Download or read book A Snowflake Divertor and Its Properties written by and published by . This book was released on 2007 with total page 6 pages. Available in PDF, EPUB and Kindle. Book excerpt: Handling the power and particle exhaust in fusion reactors based on tokamaks is a challenging problem [1,2]. To bring the energy flux to the divertor plates to an acceptable level (

Download or read book Local Properties of the Magnetic Field in a Snowflake Divertor written by and published by . This book was released on 2010 with total page 17 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Erratum written by and published by . This book was released on 2008 with total page 3 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book The Snowflake Divertor written by and published by . This book was released on 2015 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: The snowflake magnetic configuration is characterized by the presence of two closely spaced poloidal field nulls that create a characteristic hexagonal (reminiscent of a snowflake) separatrix structure. The magnetic field properties and the plasma behaviour in the snowflake are determined by the simultaneous action of both nulls, this generating a lot of interesting physics, as well as providing a chance for improving divertor performance. One of the most interesting effects of the snowflake geometry is the heat flux sharing between multiple divertor channels. The authors summarise experimental results obtained with the snowflake configuration on several tokamaks. Wherever possible, relation to the existing theoretical models is described. Divertor concepts utilizing the properties of a snowflake configuration are briefly discussed.

Download or read book Boundary Plasma Physics written by Fulvio Militello and published by Springer Nature. This book was released on 2022-12-06 with total page 534 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book serves as an introduction to boundary plasma physics, providing an accessible entry point to the topic of plasma exhaust in magnetic confinement devices. While it delivers a concise, rigorous, and comprehensive account of all the major scientific topics relevant to those working on the subject, it also remains accessible and easy to consult due to its modular and compact structure. Beginning with the basic kinetic and fluid descriptions of plasma, and advancing through plasma-surface interactions, filamentary transport and plasma detachment, to conclude with a discussion of divertor configurations, this book represents a necessary and timely addition to the literature on the fast-growing field of boundary plasma physics. It will appeal to experienced theoreticians or experimentalists looking to enter the field as well as graduate students wishing to learn about it.

Download or read book Geometrical Properties of a Snow Flake Divertor written by and published by . This book was released on 2007 with total page 12 pages. Available in PDF, EPUB and Kindle. Book excerpt: Using a simple set of poloidal field coils, one can reach the situation where the null of the poloidal magnetic field in the divertor region is of a second order, not of the first order as in the usual X-point divertor. Then, the separatrix in the vicinity of the null-point splits the poloidal plane not into four sectors, but into six sectors, making the whole structure looking like a snow-flake (whence a name, [1]). This arrangement allows one to spread the heat load over much broader area than in the case of a standard divertor. A disadvantage of this configuration is in that it is topologically unstable, and, with the current in the plasma varying with time, it would switch either to the standard X-point mode, or to the mode with two X-points close to each other. To avoid this problem, it is suggested to have a current in the divertor coils by roughly 5% higher than in an 'optimum' regime (the one where a snow-flake separatrix is formed). In this mode, the configuration becomes stable and can be controlled by varying the current in the divertor coils in concert with the plasma current; on the other hand, a strong flaring of the scrape-off layer still remains in force. Geometrical properties of this configurations are analyzed for a simple model. Potential advantages and disadvantages of this scheme are discussed.

Download or read book Sawtooth Generated Magnetic Islands and the Properties of the Snowflake Divertor written by Gustavo Paganini Canal and published by . This book was released on 2014 with total page 183 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book The Magnetic Field Structure of a Snowflake Divertor written by and published by . This book was released on 2008 with total page 35 pages. Available in PDF, EPUB and Kindle. Book excerpt: The snowflake divertor exploits a tokamak geometry in which the poloidal magnetic field null approaches second order; the name stems from the characteristic hexagonal, snowflake-like, shape of the separatrix for an exact second-order null. The proximity of the poloidal field structure to that of a second-order null substantially modifies edge magnetic properties compared to the standard X-point geometry; this, in turn, affects the edge plasma behavior. Modifications include: (1) The flux expansion near the null-point becomes 2-3 times larger; (2) The connection length between the equatorial plane and divertor plate significantly increases; (3) Magnetic shear just inside the separatrix becomes much larger; and (4) In the open-field-line region, the squeezing of the flux-tubes near the null-point increases, thereby causing stronger decoupling of the plasma turbulence in the divertor legs and in the main SOL. These effects can be used to reduce the power load on the divertor plates and/or to suppress the 'bursty' component of the heat flux. It is emphasized that the snowflake divertor can be created by a relatively simple set of poloidal field coils situated beyond the toroidal field coils. Analysis of the robustness of the proposed divertor configuration with respect to changes of the plasma current distribution is presented and it is concluded that, even if the null is close to the second order, the configuration is quite robust.

Download or read book A Snowflake Divertor written by and published by . This book was released on 2008 with total page 11 pages. Available in PDF, EPUB and Kindle. Book excerpt: Handling high power loads on plasma facing components is one of the critical issues in developing an economically competitive fusion reactor based on tokamak. In this study, we provide a detailed analysis of a relatively unexplored approach to this problem based on the use of divertors with the poloidal magnetic field structure closely approaching a second-order null. We demonstrate that this geometry opens up new possibilities for radiative divertors, has favorable effect on the convective transport, and provides an additional control over ELM activity. In the ideal case where the null is exactly second order, the separatrix near the null acquires a characteristic hexagonal shape reminiscent of a snowflake, whence the name of this configuration. It can be created by a simple set of divertor coils situated outside the toroidal field coils.

Download or read book Snowflake Divertor Configuration Studies for NSTX Upgrade written by and published by . This book was released on 2011 with total page 26 pages. Available in PDF, EPUB and Kindle. Book excerpt: Snowflake divertor experiments in NSTX provide basis for PMI development toward NSTX-Upgrade. Snowflake configuration formation was followed by radiative detachment. Significant reduction of steady-state divertor heat flux observed in snowflake divertor. Impulsive heat loads due to Type I ELMs are partially mitigated in snowflake divertor. Magnetic control of snowflake divertor configuration is being developed. Plasma material interface development is critical for NSTX-U success. Four divertor coils should enable flexibility in boundary shaping and control in NSTX-U. Snowflake divertor experiments in NSTX provide good basis for PMI development in NSTX-Upgrade. FY 2009-2010 snowflake divertor experiments in NSTX: (1) Helped understand control of magnetic properties; (2) Core H-mode confinement unchanged; (3) Core and edge carbon concentration reduced; and (4) Divertor heat flux significantly reduced - (a) Steady-state reduction due to geometry and radiative detachment, (b) Encouraging results for transient heat flux handling, (c) Combined with impurity-seeded radiative divertor. Outlook for snowflake divertor in NSTX-Upgrade: (1) 2D fluid modeling of snowflake divertor properties scaling - (a) Edge and divertor transport, radiation, detachment threshold, (b) Compatibility with cryo-pump and lithium conditioning; (2) Magnetic control development; and (3) PFC development - PFC alignment and PFC material choice.

Download or read book Taming the Plasma material Interface with the Snowflake Divertor written by and published by . This book was released on 2015 with total page 6 pages. Available in PDF, EPUB and Kindle. Book excerpt: Experiments in several tokamaks have provided increasing support for the snowflake configuration as a viable tokamak heat exhaust concept. This white paper summarizes the snowflake properties predicted theoretically and studied experimentally, and identifies outstanding issues to be resolved in existing and future facilities before the snowflake divertor can qualify for the reactor interface.

Download or read book Magnetic Configuration Flexibility of Snowflake Divertor for HL 2M Analysis of Snowflake Divertor Configurations for HL 2M written by and published by . This book was released on 2014 with total page 7 pages. Available in PDF, EPUB and Kindle. Book excerpt: HL-2M (Li, 2013 [1]) is a tokamak device that is under construction. Based on the magnetic coils design of HL-2M, four kinds of divertor configurations are calculated by CORSICA code (Pearlstein et al., 2001 [2]) with the same main plasma parameters, which are standard divertor, exact snowflake divertor, snowflake-plus divertor and snowflake-minus divertor configurations. The potential properties of these divertors are analyzed and presented in this paper: low poloidal field area around X-point, connection length from outside mid-plane to the primary X-point, target plate design and magnetic field shear. The results show that the snowflake configurations not only can reduce the heat load at divertor target plates, but also may improve the magneto-hydrodynamic stability by stronger magnetic shear at the edge. Furthermore, a new divertor configuration, named "tripod divertor", is designed by adjusting the positions of the two X-points according to plasma parameters and magnetic coils current of HL-2M.

Download or read book Snowflake Divertor Studies in DIII D and NSTX Aimed at the Power Exhaust Solution for the Tokamak written by and published by . This book was released on 2013 with total page 6 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Magnetic Stochasticity in Magnetically Confined Fusion Plasmas written by Sadrilla Abdullaev and published by Springer Science & Business Media. This book was released on 2013-11-19 with total page 422 pages. Available in PDF, EPUB and Kindle. Book excerpt: This is the first book to systematically consider the modern aspects of chaotic dynamics of magnetic field lines and charged particles in magnetically confined fusion plasmas. The analytical models describing the generic features of equilibrium magnetic fields and magnetic perturbations in modern fusion devices are presented. It describes mathematical and physical aspects of onset of chaos, generic properties of the structure of stochastic magnetic fields, transport of charged particles in tokamaks induced by magnetic perturbations, new aspects of particle turbulent transport, etc. The presentation is based on the classical and new unique mathematical tools of Hamiltonian dynamics, like the action--angle formalism, classical perturbation theory, canonical transformations of variables, symplectic mappings, the Poincaré-Melnikov integrals. They are extensively used for analytical studies as well as for numerical simulations of magnetic field lines, particle dynamics, their spatial structures and statistical properties. The numerous references to articles on the latest development in the area are provided. The book is intended for graduate students and researchers who interested in the modern problems of magnetic stochasticity in magnetically confined fusion plasmas. It is also useful for physicists and mathematicians interested in new methods of Hamiltonian dynamics and their applications.

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 Issues in Nuclear High Energy Plasma Particle and Condensed Matter Physics 2011 Edition written by and published by ScholarlyEditions. This book was released on 2012-01-09 with total page 2502 pages. Available in PDF, EPUB and Kindle. Book excerpt: Issues in Nuclear, High Energy, Plasma, Particle, and Condensed Matter Physics: 2011 Edition is a ScholarlyEditions™ eBook that delivers timely, authoritative, and comprehensive information about Nuclear, High Energy, Plasma, Particle, and Condensed Matter Physics. The editors have built Issues in Nuclear, High Energy, Plasma, Particle, and Condensed Matter Physics: 2011 Edition on the vast information databases of ScholarlyNews.™ You can expect the information about Nuclear, High Energy, Plasma, Particle, and Condensed Matter Physics in this eBook 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: 2011 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 The quantification of the key physics parameters for the DEMO fusion power reactor and analysis of the reactor relevant physics issues written by Igitkhanov, Yu. and published by KIT Scientific Publishing. This book was released on 2015-01-20 with total page 150 pages. Available in PDF, EPUB and Kindle. Book excerpt: