Read Books Online and Download eBooks, EPub, PDF, Mobi, Kindle, Text Full Free.
Divertor Heat And Particle Control Experiments On The Diii D Tokamak
Download Divertor Heat And Particle Control Experiments On The Diii D Tokamak full books in PDF, epub, and Kindle. Read online Divertor Heat And Particle Control Experiments On The Diii D Tokamak ebook anywhere anytime directly on your device. Fast Download speed and no annoying ads. We cannot guarantee that every ebooks is available!
Book Synopsis Divertor Heat and Particle Control Experiments on the DIII-D Tokamak by :
Download or read book Divertor Heat and Particle Control Experiments on the DIII-D Tokamak written by and published by . This book was released on 1994 with total page 39 pages. Available in PDF, EPUB and Kindle. Book excerpt: In this paper we present a summary of recent DIII-D divertor physics activity and plans for future divertor upgrades. During the past year, DIII-D experimental effort was focused on areas of active heat and particle control and divertor target erosion studies. Using the DIII-D Advanced Divertor system we have succeeded for the first time to control the plasma density and demonstrate helium exhaust in H-mode plasmas. Divertor heat flux control by means of D2 gas puffing and impurity injection were studied separately and in, both cases up to a factor of five reduction of the divertor peak heat flux was observed. Using the DiMES sample transfer system we have obtained erosion data on various material samples in well diagnosed plasmas and compared the results with predictions of numerical models.
Book Synopsis Divertor Research on the DIII-D Tokamak by :
Download or read book Divertor Research on the DIII-D Tokamak written by and published by . This book was released on 1994 with total page 15 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Book Synopsis Recent Results from the DIII-D Tokamak by :
Download or read book Recent Results from the DIII-D Tokamak written by and published by . This book was released on 1995 with total page 12 pages. Available in PDF, EPUB and Kindle. Book excerpt: The goal of the DIII-D program is to provide the integrated basis for commercially attractive steady state fusion power plants. Significant progress toward this goal has been achieved, enabled by system improvements including an error field correction coil, an expanded diagnostic set, a digital plasma control system, and high power rf systems. Simultaneous improvements in both the confinement and stability have been achieved during both VH-mode and negative central shear discharges. Fully non-inductive discharges with high bootstrap current fraction have been obtained. The divertor program has demonstrated simultaneous reduction of divertor heat flux and effective particle control using gas puffing and an in-vessel cryopump. Control of the wall particle inventory, He exhaust, and characterization of the scrapeoff layer and divertor plasma have been achieved. Progress has also been made in addressing additional specific needs for ITER: investigation of basic transport scaling, disruption characterization and avoidance, material erosion, and steady state beta limits.
Book Synopsis Advanced Tokamak Physics Experiments on DIII-D. by :
Download or read book Advanced Tokamak Physics Experiments on DIII-D. written by and published by . This book was released on 2001 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Significant reductions in the size and cost of a fusion power plant core can be realized if simultaneous improvements in the energy confinement time ([tau][sub E]) and the plasma pressure (or beta[beta][sub T]= 2[mu][sub 0] /B[sub T][sup 2]) can be achieved in steady-state conditions with high self driven bootstrap current fraction. In addition, effective power exhaust and impurity and particle control is required. Significant progress has been made in experimentally achieving regimes having the required performance in all of these aspects as well as in developing a theoretical understanding of the underlying physics. The authors have extended the duration of high performance ELMing H-mode plasmas with[beta][sub N] H[sub iop][approximately] 10 for 5[tau][sub E] ([approximately]1 s) and have demonstrated that core transport barriers can be sustained for the entire 5-s neutral beam duration in L-mode plasmas. Recent DIII-D work has advanced the understanding of improved confinement and internal transport barriers in terms of E x B shear stabilization of micro turbulence. With the aim of current profile control in discharges with negative central magnetic shear, they have demonstrated off-axis electron cyclotron current drive for the first time in a tokamak, finding an efficiency above theoretical expectations. MHD stability has been improved through shape optimization, wall stabilization, and modification of the pressure and current density profiles. Heat flux reduction and improved impurity and particle control have been realized through edge/divertor radiation and understanding and utilization of forced scrape off layer flow and divertor baffling.
Book Synopsis Recent DIII-D Divertor Research by :
Download or read book Recent DIII-D Divertor Research written by and published by . This book was released on 1995 with total page 12 pages. Available in PDF, EPUB and Kindle. Book excerpt: DIII-D currently operates with a single- or double-null open divertor and graphite walls. Active particle control with a divertor cryopump has demonstrated density control, efficient helium exhaust, and reduction of the inventory of particles in the wall. Gas puffing of D2 and impurities has demonstrated reduction of the peak divertor beat flux by factors of 3--5 by radiation. A combination of active cryopumping and feedback-controlled D2 gas puffing has produced similar divertor heat flux reduction with density control. Experiments with neon puffing have shown that the radiation is equally-divided between a localized zone near the X-point and a mantle around the plasma core. The density in these experiments has also been controlled with cryopumping. These experimental results combined with modeling were used to develop the new Radiative Divertor for DIII-D. This is a double-null slot divertor with four cryopumps to provide particle control and neutral shielding for high-triangularity advanced tokamak discharges. UEDGE and DEGAS simulations, benchmarked to experimental data, have been used to optimize the design.
Book Synopsis Scientific and Technical Aerospace Reports by :
Download or read book Scientific and Technical Aerospace Reports written by and published by . This book was released on 1995 with total page 548 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Book Synopsis Plasma Boundary Experiments on DIII-D Tokamak by :
Download or read book Plasma Boundary Experiments on DIII-D Tokamak written by and published by . This book was released on 1990 with total page 37 pages. Available in PDF, EPUB and Kindle. Book excerpt: A survey of the boundary physics research on the DIII-D tokamak and an outline of the DIII-D Advanced Divertor Program (ADP) is presented. We will present results of experiments on impurity control, impurity transport, neutral particle transport, and particle effects on core confinement over a wide range of plasma parameters, I{sub p}{approx lt} 3 MA, [beta]{sub T} {approx lt} 10.7%, P(auxiliary) {approx lt} 20 MW. Based on the understanding gained in these studies, we in collaboration with a number of other laboratories have devised a series of experiments (ADP) to modify the core plasma conditions through changes in the edge electric field, neutral recycling, and plasma surface interactions. 41 refs., 8 figs., 1 tab.
Book Synopsis Divertor Particle Exhaust and Wall Inventory on DIII-D. by :
Download or read book Divertor Particle Exhaust and Wall Inventory on DIII-D. written by and published by . This book was released on 1995 with total page 4 pages. Available in PDF, EPUB and Kindle. Book excerpt: Many tokamaks achieve optimum plasma performance by achieving low recycling; various wall conditioning techniques including helium glow discharge cleaning (HeGDC) are routinely applied to help achieve low recycling. Many of these techniques allow strong, transient wall pumping, but they may not be effective for long-pulse tokamaks, such as the International Thermonuclear Experimental Reactor (ITER), the Tokamak Physics Experiment (TPX), Tore Supra Continu, and JT-60SU. Continuous particle exhaust using an in-situ pumping scheme may be effective for wall inventory control in such devices. Recent particle balance experiments on the Tore Supra and DIII-D tokamaks demonstrated that the wall particle inventory could be reduced during a given discharge by use of continuous particle exhaust. In this paper we report the first results of wall inventory control and good performance with the in-situ DIII-D cryopump, replacing the HeGDC normally applied between discharges.
Book Synopsis Scientific and Technical Aerospace Reports by :
Download or read book Scientific and Technical Aerospace Reports written by and published by . This book was released on 1995 with total page 610 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.
Book Synopsis Results from the DIII-D Scientific Research Program by :
Download or read book Results from the DIII-D Scientific Research Program written by and published by . This book was released on 2001 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: The DIII-D research program is aimed at developing the scientific basis for advanced modes of operation which can enhance the commercial attractiveness of the tokamak as an energy producing system. Features that improve the attractiveness of the tokamak as a fusion power plant include: high power density (which demands high[beta]), high ignition margin (high energy confinement time), and steady state operation with low recirculating power (high bootstrap fraction), as well as adequate divertor heat removal, particle and impurity control. This set of requirements emphasizes that the approach to improved performance must be an integrated approach, optimizing the plasma from the core, through the plasma edge and into the divertor. The authors have produced high performance ELMing H-mode plasmas with[beta][sub N] H[sub 98y][approximately] 6 for 5[tau][sub E] ([approximately]1 s) and demonstrated that core transport barriers can be sustained for the length of the 5-s neutral beam pulse in L-mode plasmas. They have demonstrated off-axis electron cyclotron current drive for the first time in a tokamak, discovering an efficiency above theoretical expectations. Edge stability studies have shown that the H-mode edge pressure gradient is not limited by ballooning modes; the self-consistent bootstrap provides second stable regime access. Divertor experiments have provided a new understanding of convection and recombination in radiative divertors and have produced enhanced divertor radiation with scrape off layer plasma flows and impurity enrichment.
Download or read book دليل الوالدين الى تنمية الطفل written by and published by . This book was released on 1991 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:
Book Synopsis Variation of Particle Control with Changes in Divertor Geometry by :
Download or read book Variation of Particle Control with Changes in Divertor Geometry written by and published by . This book was released on 2004 with total page 11 pages. Available in PDF, EPUB and Kindle. Book excerpt: Recent experiments on DIII-D point to the importance of two factors in determining how effectively the deuterium particle inventory in a tokamak plasma can be controlled through pumping at the divertor target(s): (1) the divertor magnetic balance, i.e., the degree to which the divertor topology is single-null (SN) or double-null (DN), and (2) the direction of the of Bx{divergent}B ion drift with respect to the X-point(s). Changes in divertor magnetic balance near the DN shape have a much stronger effect on the particle exhaust rate at the inner divertor target(s) than on the particle exhaust rate at the outer divertor target(s). The particle exhaust rate for the DN shape is strongest at the outer strike point opposite the Bx{divergent}B ion particle drift direction. Our data suggests that the presence of Bx{divergent}B and ExB ion particle drifts in the scrapeoff layer (SOL) and divertors play an important role in the particle exhaust rates of DN and near-DN plasmas. Particle exhaust rates are shown to depend strongly on the edge (pedestal) density n{sub e, PED}. In the lower range of densities considered in this study, i.e., n{sub e, PED}/ n{sub GREENWALD}
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:
Author :United States. Congress. House. Committee on Appropriations. Subcommittee on Energy and Water Development Publisher : ISBN 13 : Total Pages :1364 pages Book Rating :4.3/5 (121 download)
Book Synopsis Energy and Water Development Appropriations for 2010: Dept. of Energy fiscal year 2010 justifications by : United States. Congress. House. Committee on Appropriations. Subcommittee on Energy and Water Development
Download or read book Energy and Water Development Appropriations for 2010: Dept. of Energy fiscal year 2010 justifications written by United States. Congress. House. Committee on Appropriations. Subcommittee on Energy and Water Development and published by . This book was released on 2009 with total page 1364 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Euro Abstracts written by and published by . This book was released on 1995 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:
Book Synopsis Plasma Surface Interactions in Controlled Fusion Devices by :
Download or read book Plasma Surface Interactions in Controlled Fusion Devices written by and published by . This book was released on 1978 with total page 658 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Book Synopsis Experiments on Steady State Particle Control in Tore Supra and DIII-D. by :
Download or read book Experiments on Steady State Particle Control in Tore Supra and DIII-D. written by and published by . This book was released on 1994 with total page 38 pages. Available in PDF, EPUB and Kindle. Book excerpt: Particle control is playing an increasingly important role in tokamak plasma performance. The present paper discusses particle control of hydrogen/deuterium by wall pumping on graphite or carbonized surfaces, as well as by external exhaust with pumped limiters and pumped divertors. Wall pumping is ultimately a transient effect and by itself not suitable for steady state particle exhaust. Therefore, external exhaust techniques with pumped divertors and limiters are being developed. How wall pumping phenomena interact and correlate with these inherently steady state, external exhaust techniques, is not well known to date. In the present paper, the processes involved in wall pumping and in external pumping are investigated in an attempt to evaluate the effect of external exhaust on wall pumping. Some of the key elements of this analysis are: (1) charge-exchange fluxes to the wall play a crucial role in the core-wall particle dynamics, (2) the recycling fluxes of thermal molecules have a high probability of ionization in the scrape-off layer, (3) thermal particles originating from the wall, which are ionized within the scrape-off layer, can be directly exhausted, thus providing a direct path between wall and exhaust which can be used to control the wall inventory. This way, the wall can be kept in a continuous pumping state in the sense that it continuously absorbs energetic particles and releases thermal molecules which are then removed by the external exhaust mechanism. While most of the ingredients of this analysis have been observed individually before, the present evaluation is an attempt to correlate effects of wall recycling and external exhaust.
