Download or read book Experimental Investigation of Active Feedback Control of Turbulent Transport in a Magnetized Plasma written by and published by . This book was released on 2013 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: A new and unique basic plasma science laboratory device - the HelCat device (HELicon-CAThode) - has been constructed and is operating at the University of New Mexico. HelCat is a 4 m long, 0.5 m diameter device, with magnetic field up to 2.2 kG, that has two independent plasmas sources - an RF helicon source, and a thermionic cathode. These two sources, which can operate independently or simultaneously, are capable of producing plasmas with a wide range of parameters and turbulence characteristics, well suited to a variety of basic plasma physics experiments. An extensive set of plasma diagnostics is also operating. Experiments investigating the active feedback control of turbulent transport of particles and heat via electrode biasing to affect plasma ExB flows are underway, and ongoing.

Download or read book Numerical and Experimental Investigation of Turbulent Transport Control Via Shaping of Radial Plasma Flow Profiles written by and published by . This book was released on 2017 with total page 73 pages. Available in PDF, EPUB and Kindle. Book excerpt: Turbulence, and turbulence-driven transport are ubiquitous in magnetically confined plasmas, where there is an intimate relationship between turbulence, transport, instability driving mechanisms (such as gradients), plasma flows, and flow shear. Though many of the detailed physics of the interrelationship between turbulence, transport, drive mechanisms, and flow remain unclear, there have been many demonstrations that transport and/or turbulence can be suppressed or reduced via manipulations of plasma flow profiles. This is well known in magnetic fusion plasmas [e.g., high confinement mode (H-mode) and internal transport barriers (ITB's)], and has also been demonstrated in laboratory plasmas. However, it may be that the levels of particle transport obtained in such cases [e.g. H-mode, ITB's] are actually lower than is desirable for a practical fusion device. Ideally, one would be able to actively feedback control the turbulent transport, via manipulation of the flow profiles. The purpose of this research was to investigate the feasibility of using both advanced model-based control algorithms, as well as non-model-based algorithms, to control cross-field turbulence-driven particle transport through appropriate manipulation of radial plasma flow profiles. The University of New Mexico was responsible for the experimental portion of the project, while our collaborators at the University of Montana provided plasma transport modeling, and collaborators at Lehigh University developed and explored control methods.

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 Final Technical Report written by and published by . This book was released on 2014 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: The strong coupling between the different physical variables involved in the plasma transport phenomenon and the high complexity of its dynamics call for a model-based, multivariable approach to profile control where those predictive models could be exploited. The overall objective of this project has been to extend the existing body of work by investigating numerically and experimentally active control of unstable fluctuations, including fully developed turbulence and the associated cross-field particle transport, via manipulation of flow profiles in a magnetized laboratory plasma device. Fluctuations and particle transport can be monitored by an array of electrostatic probes, and Ex B flow profiles can be controlled via a set of biased concentric ring electrodes that terminate the plasma column. The goals of the proposed research have been threefold: i- to develop a predictive code to simulate plasma transport in the linear HELCAT (HELicon-CAThode) plasma device at the University of New Mexico (UNM), where the experimental component of the proposed research has been carried out; ii- to establish the feasibility of using advanced model-based control algorithms to control cross-field turbulence-driven particle transport through appropriate manipulation of radial plasma flow profiles, iii- to investigate the fundamental nonlinear dynamics of turbulence and transport physics. Lehigh University (LU), including Prof. Eugenio Schuster and one full-time graduate student, has been primarily responsible for control-oriented modeling and model-based control design. Undergraduate students have also participated in this project through the National Science Foundation Research Experience for Undergraduate (REU) program. The main goal of the LU Plasma Control Group has been to study the feasibility of controlling turbulence-driven transport by shaping the radial poloidal flow profile (i.e., by controlling flow shear) via biased concentric ring electrodes.

Download or read book Scientific and Technical Aerospace Reports written by and published by . This book was released on 1995 with total page 602 pages. Available in PDF, EPUB and Kindle. Book excerpt: Lists citations with abstracts for aerospace related reports obtained from world wide sources and announces documents that have recently been entered into the NASA Scientific and Technical Information Database.

Download or read book Nuclear Science Abstracts written by and published by . This book was released on 1975 with total page 764 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Experimental Investigation of Dynamical Coupling Between Turbulent Transport and Parallel Flows in the JET Plasma Boundary Region written by C. Hidalgo and published by . This book was released on 2004* with total page 23 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 1995 with total page 782 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Documentation of Plasma Physics Pt 1 Experimental Plasma Physics and Theoretical Plasma Physics written by and published by . This book was released on 1980 with total page 416 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Fusion Energy Update written by and published by . This book was released on 1978 with total page 310 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Experimental study of the zonal flow dynamics in the magnetised plasmas of the stellarator experiment TJ K written by Bernhard Schmid and published by Cuvillier Verlag. This book was released on 2019-03-28 with total page 194 pages. Available in PDF, EPUB and Kindle. Book excerpt: The confinement quality of plasmas in toroidal magnetic fields is mainly limited by the turbulent transport perpendicular to the magnetic field. Zonal flows play an important role in fusion research as they are thought to be connected to the formation of a transport barrier in the edge of the confined plasma. This work concentrates on the investigation of the Reynolds stress drive of zonal flows with its connection to the geometry of the confining magnetic field and the influence of the collisionality. The measurements for this work have been conducted at the stellarator experiment TJ-K in plasmas dimensionally similar to fusion edge plasmas. The low temperatures allow the use of Langmuir probes in the entire confinement region. With a poloidal probe array, consisting of 128 Langmuir probes with 32 probes on each of four neighbouring magnetic flux surfaces, density and potential fluctuations can be acquired with high spatial and temporal resolution on the complete poloidal circumference. Die Einschlussqualität von Plasmen in toroidalen Magnetfeldern wird maßgeblich durch den turbulenten Transport senkrecht zum Magnetfeld limitiert. Zonalströmungen sind dabei für die Fusionsforschung von großer Bedeutung, da vermutet wird, dass sie mit der Bildung von Transportbarrieren in Zusammenhang stehen. Diese Arbeit beschäftigt sich vorwiegend mit der Untersuchung des Antriebsmechanismus von Zonalströmungen, im Speziellen mit der Abhängigkeit von der Magnetfeldgeometrie und dem Einfluss der Kollisionalität. Dazu wurden Messungen am Stellarator-Experiment TJ-K durchgeführt, in Plasmen, die dimensional ähnlich zu Randplasmen von Fusionsexperimenten sind. Die relativ geringen Plasmatemperaturen erlauben den Einsatz von Langmuir-Sonden im gesamten Einschlussgebiet. Mit einem poloidalen Sonden Array, bestehend aus 128 Sonden mit je 32 Sonden auf vier benachbarten Flussflächen, können Dichte- und Potentialfluktuationen mit hoher räumlicher und zeitlicher Auflösung gleichzeitig über den gesamten poloidalen Umfang aufgenommen werden.

Download or read book International Aerospace Abstracts written by and published by . This book was released on 1998 with total page 614 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Plasma Physics Index written by and published by . This book was released on 1979 with total page 820 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Applied Mechanics Reviews written by and published by . This book was released on 1994 with total page 390 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Turbulent Transport in Magnetized Plasmas written by Claude Wendell Horton and published by . This book was released on 2017 with total page 522 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.

Download or read book 107 1 Hearings Energy and Water Development Appropriations for 2002 Part 4 2001 written by and published by . This book was released on 2001 with total page 1476 pages. Available in PDF, EPUB and Kindle. Book excerpt:

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.