desirable to expel impurity ions from the plasma to avoid both dilution of the fuel ions and unacceptable radiation losses from the plasma.
Download or read book Introduction to Plasma Physics written by R.J Goldston and published by CRC Press. This book was released on 2020-07-14 with total page 514 pages. Available in PDF, EPUB and Kindle. Book excerpt: Introduction to Plasma Physics is the standard text for an introductory lecture course on plasma physics. The text’s six sections lead readers systematically and comprehensively through the fundamentals of modern plasma physics. Sections on single-particle motion, plasmas as fluids, and collisional processes in plasmas lay the groundwork for a thorough understanding of the subject. The authors take care to place the material in its historical context for a rich understanding of the ideas presented. They also emphasize the importance of medical imaging in radiotherapy, providing a logical link to more advanced works in the area. The text includes problems, tables, and illustrations as well as a thorough index and a complete list of references.
Download or read book Effects of Energetical Particles on Ballooning Modes in High Temperature Tokamaks Final Report August 1990 August 1991 written by and published by . This book was released on 1992 with total page 16 pages. Available in PDF, EPUB and Kindle. Book excerpt: This report describes the work done by Science Applications International Corporation to study the effects of energetic particles on the microstability of a high temperature tokamak. The effects of an energetic population on ballooning modes in a large aspect ratio, shifted circular flux surface tokamak equilibrium are investigated with the newly developed gryokinetic numerical technique. The gryokinetic equations for the background ion and electron, as well as that of the energetic population are solved directly as an initial problem. The energetic particles are modeled with a slow-down distribution in energy. It is found that the ballooning mode stability of the plasma with an energetic species of increasing concentration does not differ much from an increase in the background plasma beta, except for possible energetic particle drift resonances. This result is encouraging to the idea that energetic particles such as alphas may be used to stabilize the ballooning modes in a fusion reactor.
Download or read book Collisional and Chaotic Transport of Energetic Particles in Toroidal Plasma written by and published by . This book was released on 1992 with total page 10 pages. Available in PDF, EPUB and Kindle. Book excerpt: We have made progress in three general areas of confinement plasma physics is proposed. We developed an accurate theory for the trapping/detrapping process in tokamaks with ripple and stellarators. We determined the alpha particle distribution in the situation where both collisions and collisionless chaotic (ripple) transport are present.
