Download or read book Transport of Particles and Energy in the Edge Plasma of the Alcator C Mod Tokamak written by Maxim V. Umansky and published by . This book was released on 1999 with total page 131 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Investigation of Triggering Mechanism of Internal Transport Barriers on the Alcator C Mod Tokamak Using Thomson Scattering Diagnostic written by Kirill Zhurovich and published by . This book was released on 2007 with total page 185 pages. Available in PDF, EPUB and Kindle. Book excerpt: Internal transport barriers (ITBs) in tokamak plasmas are characterized by the reduction of transport in one or more of the particle, momentum, or energy channels in the core plasma region. On Alcator C-Mod, significant contributions to ITB studies were made possible with the core Thomson scattering (TS) diagnostic, which measures profiles of electron temperature (0.03
Download or read book Particle Transport on the Alcator C Mod Tokamak written by Cindy R. Christensen and published by . This book was released on 1999 with total page 184 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Driven Rotation Self Generated Flow and Momentum Transport in Tokamak Plasmas written by John Rice and published by Springer Nature. This book was released on 2022-01-13 with total page 158 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book provides a comprehensive look at the state of the art of externally driven and self-generated rotation as well as momentum transport in tokamak plasmas. In addition to recent developments, the book includes a review of rotation measurement techniques, measurements of directly and indirectly driven rotation, momentum sinks, self-generated flow, and momentum transport. These results are presented alongside summaries of prevailing theory and are compared to predictions, bringing together both experimental and theoretical perspectives for a broad look at the field. Both researchers and graduate students in the field of plasma physics will find this book to be a useful reference. Although there is an emphasis on tokamaks, a number of the concepts are also relevant to other configurations.
Download or read book Impurity Plume Experiments in the Edge Plasma of the Alcator C Mod Tokamak written by Sanjay Gangadhara and published by . This book was released on 2003 with total page 86 pages. Available in PDF, EPUB and Kindle. Book excerpt: The physics of impurity transport in response to a local gas injection in the scrape-off-layer (SOL) of Alcator C-Mod is investigated. Carbon "plumes'' are formed at variable locations in the SOL -- up to the separatrix -- by puffing deuterated ethylene gas (C2D4) through the end of a reciprocating fast-scanning probe. CCD cameras are used to simultaneously record C+1 and C+2 emission patterns from two near-perpendicular views. The plume dispersal patterns are found to yield direct qualitative information about plasma flow, including the direction of VExB near the separatrix. Impurity transport and plasma-surface interaction physics implicit in the 3-D plume structure is explored in detail using a Monte Carlo impurity transport code, with the aim of extracting background plasma-flow quantities. A number of important local effects involving plasma-probe interaction have been identified: a vertical ExB drift near the probe surface, a parallel electric field above the probe tip arising from plasma recycling off the probe surface, and sputtering of a carbon layer that dynamically forms on the probe surface. The emission patterns are also found to yield important information on flows in the SOL: radial electric field (Er) in the near SOL and volume-averaged values of the parallel Mach number in the far SOL. Er values obtained from plume data compare favorably with estimates of Er based on the poloidal propagation velocity of edge plasma fluctuations measured by the scanning probe. Comparisons between parallel Mach numbers obtained from the plume data and probe measurements indicate that the probe over-estimates the parallel flow towards the divertor in the far SOL. This result supports the picture of particle balance in the SOL of Alcator C-Mod being dominated by main-chamber recycling, with weak plasma flow into the divertor.
Download or read book Edge Transport Barrier Studies on the Alcator C Mod Tokamak written by Jerry Wayne Hughes and published by . This book was released on 2005 with total page 452 pages. Available in PDF, EPUB and Kindle. Book excerpt: Edge transport barriers (ETBs) in tokamak plasmas accompany transitions from low confinement (L-mode) to high confinement (H-mode) and exhibit large density and temperature gradients in a narrow pedestal region near the last closed flux surface (LCFS). Because tokamak energy confinement depends strongly on the boundary condition imposed by the edge plasma pressure, one desires a predictive capability for the pedestal on a future tokamak. On Alcator C-Mod, significant contributions to ETB studies were made possible with edge Thomson scattering (ETS), which measures profiles of electron temperature (20 [leq] Te[eV] [leq] 800) and density (0.3 [leq] ne[10^20m^-3] [leq] 5) with 1.3-mm spatial resolution near the LCFS. Profiles of Te, ne, and pe = neTe are fitted with a parameterized function, revealing typical pedestal widths [delta] of 2-6mm, with [delta]Te [geq] [delta]ne , on average. Pedestals are examined to determine existence criteria for the enhanced D[alpha] (EDA) H-mode. A feature that distinguishes this regime is a quasi-coherent mode (QCM) near the LCFS. The presence or absence of the QCM is related to edge conditions, in particular density, temperature and safety factor q. Results are consistent with higher values of both q and collisionality [nu]* giving the EDA regime. Further evidence suggests that increased abs([nabla]pe) may favor the QCM; thus EDA may have relevance to low-[nu]* reactor regimes, should sufficient edge pressure gradient exist.
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 Issues in Nuclear High Energy Plasma Particle and Condensed Matter Physics 2013 Edition written by and published by ScholarlyEditions. This book was released on 2013-05-01 with total page 1198 pages. Available in PDF, EPUB and Kindle. Book excerpt: Issues in Nuclear, High Energy, Plasma, Particle, and Condensed Matter Physics: 2013 Edition is a ScholarlyEditions™ book that delivers timely, authoritative, and comprehensive information about High Energy Physics. The editors have built Issues in Nuclear, High Energy, Plasma, Particle, and Condensed Matter Physics: 2013 Edition on the vast information databases of ScholarlyNews.™ You can expect the information about High Energy Physics in this book to be deeper than what you can access anywhere else, as well as consistently reliable, authoritative, informed, and relevant. The content of Issues in Nuclear, High Energy, Plasma, Particle, and Condensed Matter Physics: 2013 Edition has been produced by the world’s leading scientists, engineers, analysts, research institutions, and companies. All of the content is from peer-reviewed sources, and all of it is written, assembled, and edited by the editors at ScholarlyEditions™ and available exclusively from us. You now have a source you can cite with authority, confidence, and credibility. More information is available at http://www.ScholarlyEditions.com/.
