Download or read book Velocity ion Temperature Gradient Driven Modes and Angular Momentum Transport in Magnetically Confined Plasmas written by John Chandler Thomas and published by . This book was released on 2007 with total page 42 pages. Available in PDF, EPUB and Kindle. Book excerpt: Plasma confinement experiments continue to uncover fascinating phenomena that motivate theoretical discussion and exploration. In this thesis, we consider the phenomenon of angular momentum transport in magnetically confined plasmas. Relevant experiments and theoretical developments are presented in order to motivate the derivation of a modified version of the three-field nonlinear Hamaguchi-Horton equations. The equations are altered to include a zeroth-order parallel velocity inhomogeneity along the radially-analogous coordinate, resulting in a nonlinear system that describes the evolution of the velocity-ion temperature gradient-driven modes (VITGs). The equations are used to analyze VITG modes in the local approximation of a magnetized plasma, as well as in an inhomogeneous slab model. Applying quasilinear methods, we find a turbulent angular momentum flux in agreement with the accretion theory of the spontaneous rotation phenomenon. More advanced applications are considered for future analysis.

Download or read book Turbulent Transport in Magnetized Plasmas written by Wendell Horton and published by World Scientific. This book was released on 2012 with total page 518 pages. Available in PDF, EPUB and Kindle. Book excerpt: The book explains how magnetized plasmas self-organize in states of electromagnetic turbulence that transports particles and energy out of the core plasma faster than anticipated by the fusion scientists designing magnetic confinement systems in the 20th century. It describes theory, experiments and simulations in a unified and up-to-date presentation of the issues of achieving nuclear fusion power.

Download or read book Magnetic Compressibility and Ion temperature gradient driven Microinstabilities in Magnetically Confined Plasmas written by and published by . This book was released on 2015 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Ion Temperature Gradient Driven Turbulent and Transport in a Sheared Magnetic Field written by and published by . This book was released on 1990 with total page 34 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Fusion Physics written by MITSURU KIKUCHI and published by International Atomic Energy. This book was released on 2002-01-01 with total page 1158 pages. Available in PDF, EPUB and Kindle. Book excerpt: Humans do not live by bread alone. Physically we are puny creatures with limited prowess, but with unlimited dreams. We see a mountain and want to move it to carve out a path for ourselves. We see a river and want to tame it so that it irrigates our fields. We see a star and want to fly to its planets to secure a future for our progeny. For all this, we need a genie who will do our bidding at a flip of our fingers. Energy is such a genie. Modern humans need energy and lots of it to live a life of comfort. In fact, the quality of life in different regions of the world can be directly correlated with the per capita use of energy [1.1–1.5]. In this regard, the human development index (HDI) of various countries based on various reports by the United Nations Development Programme (UNDP) [1.6] (Fig. 1.1), which is a parameter measuring the quality of life in a given part of the world, is directly determined by the amount of per capita electricity consumption. Most of the developing world (~5 billion people) is crawling up the UN curve of HDI versus per capita electricity consumption, from abysmally low values of today towards the average of the whole world and eventually towards the average of the developed world. This translates into a massive energy hunger for the globe as a whole. It has been estimated that by the year 2050, the global electricity demand will go up by a factor of up to 3 in a high growth scenario [1.7–1.9]. The requirements beyond 2050 go up even higher.

Download or read book Turbulent Transport In Magnetized Plasmas written by C Wendell Horton, Jr and published by World Scientific. This book was released on 2012-08-22 with total page 518 pages. Available in PDF, EPUB and Kindle. Book excerpt: The book explains how magnetized plasmas self-organize in states of electromagnetic turbulence that transports particles and energy out of the core plasma faster than anticipated by the fusion scientists designing magnetic confinement systems in the 20th century. It describes theory, experiments and simulations in a unified and up-to-date presentation of the issues of achieving nuclear fusion power.

Download or read book Turbulence in Toroidally Confined Plasma written by Gyung Su Lee and published by . This book was released on 1986 with total page 224 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Collisional and Electromagnetic Physics in Gyrokinetic Models written by Paul Crandall and published by . This book was released on 2019 with total page 229 pages. Available in PDF, EPUB and Kindle. Book excerpt: One of the most challenging problems facing plasma physicists today involves the modeling of plasma turbulence and transport in magnetic confinement experiments. The most successful model to this end so far is the reduced gyrokinetic model. Such a model cannot be solved analytically, but can be used to simulate the plasma behavior and transport with the help of present-day supercomputers. This has lead to the development of many different codes which simulate the plasma using the gyrokinetic model in various ways. These models have achieved a large amount of success in describing the core of the plasma for conventional tokamak devices. However, numerous difficulties have been encountered when applying these models to more extreme parameter regimes, such as the edge and scrape-off layer of the tokamak, and high plasma devices, such as spherical tokamaks. The development and application of the gyrokinetic model (specifically with the gyrokinetic code, GENE) to these more extreme parameter ranges shall be the focus of this thesis. One of the main accomplishments during this thesis project is the development of a more advanced collision operator suitable for studying the low temperature plasma edge. The previous collision operator implemented in the code was found to artificially create free energy at high collisionality, leading to numerical instabilities when one attempted to model the plasma edge. This made such an analysis infeasible. The newly implemented collision operator conserves particles, momentum, and energy to machine precision, and is guaranteed to dissipate free energy, even in a nonisothermal scenario. Additional finite Larmor radius correction terms have also been implemented in the local code, and the global code version of the collision operator has been adapted for use with an advanced block-structured grid scheme, allowing for more affordable collisional simulations. The GENE code, along with the newly implemented collision operator developed in this thesis, has been applied to study plasma turbulence and transport in the edge (tor = 0:9) of an L-mode magnetic confinement discharge of ASDEX Upgrade. It has been found that the primary microinstabilities at that radial position are electron drift waves destabilized by collisions and electromagnetic effects. At low toroidal mode numbers, ion temperature gradient driven modes and microtearing modes also seem to exist. In nonlinear simulations with the nominal experimental parameters, the simulated electron heat flux was four times higher than the experimental reconstruction, and the simulated ion heat flux was twice as high. However, both the ion and electron simulated heat flux could be brought into agreement with experimental values by lowering the input logarithmic electron temperature gradient by 40%. It was also found that the cross-phases between the electrostatic potential and the moments agreed well for the part of the binormal spectrum where the dominant transport occurred, and was fairly poor at larger scales where minimal transport occurred. Finally, a new scheme for evaluating the electromagnetic fields has been developed to address the instabilities occurring in nonlinear local and global gyrokinetic simulations at high plasma . This new scheme is based on evaluating the electromagnetic induction explicitly, and constructing the gyrokinetic equation based on the original distribution, rather than the modified distribution which implicitly takes into account the induction. This new scheme removes the artificial instability occurring in global simulations, enabling the study of high scenarios with GENE. The new electromagnetic scheme can also be generalized to a full-f implementation, however, it would require updating the field matrix every time-step to avoid the cancellation problem. The new scheme (including the parallel nonlinearity) does not remove the local instability, suggesting that that instability (caused by magnetic field perturbations shorting out zonal flows) is part of the physics of the local model.

Download or read book Size Scaling of Turbulent Transport in Magnetically Confined Plasmas written by Zhihong Lin and published by . This book was released on 2002 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Fusi n Nuclear written by and published by . This book was released on 2004-12 with total page 504 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Scientific and Technical Aerospace Reports written by and published by . This book was released on 1989 with total page 988 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Computational Methods for Kinetic Models of Magnetically Confined Plasmas written by J. Killeen and published by Springer. This book was released on 1986-04 with total page 216 pages. Available in PDF, EPUB and Kindle. Book excerpt: Because magnetically confined plasmas are generally not found in a state of thermodynamic equilibrium, they have been studied extensively with methods of applied kinetic theory. In closed magnetic field line confinement devices such as the tokamak, non-Maxwellian distortions usually occur as a result of auxiliary heating and transport. In magnetic mirror configurations even the intended steady state plasma is far from local thermodynamic equilibrium because of losses along open magnetic field lines. In both of these major fusion devices, kinetic models based on the Boltzmann equation with Fokker-Planck collision terms have been successful in representing plasma behavior. The heating of plasmas by energetic neutral beams or microwaves, the production and thermalization of a-particles in thermonuclear reactor plasmas, the study of runaway electrons in tokamaks, and the performance of two-energy compo nent fusion reactors are some examples of processes in which the solution of kinetic equations is appropriate and, moreover, generally necessary for an understanding of the plasma dynamics. Ultimately, the problem is to solve a nonlinear partial differential equation for the distribution function of each charged plasma species in terms of six phase space variables and time. The dimensionality of the problem may be reduced through imposing certain symmetry conditions. For example, fewer spatial dimensions are needed if either the magnetic field is taken to be uniform or the magnetic field inhomogeneity enters principally through its variation along the direction of the field.

Download or read book MHD and Microinstabilities in Confined Plasma written by Wallace M. Manheimer and published by CRC Press. This book was released on 1989 with total page 312 pages. Available in PDF, EPUB and Kindle. Book excerpt: Magnetohydrodynamics, the study of the motion of electrically conducting fluids in magnetic fields, is an important area in plasma physics. The effects of instabilities in such electrical fluids are very difficult to calculate and this is the first book to deal with the subject as a whole in a detailed manner. MHD and Microinstabilities in Confined Plasma starts from first principles and builds up to a full understanding of MHD. It features a number of topics not covered in other books on plasma, including non-linear theory, anomalous transport and magnetic reconnection.

Download or read book Fusion Energy Update written by and published by . This book was released on 1986 with total page 134 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Energy Research Abstracts written by and published by . This book was released on 1993 with total page 490 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Physics Letters written by and published by . This book was released on 1998 with total page 442 pages. Available in PDF, EPUB and Kindle. Book excerpt: General physics, atomic physics, molecular physics, and solid state physics.

Download or read book Turbulent Particle and Thermal Transport in Magnetized Plasmas written by Xiangrong Fu and published by . This book was released on 2013 with total page 306 pages. Available in PDF, EPUB and Kindle. Book excerpt: The particle and thermal transport by low-frequency drift waves in magnetized plasmas are studied with theories and simulations. Universal in inhomogeneous plasmas, drift waves in Earth's ionosphere, the GAMMA-10 Tandem Mirror machine, the Columbia Linear Machine and C-Mod tokamak are studied in this thesis. The first investigations are E x B particle transport in the given electric and magnetic fields of the GAMMA-10 mirror machine at the University of Tsukuba in Japan. The results show that the formation of E [subscript r]-shear by local heating of electrons can reduced the radial particle loss. The turbulent impurity particle transport driven by various modes in the MIT tokamak Alcator C-Mod is studied by a quasilinear theory and compared to experimental measurement of Boron density profiles. A code is developed for solving eigensystems of drift wave turbulence equations for the multi-component fusion plasmas and calculating quasilinear particle fluxes. The calculations are much faster than nonlinear simulations and may be suitable for real-time analysis and feedback control of tokamak plasmas. The electron temperature gradient (ETG) mode is a candidate mechanism for anomalous electron thermal transport across various magnetic confinement geometries. This mode was produced in the Columbia Linear Machine (CLM) at Columbia University. Large scale simulations of the ETG mode in the CLM by a gyrokinetic code GTC are carried out on supercomputers at TACC and NERSC. The results show good agreement with experiments in the dominant mode number, wave frequencies and the radial structure. Some nonlinear properties are also analyzed using the code.