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 On the Edge of Magnetic Fusion Devices written by Sergei Krasheninnikov and published by Springer Nature. This book was released on 2020-09-07 with total page 269 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book reviews the current state of understanding concerning edge plasma, which bridges hot fusion plasma, with a temperature of roughly one million degrees Kelvin with plasma-facing materials, which have melting points of only a few thousand degrees Kelvin. In a fact, edge plasma is one of the keys to solution for harnessing fusion energy in magnetic fusion devices. The physics governing the processes at work in the edge plasma involves classical and anomalous transport of multispecies plasma, neutral gas dynamics, atomic physics effects, radiation transport, plasma-material interactions, and even the transport of plasma species within the plasma-facing materials. The book starts with simple physical models, then moves on to rigorous theoretical considerations and state-of-the-art simulation tools that are capable of capturing the most important features of the edge plasma phenomena. The authors compare the conclusions arising from the theoretical and computational analysis with the available experimental data. They also discuss the remaining gaps in their models and make projections for phenomena related to edge plasma in magnetic fusion reactors.
Download or read book 108 1 Hearings Energy and Water Development Appropriations For 2004 Part 4 2003 written by and published by . This book was released on 2003 with total page 3122 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Energy and Impurity Transport in the Alcator C Tokamak written by Alcator Group and published by . This book was released on 1982 with total page 12 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book 107 2 Hearings Energy and Water Development Appropriations For 2003 Part 4 2002 written by and published by . This book was released on 2002 with total page 1512 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Study of the Effects of Neutrals in Alcator C Mod Plasmas written by and published by . This book was released on 1999 with total page 4 pages. Available in PDF, EPUB and Kindle. Book excerpt: Recently, much effort has been dedicated to understanding the bifurcation involved in the transition from a low to high confinement regime. While several theories have been brought forward, many factors remain to be elucidated, one of which involves the role played by neutral particles in the evolution of a transport barrier near the edge of the plasma. Alcator C-Mod is especially well suited for the study of neutral particle effects, mainly because of its high plasma and neutral densities, and closed divertor geometry. Alcator C-Mod employs ICRF as auxiiiary heating for obtaining a high confinement regime, although ohmic H-modes are routinely obtained as well. The neutrals can enter the edge dynamics through the particle, momentum and energy balance. In the particle balance, the source of neutrals has to be evaluated vis-8-vis the formation of the edge density pedestal. It is widely believed that plasma rotation is an important factor in reducing transport. In this case, neutrals could act as a momentum sink, through the charge-exchange process. That same process can also modify the energy balance of the plasma near the edge by increasing the cross-field heat flux. These effects are quite difficult to measure experimentally, in large part because neutral particle diagnosis is not an easy task, and because of the inherent 3-dimensional aspect of the problem. Consequently, the neutral s spatial and energy distributions are usually not well known. In Alcator C-Mod, we recently implemented a series of diagnostics for the purpose of measuring these distributions. They include measurements of the neutral pressure at many locations around the tokamak, and spatially resolved measurements of Lyman-a and charge-exchange power emission. A high-resolution multichord (20 channels) tangential view of neutral deuterium emission (Lyman-a) has been recently installed near the midplane. The viewing area covers approximately 4 cm across the separatrix, with a nominal 2 mm radial resolution. Standard Abel inversion techniques give the local Lyman-a emission. In conjunction with electron density and temperature, we can infer the local ionization rate and neutral density profiles. Two types of bolometer arrays (16 channels each), one being sensitive and the other insensitive to power carried by neutrals, view the plasma cross-section, tangentially at the midplane of the tokamak. By Abel inverting the difference between the 2 measurements, we infer the local power emissivity carried by neutrals[11].
Download or read book Magnetic Fusion Energy written by George Neilson and published by Woodhead Publishing. This book was released on 2016-06-02 with total page 634 pages. Available in PDF, EPUB and Kindle. Book excerpt: Magnetic Fusion Energy: From Experiments to Power Plants is a timely exploration of the field, giving readers an understanding of the experiments that brought us to the threshold of the ITER era, as well as the physics and technology research needed to take us beyond ITER to commercial fusion power plants. With the start of ITER construction, the world’s magnetic fusion energy (MFE) enterprise has begun a new era. The ITER scientific and technical (S&T) basis is the result of research on many fusion plasma physics experiments over a period of decades. Besides ITER, the scope of fusion research must be broadened to create the S&T basis for practical fusion power plants, systems that will continuously convert the energy released from a burning plasma to usable electricity, operating for years with only occasional interruptions for scheduled maintenance. Provides researchers in academia and industry with an authoritative overview of the significant fusion energy experiments Considers the pathway towards future development of magnetic fusion energy power plants Contains experts contributions from editors and others who are well known in the field
Download or read book Energy and Water Development Appropriations for 2001 Department of Energy fiscal year 2001 budget justifications written by United States. Congress. House. Committee on Appropriations. Subcommittee on Energy and Water Development and published by . This book was released on 2000 with total page 3160 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Energy and Water Development Appropriations for 2001 written by United States. Congress. House. Committee on Appropriations. Subcommittee on Energy and Water Development and published by . This book was released on 2000 with total page 1552 pages. Available in PDF, EPUB and Kindle. Book excerpt:
