WorldWideScience

Sample records for promising fusion plasma

  1. Fusion plasma physics

    CERN Document Server

    Stacey, Weston M

    2012-01-01

    This revised and enlarged second edition of the popular textbook and reference contains comprehensive treatments of both the established foundations of magnetic fusion plasma physics and of the newly developing areas of active research. It concludes with a look ahead to fusion power reactors of the future. The well-established topics of fusion plasma physics -- basic plasma phenomena, Coulomb scattering, drifts of charged particles in magnetic and electric fields, plasma confinement by magnetic fields, kinetic and fluid collective plasma theories, plasma equilibria and flux surface geometry, plasma waves and instabilities, classical and neoclassical transport, plasma-materials interactions, radiation, etc. -- are fully developed from first principles through to the computational models employed in modern plasma physics. The new and emerging topics of fusion plasma physics research -- fluctuation-driven plasma transport and gyrokinetic/gyrofluid computational methodology, the physics of the divertor, neutral ...

  2. Bridge between fusion plasma and plasma processing

    International Nuclear Information System (INIS)

    Ohno, Noriyasu; Takamura, Shuichi

    2008-01-01

    In the present review, relationship between fusion plasma and processing plasma is discussed. From boundary-plasma studies in fusion devices new applications such as high-density plasma sources, erosion of graphite in a hydrogen plasma, formation of helium bubbles in high-melting-point metals and the use of toroidal plasmas for plasma processing are emerging. The authors would like to discuss a possibility of knowledge transfer from fusion plasmas to processing plasmas. (T. Ikehata)

  3. Plasma nuclear fusion method

    International Nuclear Information System (INIS)

    Yamazaki, Shunpei; Miyanaga, Shoji; Wakaizumi, Kazuhiro; Takemura, Yasuhiko.

    1990-01-01

    Nuclear fusion reactions are attained by plasma gas phase reactions using magnetic fields and microwaves, and the degree of the reactions is controlled. That is, deuterium (D 2 ) is introduced into a plasma container by utilizing the resonance of microwaves capable of generating plasmas at high density higher by more than 10 - 10 3 times as compared with the high frequency and magnetic fields, and an electric energy is applied to convert gaseous D 2 into plasmas and nuclear fusion is conducted. Further, the deuterium ions in the plasmas are attracted to a surface of a material causing nuclear fusion under a negatively biased electric field from the outside (typically represented by Pd or Ti). Then, deuterium nuclei (d) or deuterium ions collide to the surface of the cathode on the side of palladium to conduct nuclear reaction at the surface or the inside (vicinity) thereof. However, a DC bias is applied as an external bias with the side of the palladium being negative. The cold nuclear fusion was demonstrated by placing a neutron counter in the vicinity of the container and confirming neutrons generated there. (I.S.)

  4. Controlled fusion and plasma physics

    International Nuclear Information System (INIS)

    1995-01-01

    This document presents the several speeches that took place during the 22nd European Physical Society conference on Controlled Fusion and Plasma Physics in Bournemouth, UK, between the 2nd and 7th July 1995. The talks deal with new experiments carried out on several tokamaks, particularly Tore Supra, concerning plasma confinement and fusion. Some information on specific fusion devices or tokamak devices is provided, as well as results of experiments concerning plasma instability. Separate abstracts were prepared for all the 31 papers in this volume. (TEC)

  5. Controlled fusion and plasma physics

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1996-12-31

    This document presents the several speeches that took place during the 22nd European Physical Society conference on Controlled Fusion and Plasma Physics in Bournemouth, UK, between the 2nd and 7th July 1995. The talks deal with new experiments carried out on several tokamaks, particularly Tore Supra, concerning plasma confinement and fusion. Some information on specific fusion devices or tokamak devices is provided, as well as results of experiments concerning plasma instability. Separate abstracts were prepared for all the 31 papers in this volume. (TEC).

  6. Controlled fusion and plasma physics

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1995-12-31

    This document presents the several speeches that took place during the 22nd European Physical Society conference on Controlled Fusion and Plasma Physics in Bournemouth, UK, between the 2nd and 7th July 1995. The talks deal with new experiments carried out on several tokamaks, particularly Tore Supra, concerning plasma confinement and fusion. Some information on specific fusion devices or tokamak devices is provided, as well as results of experiments concerning plasma instability. Separate abstracts were prepared for all the 31 papers in this volume. (TEC).

  7. Plasma physics and fusion plasma electrodynamics

    CERN Document Server

    Bers, Abraham

    2016-01-01

    Plasma is a ubiquitous state of matter at high temperatures. The electrodynamics of plasmas encompasses a large number of applications, from understanding plasmas in space and the stars, to their use in processing semiconductors, and their role in controlled energy generation by nuclear fusion. This book covers collective and single particle dynamics of plasmas for fully ionized as well as partially ionized plasmas. Many aspects of plasma physics in current fusion energy generation research are addressed both in magnetic and inertial confinement plasmas. Linear and nonlinear dynamics in hydrodynamic and kinetic descriptions are offered, making both simple and complex aspects of the subject available in nearly every chapter. The approach of dividing the basic aspects of plasma physics as "linear, hydrodynamic descriptions" to be covered first because they are "easier", and postponing the "nonlinear and kinetic descriptions" for later because they are "difficult" is abandoned in this book. For teaching purpose...

  8. TMX: a new fusion plasma experiment

    International Nuclear Information System (INIS)

    Anon.

    1977-01-01

    The primary goal of the magnetic fusion energy program at LLL is the development of a technically and economically feasible approach to the generation of fusion energy. Results from our earlier 2XIIB experiment lead us to believe that a fusion power plant based on a mirror system is technically feasible, assuming a favorable extrapolation to plasmas of reactor size. Achieving economic feasibility is more difficult. For power-producing applications, a reactor needs a large Q, the ratio of fusion power output to the power injected to sustain the system. In a conventional mirror reactor, the fusion power is only about equal to the power injected by the neutral beams--that is, Q is only about unity. A new idea, the tandem mirror concept described in this article, promises to increase this gain, enhancing Q by at least a factor of 5

  9. Controlled fusion and plasma heating

    International Nuclear Information System (INIS)

    1990-06-01

    The contributions presented in the 17th European Conference on Controlled Fusion and Plasma Heating were focused on Tore Supra investigations. The following subjects were presented: ohmic discharges, lower hybrid experiments, runaway electrons, Thomson scattering, plasma density measurements, magnetic fluctuations, polarization scattering, plasma currents, plasma fluctuation measurements, evaporation of hydrogen pellets in presence of fast electrons, ripple induced stochastic diffusion of trapped particles, tearing mode stabilization, edge effects on turbulence behavior, electron cyclotron heating, micro-tearing modes, divertors, limiters

  10. Fusion Plasma Theory project summaries

    Energy Technology Data Exchange (ETDEWEB)

    1993-10-01

    This Project Summary book is a published compilation consisting of short descriptions of each project supported by the Fusion Plasma Theory and Computing Group of the Advanced Physics and Technology Division of the Department of Energy, Office of Fusion Energy. The summaries contained in this volume were written by the individual contractors with minimal editing by the Office of Fusion Energy. Previous summaries were published in February of 1982 and December of 1987. The Plasma Theory program is responsible for the development of concepts and models that describe and predict the behavior of a magnetically confined plasma. Emphasis is given to the modelling and understanding of the processes controlling transport of energy and particles in a toroidal plasma and supporting the design of the International Thermonuclear Experimental Reactor (ITER). A tokamak transport initiative was begun in 1989 to improve understanding of how energy and particles are lost from the plasma by mechanisms that transport them across field lines. The Plasma Theory program has actively-participated in this initiative. Recently, increased attention has been given to issues of importance to the proposed Tokamak Physics Experiment (TPX). Particular attention has been paid to containment and thermalization of fast alpha particles produced in a burning fusion plasma as well as control of sawteeth, current drive, impurity control, and design of improved auxiliary heating. In addition, general models of plasma behavior are developed from physics features common to different confinement geometries. This work uses both analytical and numerical techniques. The Fusion Theory program supports research projects at US government laboratories, universities and industrial contractors. Its support of theoretical work at universities contributes to the office of Fusion Energy mission of training scientific manpower for the US Fusion Energy Program.

  11. Fusion Plasma Theory project summaries

    International Nuclear Information System (INIS)

    1993-10-01

    This Project Summary book is a published compilation consisting of short descriptions of each project supported by the Fusion Plasma Theory and Computing Group of the Advanced Physics and Technology Division of the Department of Energy, Office of Fusion Energy. The summaries contained in this volume were written by the individual contractors with minimal editing by the Office of Fusion Energy. Previous summaries were published in February of 1982 and December of 1987. The Plasma Theory program is responsible for the development of concepts and models that describe and predict the behavior of a magnetically confined plasma. Emphasis is given to the modelling and understanding of the processes controlling transport of energy and particles in a toroidal plasma and supporting the design of the International Thermonuclear Experimental Reactor (ITER). A tokamak transport initiative was begun in 1989 to improve understanding of how energy and particles are lost from the plasma by mechanisms that transport them across field lines. The Plasma Theory program has actively-participated in this initiative. Recently, increased attention has been given to issues of importance to the proposed Tokamak Physics Experiment (TPX). Particular attention has been paid to containment and thermalization of fast alpha particles produced in a burning fusion plasma as well as control of sawteeth, current drive, impurity control, and design of improved auxiliary heating. In addition, general models of plasma behavior are developed from physics features common to different confinement geometries. This work uses both analytical and numerical techniques. The Fusion Theory program supports research projects at US government laboratories, universities and industrial contractors. Its support of theoretical work at universities contributes to the office of Fusion Energy mission of training scientific manpower for the US Fusion Energy Program

  12. Fusion plasma theory project summaries

    Science.gov (United States)

    1993-10-01

    This Project Summary book is a published compilation consisting of short descriptions of each project supported by the Fusion Plasma Theory and Computing Group of the Advanced Physics and Technology Division of the Department of Energy, Office of Fusion Energy. The summaries contained in this volume were written by the individual contractors with minimal editing by the Office of Fusion Energy. Previous summaries were published in February of 1982 and December of 1987. The Plasma Theory program is responsible for the development of concepts and models that describe and predict the behavior of a magnetically confined plasma. Emphasis is given to the modelling and understanding of the processes controlling transport of energy and particles in a toroidal plasma and supporting the design of the International Thermonuclear Experimental Reactor (ITER). A tokamak transport initiative was begun in 1989 to improve understanding of how energy and particles are lost from the plasma by mechanisms that transport them across field lines. The Plasma Theory program has actively participated in this initiative. Recently, increased attention has been given to issues of importance to the proposed Tokamak Physics Experiment (TPX). Particular attention has been paid to containment and thermalization of fast alpha particles produced in a burning fusion plasma as well as control of sawteeth, current drive, impurity control, and design of improved auxiliary heating. In addition, general models of plasma behavior are developed from physics features common to different confinement geometries. This work uses both analytical and numerical techniques. The Fusion Theory program supports research projects at U.S. government laboratories, universities and industrial contractors. Its support of theoretical work at universities contributes to the office of Fusion Energy mission of training scientific manpower for the U.S. Fusion Energy Program.

  13. Plasma physics for controlled fusion

    CERN Document Server

    Miyamoto, Kenro

    2016-01-01

    This new edition presents the essential theoretical and analytical methods needed to understand the recent fusion research of tokamak and alternate approaches. The author describes magnetohydrodynamic and kinetic theories of cold and hot plasmas in detail. The book covers new important topics for fusion studies such as plasma transport by drift turbulence, which depend on the magnetic configuration and zonal flows. These are universal phenomena of microturbulence. They can modify the onset criterion for turbulent transport, instabilities driven by energetic particles as well as alpha particle generation and typical plasma models for computer simulation. The fusion research of tokamaks with various new versions of H modes are explained. The design concept of ITER, the international tokamak experimental reactor, is described for inductively driven operations as well as steady-state operations using non-inductive drives. Alternative approaches of reversed-field pinch and its relaxation process, stellator includi...

  14. Fusion Plasma Theory: Task 1, Magnetic confinement Fusion Plasma Theory

    International Nuclear Information System (INIS)

    Callen, J.D.

    1993-01-01

    The research performed under this grant during the current year has concentrated on few tokamak plasma confinement issues: applications of our new Chapman-Enskog-like approach for developing hybrid fluid/kinetic descriptions of tokamak plasmas; multi-faceted studies as part of our development of a new interacting island paradigm for the tokamak equilibrium'' and transport; investigations of the resolution power of BES and ECE diagnostics for measuring core plasma fluctuations; and studies of net transport in the presence of fluctuating surfaces. Recent progress and publications in these areas, and in the management of the NERSC node and the fusion theory workstations are summarized briefly in this report

  15. Controlled fusion and plasma physics

    International Nuclear Information System (INIS)

    1994-07-01

    40 papers are presented at this 21. conference on controlled fusion and plasma physics (JET). Titles are: effects of sawtooth crashes on beams ions and fusion product tritons; beta limits in H-modes and VH-modes; impurity induced neutralization of MeV energy protons in JET plasmas; lost α particle diagnostic for high-yield D-T fusion plasmas; 15-MeV proton emission from ICRF-heated plasmas; pulse compression radar reflectometry for density measurements; gamma-ray emission profile measurements during ICRH discharges; the new JET phase ICRH array; simulation of triton burn-up; parametric dependencies of JET electron temperature profiles; detached divertor plasmas; excitation of global Alfven Eigenmodes by RF heating; mechanisms of toroidal rotation; effect of shear in the radial electric field on confinement; plasma transport properties at the L-H transition; numerical study of plasma detachment conditions in JET divertor plasmas; the SOL width and the MHD interchange instability; non linear magnetic reconnection in low collisionality plasmas; topology and slowing down of high energy ion orbits; sawtooth crashes at high beta; fusion performances and alpha heating in future JET D-T plasmas; a stable route to high-beta plasmas with non-monotonic q-profiles; theory of propagation of changes to confinement; spatial distribution of gamma emissivity and fast ions during ICRF heating; multi-camera soft X-ray diagnostic; radiation phenomena and particle fluxes in the X-event; local measurement of transport parameters for laser injected trace impurities; impurity transport of high performance discharges; negative snakes and negative shear; neural-network charge exchange analysis; ion temperature anisotropy in helium neutral beam fuelling; impurity line emission due to thermal charge exchange in edge plasmas; control of convection by fuelling and pumping; VH mode accessibility and global H-mode properties; ion cyclotron emission by spontaneous emission; LHCD/ICRH synergy

  16. EDITORIAL: Plasma Surface Interactions for Fusion

    Science.gov (United States)

    2006-05-01

    Because plasma-boundary physics encompasses some of the most important unresolved issues for both the International Thermonuclear Experimental Reactor (ITER) project and future fusion power reactors, there is a strong interest in the fusion community for better understanding and characterization of plasma wall interactions. Chemical and physical sputtering cause the erosion of the limiters/divertor plates and vacuum vessel walls (made of C, Be and W, for example) and degrade fusion performance by diluting the fusion fuel and excessively cooling the core, while carbon redeposition could produce long-term in-vessel tritium retention, degrading the superior thermo-mechanical properties of the carbon materials. Mixed plasma-facing materials are proposed, requiring optimization for different power and particle flux characteristics. Knowledge of material properties as well as characteristics of the plasma material interaction are prerequisites for such optimizations. Computational power will soon reach hundreds of teraflops, so that theoretical and plasma science expertise can be matched with new experimental capabilities in order to mount a strong response to these challenges. To begin to address such questions, a Workshop on New Directions for Advanced Computer Simulations and Experiments in Fusion-Related Plasma Surface Interactions for Fusion (PSIF) was held at the Oak Ridge National Laboratory from 21 to 23 March, 2005. The purpose of the workshop was to bring together researchers in fusion related plasma wall interactions in order to address these topics and to identify the most needed and promising directions for study, to exchange opinions on the present depth of knowledge of surface properties for the main fusion-related materials, e.g., C, Be and W, especially for sputtering, reflection, and deuterium (tritium) retention properties. The goal was to suggest the most important next steps needed for such basic computational and experimental work to be facilitated

  17. 1-MW klystron for fusion plasma heating

    International Nuclear Information System (INIS)

    Okamoto, Tadashi; Miyake, Setsuo; Ohno, Hiroaki

    1985-01-01

    A plasma test apparatus to bring about the critical plasma conditions for nuclear fusion is now under construction in Japan Atomic Energy Research Institute. Among various means of plasma heating, the most promising is the lower hybrid resonance heating (LHRF) in the 2-GHz region. Although it has so far requied 7 to 8 MW of microwave power for the plasma test apparatus, the new klystron, E3778, now constructed by Toshiba has the world's highest output power of 1 MW in the 2-GHz region. In addition to the excellent high-power operation for 10 seconds, the wide operating frequency range of 1.7 to 2.26 GHz by dint of sophisticated high-speed tuning mechanism, and the high durability to reflected power of up to 2.0 of VSWR are the high-lighted features of this klystron, which have never been achieved by conventional klystrons. (author)

  18. Plasma physics for controlled fusion

    International Nuclear Information System (INIS)

    Miyamoto, K.

    2010-01-01

    The primary objective of this lecture note is to present the theories and experiments of plasma physics for recent activities of controlled fusion research for graduate and senior undergraduate students. Chapters 1-6 describe the basic knowledge of plasma and magnetohydrodynamics (MHD). MHD instabilities limit the beta ratio (ratio of plasma pressure to magnetic pressure) of confined plasma. Chapters 7-9 provide the kinetic theory of hot plasma and discuss the wave heating and non-inductive current drive. The dispersion relation derived by the kinetic theory are used to discuss plasma waves and perturbed modes. Landau damping is the essential mechanism of plasma heating and the stabilization of perturbation. Landau inverse damping brings the amplification of waves and the destabilization of perturbed modes. Chapter 10 explains the plasma transport due to turbulence, which is the most important and challenging subject for plasma confinement. Theories and simulations including subject of zonal flow are introduced. Chapters 11, 12 and 13 describe the recent activities of tokamak including ITER as well as spherical tokamak, reversed field pinch (RFP) and stellarator including quasi-symmetric configurations. Emphasis has been given to tokamak research since it made the most remarkable progress and the construction phase of 'International Tokamak Experimental Reactor' called ITER has already started. (author)

  19. Turbulence measurements in fusion plasmas

    International Nuclear Information System (INIS)

    Conway, G D

    2008-01-01

    Turbulence measurements in magnetically confined toroidal plasmas have a long history and relevance due to the detrimental role of turbulence induced transport on particle, energy, impurity and momentum confinement. The turbulence-the microscopic random fluctuations in particle density, temperature, potential and magnetic field-is generally driven by radial gradients in the plasma density and temperature. The correlation between the turbulence properties and global confinement, via enhanced diffusion, convection and direct conduction, is now well documented. Theory, together with recent measurements, also indicates that non-linear interactions within the turbulence generate large scale zonal flows and geodesic oscillations, which can feed back onto the turbulence and equilibrium profiles creating a complex interdependence. An overview of the current status and understanding of plasma turbulence measurements in the closed flux surface region of magnetic confinement fusion devices is presented, highlighting some recent developments and outstanding problems.

  20. Developments in plasma physics and controlled fusion

    International Nuclear Information System (INIS)

    Thompson, W.B.

    1980-01-01

    Some developments in plasma physics over the past twenty years are considered from the theoretical physics standpoint under the headings; oscillations, waves and instabilities, plasma turbulence, basic kinetic theory, and developments in fusion. (UK)

  1. Achievement of solid-state plasma fusion ('Cold-Fusion')

    International Nuclear Information System (INIS)

    Arata, Yoshiaki; Zhang, Yue-Chang

    1995-01-01

    Using a 'QMS' (Quadrupole Mass Spectrometer), the authors detected a significantly large amount (10 20 -10 21 [cm -3 ]) of helium ( 2 4 He), which was concluded to have been produced by a deuterium nuclear reaction within a host solid. These results were found to be fully repeatable and supported the authors' proposition that solid state plasma fusion ('Cold Fusion') can be generated in energetic deuterium Strongly Coupled Plasma ('SC-plasma'). This fusion reaction is thought to be sustained by localized 'Latticequake' in a solid-state media with the deuterium density equivalent to that of the host solid. While exploring this basic proposition, the characteristic differences when compared with ultra high temperature-state plasma fusion ('Hot Fusion') are clarified. In general, the most essential reaction product in both types of the deuterium plasma fusion is considered to be helium, irrespective of the 'well-known and/or unknown reactions', which is stored within the solid-state medium in abundance as a 'Residual Product', but which generally can not enter into nor be released from host-solid at a room temperature. Even measuring instruments with relatively poor sensitivity should be able to easily detect such residual helium. An absence of residual helium means that no nuclear fusion reaction has occurred, whereas its presence provides crucial evidence that nuclear fusion has, in fact, occurred in the solid. (author)

  2. Plasma Physics An Introduction to Laboratory, Space, and Fusion Plasmas

    CERN Document Server

    Piel, Alexander

    2010-01-01

    Plasma Physics gives a comprehensive introduction to the basic processes in plasmas and demonstrates that the same fundamental concepts describe cold gas-discharge plasmas, space plasmas, and hot fusion plasmas. Starting from particle drifts in magnetic fields, the principles of magnetic confinement fusion are explained and compared with laser fusion. Collective processes are discussed in terms of plasma waves and instabilities. The concepts of plasma description by magnetohydrodynamics, kinetic theory, and particle simulation are stepwise introduced. Space charge effects in sheath regions, double layers and plasma diodes are given the necessary attention. The new fundamental mechanisms of dusty plasmas are explored and integrated into the framework of conventional plasmas. The book concludes with a brief introduction to plasma discharges. Written by an internationally renowned researcher in experimental plasma physics, the text keeps the mathematical apparatus simple and emphasizes the underlying concepts. T...

  3. Fusion plasma research and education in Japan

    International Nuclear Information System (INIS)

    Inoue, N.

    1995-01-01

    Japanese fusion plasma research and education is reviewed by focusing on the activities promoted by the Ministry of Education, Science, Culture, and Sports (MOE). University fusion research is pursued by the academic interest and student education. A hierarchical structure of budget and manpower arrangement is observed. The small research groups of universities play the role of recruiting young students into the fusion and plasma society. After graduating the master course, most students are engaged by industries

  4. Tomography of laser fusion plasmas

    International Nuclear Information System (INIS)

    Ceglio, N.M.

    1977-01-01

    Experimental programs exist in a number of laboratories throughout the world to test the feasibility of using powerful laser systems to drive the implosion of hydrogen isotope fuel to thermonuclear burn conditions. In a typical experiment multiple laser beams are focused onto a glass microshell (typically 50 μm to 200 μm diameter) filled with an equimolar D-T gas mixture. X-ray and particle emissions from the target provide important information about the hydrodynamic implosion of the glass shell and the associated compression and heating of the D-T fuel. Standard diagnostics for imaging such emissions are the grazing incidence reflection (GIR) x-ray microscope and the pinhole camera. Recently, a particular coded imaging technique, Zone Plate Coded Imaging (ZPCI), has been successfully used for x-ray and particle microscopy of laser fusion plasmas. ZPCI is highly attractive for investigating laser produced plasmas because it possesses a tomographic capability not shared by either the GIR or pinhole imaging techniques. This presentation provides a brief discussion of the tomographic potential of ZPCI. In addition, the first tomographic x-ray images (tomographic resolution approximately 74 μm) of a laser produced plasma are presented

  5. Plasma physics an introduction to laboratory, space, and fusion plasmas

    CERN Document Server

    Piel, Alexander

    2017-01-01

    The enlarged new edition of this textbook provides a comprehensive introduction to the basic processes in plasmas and demonstrates that the same fundamental concepts describe cold gas-discharge plasmas, space plasmas, and hot fusion plasmas. Starting from particle drifts in magnetic fields, the principles of magnetic confinement fusion are explained and compared with laser fusion. Collective processes are discussed in terms of plasma waves and instabilities. The concepts of plasma description by magnetohydrodynamics, kinetic theory, and particle simulation are stepwise introduced. Space charge effects in sheath regions, double layers and plasma diodes are given the necessary attention. The novel fundamental mechanisms of dusty plasmas are explored and integrated into the framework of conventional plasmas. The book concludes with a concise description of modern plasma discharges. Written by an internationally renowned researcher in experimental plasma physics, the text keeps the mathematical apparatus simple a...

  6. Molecular Diagnostics of Fusion and Laboratory Plasmas

    Science.gov (United States)

    Fantz, U.

    2005-05-01

    The presence of molecules in the cold scrape-off layer of fusion experiments and industrial plasmas requires an understanding of the molecular dynamics in these low temperature plasmas. Suitable diagnostic methods can provide an insight in molecular processes in the plasma volume as well as for plasma surface interactions. A very simple but powerful technique is the molecular emission spectroscopy. Spectra are obtained easily, whereas interpretation might be very complex and relies on the availability of atomic and molecular data. Examples are given for hydrogen plasmas and plasmas with hydrocarbons which both are of importance in industrial applications as well as in fusion experiments.

  7. Molecular Diagnostics of Fusion and Laboratory Plasmas

    International Nuclear Information System (INIS)

    Fantz, U.

    2005-01-01

    The presence of molecules in the cold scrape-off layer of fusion experiments and industrial plasmas requires an understanding of the molecular dynamics in these low temperature plasmas. Suitable diagnostic methods can provide an insight in molecular processes in the plasma volume as well as for plasma surface interactions. A very simple but powerful technique is the molecular emission spectroscopy. Spectra are obtained easily, whereas interpretation might be very complex and relies on the availability of atomic and molecular data. Examples are given for hydrogen plasmas and plasmas with hydrocarbons which both are of importance in industrial applications as well as in fusion experiments

  8. Plasma physics and nuclear fusion research

    CERN Document Server

    Gill, Richard D

    1981-01-01

    Plasma Physics and Nuclear Fusion Research covers the theoretical and experimental aspects of plasma physics and nuclear fusion. The book starts by providing an overview and survey of plasma physics; the theory of the electrodynamics of deformable media and magnetohydrodynamics; and the particle orbit theory. The text also describes the plasma waves; the kinetic theory; the transport theory; and the MHD stability theory. Advanced theories such as microinstabilities, plasma turbulence, anomalous transport theory, and nonlinear laser plasma interaction theory are also considered. The book furthe

  9. Plasma physics and controlled nuclear fusion

    International Nuclear Information System (INIS)

    Sato, Tetsuya

    1993-05-01

    The report contains the proceedings of a conference on plasma physics. A fraction of topics included MHD instabilities, magnetic confinement and plasma heating in the field of fusion plasmas, in 8 papers falling in the INIS scope have been abstracted and indexed for the INIS database. (K.A.)

  10. Controlled fusion and plasma physics

    International Nuclear Information System (INIS)

    Bickerton, R.J.

    1991-01-01

    On JET results were presented on additional heating power, on a recently discovered regime of enhanced pellet performance (PEP), on low-density H-mode plasma confinement with hot ions, bounds on very high electric currents by material limiters, the first experiments on lower hybrid current drive, on the L-H transition threshold dependence on the direction of the gradient-B drift, and on alpha-particle physics issues. The TFTR presentations focused on transport. Particle loss ramifications of the toroidal Alfven eigenmodes were found to be small, while their threshold of excitation is lower than theoretically predicted. On DIII-D a scaling study of transport with gyroradius as the only variable was reported, with approximately Bohm scaling emerging; but the effective heat diffusivity scaling could not be established due to profile consistency effects. While beta-limit investigations with DIII-D generally confirm the ideal, MHD limit found by Troyon, evidence of a reduction of the accessible range for the internal inductance with the safety factor seems to favour current-density control in a steady-state D-T burner. Onset of strongly sheared poloidal rotation in a thin layer during the L-H mode transition was experimentally shown, while a new, so-called VH (''very high'') confinement mode was discovered by boronization of the wall. The JT-90 tokamak has recently been upgraded to JT-60-U. Presentations by the ASDEX team summarized the lack of agreement with theory of L-mode confinement. With TEXTOR, an improved mode (I-mode) of confinement was found by boronization. Finally, reviews are included on the status of impurity transport and helium removal in tokamaks, on stellarators, alternative magnetic confinement systems, inertial confinement, and non-fusion plasma physics. 2 tabs

  11. Atomic and molecular processes in fusion plasmas

    Energy Technology Data Exchange (ETDEWEB)

    Janev, R.K. [International Atomic Energy Agency, Vienna (Austria)

    1997-01-01

    The role of atomic and molecular processes in achieving and maintaining the conditions for thermonuclear burn in a magnetically confined fusion plasma is described. Emphasis is given to the energy balance and power and particle exhaust issues. The most important atomic and molecular processes which affect the radiation losses and impurity transport in the core plasma, the neutral particle transport in the plasma edge and the radiative cooling of divertor plasmas are discussed in greater detail. (author)

  12. Resistive Magnetohydrodynamics Simulation of Fusion Plasmas

    International Nuclear Information System (INIS)

    Tang, X.Z.; Fu, G.Y.; Jardin, S.C.; Lowe, L.L.; Park, W.; Strauss, H.R.

    2001-01-01

    Although high-temperature plasmas in laboratory magnetic fusion confinements are sufficiently collisionless that formal fluid closures are difficult to attain, the resistive MHD model has proven, by comparison with experimental data, to be useful for describing the large scale dynamics of magnetized plasmas. Resistive MHD model consists of Faraday's law for the evolution of the magnetic field and Navier-Stokes equation for the plasma flow. These equations are closed by the Ohm's law and an equation of state for the plasma

  13. Application of fusion plasma technology. Final report

    International Nuclear Information System (INIS)

    Sabri, Z.A.

    1976-06-01

    This report presents principal findings of studies conducted at Iowa State on Applications of Fusion Plasma Technology. Two tasks were considered. The first was to identify and investigate plasma processes for near term industrial applications of already developed plasma technology. The second was to explore the potential of reprocessing the fuel for fusion test facilities in a closed-cycle system. For the first task, two applications were considered. One was alumina reduction in magnetically confined plasmas, and the other was uranium enrichment using plasma centrifuges. For the second task, in-core and ex-core plasma purification were considered. Separation techniques that are compatible with the plasma state were identified and preliminary analysis of their effectiveness were carried out. The effects of differential ionization of impurities on the separation effectiveness are considered. Possible technical difficulties in both tasks are identified and recommendations for future work are given

  14. Far infrared fusion plasma diagnostics

    Energy Technology Data Exchange (ETDEWEB)

    Luhmann, N.C. Jr.; Peebles, W.A.

    1990-01-01

    Over the last several years, reflectometry has grown in importance as a diagnostic for both steady-state density Profiles as well as for the investigation of density fluctuations and turbulence. As a diagnostic for density profile measurement, it is generally believed to be well understood in the tokamak environment. However, its use as a fluctuation diagnostic is hampered by a lack of quantitative experimental understanding of its wavenumber sensitivity and spatial resolution. Several researchers, have theoretically investigated these questions. However, prior to the UCLA laboratory investigation, no group has experimentally investigated these questions. Because of the reflectometer's importance to the world effort in understanding plasma turbulence and transport, UCLA has, over the last year, made its primary Task IIIA effort the resolution of these questions. UCLA has taken the lead in a quantitative experimental understanding of reflectometer data as applied to the measurement of density fluctuations. In addition to this, work has proceeded on the design, construction, and installation of a reflectometer system on UCLA's CCT tokamak. This effort will allow a comparison between the improved confinement regimes (H-mode) observed on both the DIII-D and CCT machines with the goal of achieving a physics understanding of the phenomena. Preliminary investigation of a new diagnostic technique to measure density profiles as a function of time has been initiated at UCLA. The technique promises to be a valuable addition to the range of available plasma diagnostics. Work on advanced holographic reflectometry technique as applied to fluctuation diagnostics has awaited a better understanding of the reflectometer signal itself as discussed above. Efforts to ensure the transfer of the diagnostic developments have continued with particular attention devoted to the preliminary design of a multichannel FIR interferometer for MST.

  15. Dynamic behaviour of the high confinement mode of fusion plasmas

    International Nuclear Information System (INIS)

    Zohm, H.

    1995-05-01

    This paper describes the dynamic behaviour of the High Confinement mode (H-mode) of fusion plasmas, which is one of the most promising regimes of enhanced energy confinement in magnetic fusion research. The physics of the H-mode is not yet fully understood, and the detailed behaviour is complex. However, we establish a simple physics picture of the phenomenon. Although a first principles theory of the anomalous transport processes in a fusion plasma has not yet been given, we show that within the picture developed here, it is possible to describe the dynamic behaviour of the H-mode, namely the dynamics of the L-H transition and the occurrence of edge localized modes (ELMs). (orig.)

  16. Optical fibres for fusion plasma diagnostics systems

    International Nuclear Information System (INIS)

    Brichard, B.

    2005-01-01

    The condition to achieve and maintain the ignition of a thermonuclear fusion plasma ignition calls for the construction of a large scale fusion reactor, namely ITER. This reactor is designed to deliver an average fusion power of 500 MW. The burning of fusion plasma at such high power level will release a tremendous amount of energy in the form of particle fluxes and ionising radiation. This energy release, primarily absorbed by the plasma facing components, can significantly degrade the performances of the plasma diagnostic equipment surrounding the machine. To ensure a correct operation of the Tokamak we need to develop highly radiation-resistance devices. In plasma diagnostic systems, optical fibre is viewed as a convenient tool to transport light from the plasma edge to the diagnostic area. Radiation affects the optical performances of the fibre mainly by the occurrence of radiation-induced absorption and luminescence. Both effects degrade the light signal used for plasma diagnostic. SCK-CEN is currently assessing radiation-resistant glasses for optical fibres and is developing the associated qualification procedure. The main objectives of this study were to increase the lifetime of optical components in high radiation background and to develop a radiation resistance optical fibre capable to operate in the radiation background of ITER

  17. Plasma physics and controlled nuclear fusion research

    International Nuclear Information System (INIS)

    1980-01-01

    Full text: During the last decade, growing efforts have been devoted to studying the possible forms an electricity-producing thermonuclear reactor might take and the various technical problems that will have to be overcome. Previous IAEA Conferences took place in Salzburg (1961), Culham (1965), Novosibirsk (1968), Madison (1971), Tokyo (1974), Berchtesgaden (1976) and Innsbruck (1978) The exchange of information that has characterized this series of meetings is an important example of international co-operation and has contributed substantially to progress in controlled fusion research. The results of experiments in major research establishments, as well as the growing scientific insights in the field of plasma physics, give hope that the realization of nuclear fusion will be made possible on a larger scale and beyond the laboratory stage by the end of this century. The increase of the duration of existing tokamak discharges requires solution of the impurity control problem. First results from the new big machines equipped with the poloidal divertor recently came into operation. PDX (USA) and ASDEX (F.R. of Germany) show that various divertor configurations can be established and maintained and that the divertors function in the predicted manner. The reduction of high-Z impurities on these machines by a factor 10 was achieved. As a result of extensive research on radio-frequency (RF) plasma heating on tokamaks: PLT (USA), TFR (France), JFT-2 (Japan), the efficiency of this attractive method of plasma heating comparable to neutral beam heating was demonstrated. It was shown that the density of the input power of about 5-10 kW/cm 2 is achievable and this limit is high enough for application to reactor-like machines. One of the inspiring results reported at the conference was the achievement of value (the ratio of plasma pressure to magnetic field pressure) of ∼ 3% on tokamaks T-11 (USSR) and ISX-B (USA). It is important to note that this value exceeds the

  18. Microwave reflectometry for fusion plasma diagnostics

    International Nuclear Information System (INIS)

    1992-01-01

    This document contains a collection of 26 papers on ''Microwave Reflectometry for Fusion Plasma Diagnostics'', presented at the IAEA Technical Committee Meeting of the same name held at the JET Joint Undertaking, Abingdon, United Kingdom, March 4-6, 1992. It contains five papers on the measurement of plasma density profiles, six papers on theory and simulations in support of the development and application of this type of plasma diagnostics, eight papers on the measurement of density transients and fluctuations, and seven on new approaches to reflectometry-based plasma diagnostics. Refs, figs and tabs

  19. Plasma Surface interaction in Controlled fusion devices

    International Nuclear Information System (INIS)

    1990-05-01

    The subjects presented in the 9th conference on plasma surface interaction in controlled fusion devices were: the modifications of power scrape-off-length and power deposition during various configurations in Tore Supra plasmas; the effects observed in ergodic divertor experiments in Tore-Supra; the diffuse connexion induced by the ergodic divertor and the topology of the heat load patterns on the plasma facing components in Tore-Supra; the study of the influence of air exposure on graphite implanted by low energy high density deuterium plasma

  20. Fusion programs in Applied Plasma Physics

    International Nuclear Information System (INIS)

    1992-07-01

    The Applied Plasma Physics (APP) program at General Atomics (GA) described here includes four major elements: (a) Applied Plasma Physics Theory Program, (b) Alpha Particle Diagnostic, (c) Edge and Current Density Diagnostic, and (d) Fusion User Service Center (USC). The objective of the APP theoretical plasma physics research at GA is to support the DIII-D and other tokamak experiments and to significantly advance our ability to design a commercially-attractive fusion reactor. We categorize our efforts in three areas: magnetohydrodynamic (MHD) equilibria and stability; plasma transport with emphasis on H-mode, divertor, and boundary physics; and radio frequency (rf). The objective of the APP alpha particle diagnostic is to develop diagnostics of fast confined alpha particles using the interactions with the ablation cloud surrounding injected pellets and to develop diagnostic systems for reacting and ignited plasmas. The objective of the APP edge and current density diagnostic is to first develop a lithium beam diagnostic system for edge fluctuation studies on the Texas Experimental Tokamak (TEXT). The objective of the Fusion USC is to continue to provide maintenance and programming support to computer users in the GA fusion community. The detailed progress of each separate program covered in this report period is described in the following sections

  1. Mirror fusion test facility plasma diagnostics system

    International Nuclear Information System (INIS)

    Thomas, S.R. Jr.; Coffield, F.E.; Davis, G.E.; Felker, B.

    1979-01-01

    During the past 25 years, experiments with several magnetic mirror machines were performed as part of the Magnetic Fusion Energy (MFE) Program at LLL. The latest MFE experiment, the Mirror Fusion Test Facility (MFTF), builds on the advances of earlier machines in initiating, stabilizing, heating, and sustaining plasmas formed with deuterium. The goals of this machine are to increase ion and electron temperatures and show a corresponding increase in containment time, to test theoretical scaling laws of plasma instabilities with increased physical dimensions, and to sustain high-beta plasmas for times that are long compared to the energy containment time. This paper describes the diagnostic system being developed to characterize these plasma parameters

  2. Advanced fusion in ICRF injected plasmas

    International Nuclear Information System (INIS)

    Carpignano, F.; Coppi, B.; Detragiache, P.; Migliuolo, S.; Nassi, M.; Rogers, B.

    1994-01-01

    Fusion burning of a D- 3 He mixture in a high density, high magnetic field, compact toroidal experiment (Ignitor) with a high injected power density at the ion cyclotron frequency (ICRF) is investigated. A superthermal tail (with energies exceeding 1 MeV in the central part of the plasma column) is induced in the distribution of the minority 3 He population ( 0 20 m -3 ). This stems from the high value of the peak RF power density absorbed by the minority species (ρ RF ∼ 60 MW/m 3 ) that should be obtained in Ignitor when the total injected power is about 18 MW. This experiment is suitable to begin the study of advanced fusion burning, because of the high plasma currents (I p 3 He fusion powers of the order of 1 MW should be attained. (author) 8 refs., 3 figs

  3. Plasma surface interactions in controlled fusion devices

    International Nuclear Information System (INIS)

    Ghendrih, Ph.; Becoulet, M.; Costanzo, L.

    2000-07-01

    This report brings together all the contributions of EURATOM/CEA association to the 14. international conference on plasma surface interactions in controlled fusion devices. 24 papers are presented and they deal mainly with the ergodic divertor and the first wall of Tore-supra tokamak

  4. Plasma surface interactions in controlled fusion devices

    Energy Technology Data Exchange (ETDEWEB)

    Ghendrih, Ph.; Becoulet, M.; Costanzo, L. [and others

    2000-07-01

    This report brings together all the contributions of EURATOM/CEA association to the 14. international conference on plasma surface interactions in controlled fusion devices. 24 papers are presented and they deal mainly with the ergodic divertor and the first wall of Tore-supra tokamak.

  5. Fundamental studies of fusion plasmas

    International Nuclear Information System (INIS)

    Aamodt, R.E.; Catto, P.J.; D'Ippolito, D.A.; Myra, J.R; Russell, D.A.

    1991-01-01

    This report discusses: ICRF impurity studies; ICRF convective cells; sheath plasma waves and anomalous IBW loading; a quasilinear description for fast wave minority heating permitting off magnetic axis heating in a tokamak; and runaway electrons studies in support of TEXT

  6. Fundamental studies of fusion plasmas

    International Nuclear Information System (INIS)

    Aamodt, R.E.; Catto, P.J.; D'Ippolito, D.A.; Myra, J.R.; Russell, D.A.

    1993-01-01

    Work on ICRF interaction with the edge plasma is reported. ICRF generated convective cells have been established as an important mechanism for influencing edge transport and interaction with the H-mode, and for controlling profiles in the tokamak scrape-off-layer. Power dissipation by rf sheaths has been shown to be significant for some misaligned ICRF and IIBW antenna systems. Near-field antenna sheath work has been extended to the far-field case, important for experiments with low single pass absorption. Impurity modeling and Faraday screen design support has been provided for the ICRF community. In the area of core-ICRF physics, the kinetic theory of heating by applied ICRF waves has been extended to retain important geometrical effects relevant to modeling minority heated tokamak plasmas, thereby improving on the physics base that is standard in presently employed codes. Both the quasilinear theory of ion heating, and the plasma response function important in wave codes have been addressed. In separate studies, it has been shown that highly anisotropic minority heated plasmas can give rise to unstable field fluctuations in some situations. A completely separate series of studies have contributed to the understanding of tokamak confinement physics. Additionally, a diffraction formalism has been produced which will be used to access the focusability of lower hybrid, ECH, and gyrotron scattering antennas in dynamic plasma configurations

  7. Correlation measurements for fusion plasma diagnostics

    International Nuclear Information System (INIS)

    Pazsit, I.

    1995-01-01

    A list of a few methods for plasma diagnostics via fluctuations (noise) analysis of random (both temporally and spatially) system parameters is reviewed. Analogy is drawn with certain noise analysis methods, used in the diagnostics of fission reactors. These methods have been applied also to fusion measurements to some extent. However, the treatment of fusion plasma fluctuations is dominated by an approach that allows for temporal randomness, but assumes periodicity in space. This approach suits well a large class of phenomena such as magnetic fluctuations (MHD effects), but is much less suited to treat localised effects such as turbulence and density fluctuations. This paper discusses the potentials of the former approach, i.e. ordinary noise analysis methods of non-periodic variables in fusion plasma diagnostics. A new recommendation is to use the crossed beam correlation analysis of soft X-ray signals for determining the local short-range correlations in the plasma and to perform a systematic exploration of the plasma spatial correlation structure with that and other methods. 16 refs, 7 figs

  8. Fusion Plasma Physics and ITER - An Introduction (2/4)

    CERN Multimedia

    CERN. Geneva

    2011-01-01

    The second lecture will explore some of the key physics phenomena which govern the behaviour of magnetic fusion plasmas and which have been the subject of intense research during the past 50 years: plasma confinement, magnetohydrodynamic stability and plasma-wall interactions encompass the major areas of plasma physics which must be understood to assemble an overall description of fusion plasma behaviour. In addition, as fusion plasmas approach the “burning plasma” regime, where internal heating due to fusion products dominates other forms of heating, the physics of the interaction between the α-particles produced by D-T fusion reactions and the thermal “background” plasma becomes significant. This lecture will also introduce the basic physics of fusion plasma production, plasma heating and current drive, and plasma measurements (“diagnostics”).

  9. Fundamental studies of fusion plasmas

    International Nuclear Information System (INIS)

    Aamodt, R.E.; Catto, P.J.; D'Ippolito, D.A.; Myra, J.R.; Russell, D.A.

    1990-03-01

    This paper discusses tokamak transport, auxiliary heating physics; ICRF impurity study; ponderomotive stabilization studies; ICRF induced fluxes in the edge plasma; runaway electron confinement in TEXT; rf sheath modelling for ICRF antenna Faraday screens; and isotropic energetic in fluxes in tokamaks

  10. Plasma physics for controlled fusion. 2. ed.

    Energy Technology Data Exchange (ETDEWEB)

    Miyamoto, Kenro

    2016-08-01

    This new edition presents the essential theoretical and analytical methods needed to understand the recent fusion research of tokamak and alternate approaches. The author describes magnetohydrodynamic and kinetic theories of cold and hot plasmas in detail. The book covers new important topics for fusion studies such as plasma transport by drift turbulence, which depend on the magnetic configuration and zonal flows. These are universal phenomena of microturbulence. They can modify the onset criterion for turbulent transport, instabilities driven by energetic particles as well as alpha particle generation and typical plasma models for computer simulation. The fusion research of tokamaks with various new versions of H modes are explained. The design concept of ITER, the international tokamak experimental reactor, is described for inductively driven operations as well as steady-state operations using non-inductive drives. Alternative approaches of reversed-field pinch and its relaxation process, stellator including quasi-symmetric system, open-end system of tandem mirror and inertial confinement are also explained. Newly added and updated topics in this second edition include zonal flows, various versions of H modes, and steady-state operations of tokamak, the design concept of ITER, the relaxation process of RFP, quasi-symmetric stellator, and tandem mirror. The book addresses graduate students and researchers in the field of controlled fusion.

  11. Plasma physics for controlled fusion. 2. ed.

    International Nuclear Information System (INIS)

    Miyamoto, Kenro

    2016-01-01

    This new edition presents the essential theoretical and analytical methods needed to understand the recent fusion research of tokamak and alternate approaches. The author describes magnetohydrodynamic and kinetic theories of cold and hot plasmas in detail. The book covers new important topics for fusion studies such as plasma transport by drift turbulence, which depend on the magnetic configuration and zonal flows. These are universal phenomena of microturbulence. They can modify the onset criterion for turbulent transport, instabilities driven by energetic particles as well as alpha particle generation and typical plasma models for computer simulation. The fusion research of tokamaks with various new versions of H modes are explained. The design concept of ITER, the international tokamak experimental reactor, is described for inductively driven operations as well as steady-state operations using non-inductive drives. Alternative approaches of reversed-field pinch and its relaxation process, stellator including quasi-symmetric system, open-end system of tandem mirror and inertial confinement are also explained. Newly added and updated topics in this second edition include zonal flows, various versions of H modes, and steady-state operations of tokamak, the design concept of ITER, the relaxation process of RFP, quasi-symmetric stellator, and tandem mirror. The book addresses graduate students and researchers in the field of controlled fusion.

  12. Magnetized Target Fusion Driven by Plasma Liners

    Science.gov (United States)

    Thio, Y. C. Francis; Cassibry, Jason; Eskridge, Richard; Kirkpatrick, Ronald C.; Knapp, Charles E.; Lee, Michael; Martin, Adam; Smith, James; Wu, S. T.; Rodgers, Stephen L. (Technical Monitor)

    2001-01-01

    For practical applications of magnetized target fusion, standoff drivers to deliver the imploding momentum flux to the target plasma remotely are required. Quasi-spherically converging plasma jets have been proposed as standoff drivers for this purpose. The concept involves the dynamic formation of a quasi-spherical plasma liner by the merging of plasma jets, and the use of the liner so formed to compress a spheromak or a field reversed configuration (FRC). Theoretical analysis and computer modeling of the concept are presented. It is shown that, with the appropriate choice of the flow parameters in the liner and the target, the impact between the liner and the target plasma can be made to be shockless in the liner or to generate at most a very weak shock in the liner. Additional information is contained in the original extended abstract.

  13. BOOK REVIEW: Controlled Fusion and Plasma Physics

    Science.gov (United States)

    Engelmann, F.

    2007-07-01

    This new book by Kenro Miyamoto provides an up-to-date overview of the status of fusion research and the important parts of the underlying plasma physics at a moment where, due to the start of ITER construction, an important step in fusion research has been made and many new research workers will enter the field. For them, and also for interested graduate students and physicists in other fields, the book provides a good introduction into fusion physics as, on the whole, the presentation of the material is quite appropriate for getting acquainted with the field on the basis of just general knowledge in physics. There is overlap with Miyamoto's earlier book Plasma Physics for Nuclear Fusion (MIT Press, Cambridge, USA, 1989) but only in a few sections on subjects which have not evolved since. The presentation is subdivided into two parts of about equal length. The first part, following a concise survey of the physics basis of thermonuclear fusion and of plasmas in general, covers the various magnetic configurations studied for plasma confinement (tokamak; reversed field pinch; stellarator; mirror-type geometries) and introduces the specific properties of plasmas in these devices. Plasma confinement in tokamaks is treated in particular detail, in compliance with the importance of this field in fusion research. This includes a review of the ITER concept and of the rationale for the choice of ITER's parameters. In the second part, selected topics in fusion plasma physics (macroscopic instabilities; propagation of waves; kinetic effects such as energy transfer between waves and particles including microscopic instabilities as well as plasma heating and current drive; transport phenomena induced by turbulence) are presented systematically. While the emphasis is on displaying the essential physics, deeper theoretical analysis is also provided here. Every chapter is complemented by a few related problems, but only partial hints for their solution are given. A selection of

  14. Plasma simulation and fusion calculation

    International Nuclear Information System (INIS)

    Buzbee, B.L.

    1983-01-01

    Particle-in-cell (PIC) models are widely used in fusion studies associated with energy research. They are also used in certain fluid dynamical studies. Parallel computation is relevant to them because (1) PIC models are not amenable to a lot of vectorization - about 50% of the total computation can be vectorized in the average model; (2) the volume of data processed by PIC models typically necessitates use of secondary storage with an attendant requirements for high-speed I/O; and (3) PIC models exist today whose implementation requires a computer 10 to 100 times faster than the Cray-1. This paper discusses parallel formulation of PIC models for master/slave architectures and ring architectures. Because interprocessor communication can be a decisive factor in the overall efficiency of a parallel system, we show how to divide these models into large granules that can be executed in parallel with relatively little need for communication. We also report measurements of speedup obtained from experiments on the UNIVAC 1100/84 and the Denelcor HEP

  15. Heavy-ion fusion: future promise and future directions

    International Nuclear Information System (INIS)

    Dudziak, D.J.; Saylor, W.W.; Pendergrass, J.H.

    1986-01-01

    The previous papers in this heavy-ion fusion special session have described work performed as part of the Heavy-Ion Fusion Systems Assessment (HIFSA) Project. Key technical issues in the design and costing of targets, induction linacs, beam transport, reactor, balance of plant, and systems integration have been identified and described. The HIFSA systems model was used to measure the relative value of improvements in physics understanding and technology developments in many different areas. Within the limits of our 1986 knowledge and imagination, this study defines the most attractive heavy-ion fusion (HIF) power plant concepts. The project has deliberately avoided narrowing the focus to a point facility design; thus, the generic systems modeling capability developed in the process allows for relative comparisons among design options. We will describe what are thought to be achievable breakthroughs and what the relative significance of the breakthroughs will be, although the specific mechanism for achieving some breakthroughs may not be clear at this point. This degree of optimism concerning such breakthroughs is probably at least as conservative as that used in other fusion assessments

  16. X-ray spectroscopy from fusion plasmas

    International Nuclear Information System (INIS)

    Glenzer, S H.

    1998-01-01

    Our understanding of laser energy coupling into laser-driven inertial confinement fusion targets largely depends on our ability to accurately measure and simulate the plasma conditions in the underdense corona and in high density capsule implosions. X-ray spectroscopy is an important technique which has been applied to measure the total absorption of laser energy into the fusion target, the fraction of laser energy absorbed by hot electrons, and the conditions in the fusion capsule in terms of density and temperature. These parameters provide critical benchmarking data for performance studies of the fusion target and for radiation-hydrodynamic and laser-plasma interaction simulations. Using x-ray spectroscopic techniques for these tasks has required its application to non-standard conditions where kinetics models have not been extensively tested. In particular, for the conditions in high density implosions, where electron temperatures achieve 1 - 2 keV and electron densities reach 10 24 cm -3 evolving on time scales of 21 cm -3 and which am independently diagnosed with Thomson scattering and stimulated Raman scattering. We find that kinetics modeling is in good agreement with measured intensities of the dielectronic satellites of the He-β line (n= l-3) of Ar XVII. Applying these findings to the experimental results of capsule implosions provides additional evidence of temperature gradients at peak compression

  17. Fundamentals of plasma physics and controlled fusion

    Energy Technology Data Exchange (ETDEWEB)

    Miyamoto, Kenro

    2000-10-01

    The present lecture note was written to fill a gap between text books for undergraduates and specific review articles written by specialists for their young colleagues. The note may be divided in three parts. The first part is on basic characteristics of a plasma in a magnetic field. The second part describes plasma confinement and heating with an emphasis on magnetohydrodynamic instabilities. In addition, propagation of plasma waves, plasma heating by electromagnetic waves are given. The third part is devoted to various specific concepts of nuclear fusion. Emphases are placed on toroidal devices, especially on tokamak devices and stellarators. One might feel heavy mathematics glimpsing the present note, especially in the part treating magnetohydrodynamic instabilities. (author)

  18. Introduction to plasma physics and controlled fusion

    CERN Document Server

    Chen, Francis F

    1984-01-01

    This complete introduction to plasma physics and controlled fusion by one of the pioneering scientists in this expanding field offers both a simple and intuitive discussion of the basic concepts of this subject and an insight into the challenging problems of current research. In a wholly lucid manner the work covers single-particle motions, fluid equations for plasmas, wave motions, diffusion and resistivity, Landau damping, plasma instabilities and nonlinear problems. For students, this outstanding text offers a painless introduction to this important field; for teachers, a large collection of problems; and for researchers, a concise review of the fundamentals as well as original treatments of a number of topics never before explained so clearly. This revised edition contains new material on kinetic effects, including Bernstein waves and the plasma dispersion function, and on nonlinear wave equations and solitons.

  19. Atomic resonances in nuclear fusion plasmas

    International Nuclear Information System (INIS)

    Clauser, C. F.; Barrachina, R. O.

    2013-01-01

    We present a study of zero energy resonances of photoionization and radiative recombination cross section for the different species in a fusion reactor. In this context, the interaction potential is screened and its typical length depends on the plasma density and temperature. Due to the nature of these resonances, we propose other atomic processes in which they can take place. Finally, we show the density and temperature conditions where these resonances occur and their probable consequence on the reactor performance. (author)

  20. Massachusetts Institute of Technology, Plasma Fusion Center, Technical Research Programs

    International Nuclear Information System (INIS)

    1980-08-01

    A review is given of the technical programs carried out by the Plasma Fusion Center. The major divisions of work areas are applied plasma research, confinement experiments, fusion technology and engineering, and fusion systems. Some objectives and results of each program are described

  1. Massachusetts Institute of Technology, Plasma Fusion Center, Technical Research Programs

    Energy Technology Data Exchange (ETDEWEB)

    Davidson, Ronald C.

    1980-08-01

    A review is given of the technical programs carried out by the Plasma Fusion Center. The major divisions of work areas are applied plasma research, confinement experiments, fusion technology and engineering, and fusion systems. Some objectives and results of each program are described. (MOW)

  2. Plasma physics and controlled nuclear fusion research 1988. V.3

    International Nuclear Information System (INIS)

    1989-01-01

    Volume 3 of the proceedings of the twelfth international conference on plasma physics and controlled nuclear fusion, held in Nice, France, 12-19 October, 1988, contains papers presented on inertial fusion. Direct and indirect laser implosion experiments, programs of laser construction, computer modelling of implosions and resulting plasmas, and light ion beam fusion experiments are discussed. Refs, figs and tabs

  3. Heavy-ion fusion: Future promise and future directions

    International Nuclear Information System (INIS)

    Dudziak, D.J.; Saylor, W.W.; Pendergrass, J.H.

    1986-01-01

    The previous several papers in this heavy-ion fusion special session have described work that has taken place as part of the Heavy-Ion Fusion Systems Assessment (HIFSA) project. Key technical issues in the design and costing of targets, accelerator systems, beam transport, reactor and balance-of-plant, and systems integration have been identified and described. The HIFSA systems model was used to measure the relative value of improvements in physics understanding and technology developments in many different areas. The result of this study has been to, within the limits of our 1986 imagination and creativity, define the ''most attractive'' future heavy-ion fusion (HIF) power plant at some time in the future (beyond the year 2020 in this case). The project has specifically avoided narrowing the focus to a point facility design; thus, the generic systems modeling capability developed in the process allows for a relative comparison among design options. The authors describe what are thought to be achievable breakthroughs and what the relative significance of the breakthroughs will be, although the specific mechanism for achieving some breakthroughs may not be clear at this point

  4. Sawtooth control in fusion plasmas

    International Nuclear Information System (INIS)

    Graves, J P; Angioni, C; Budny, R V; Buttery, R J; Coda, S; Eriksson, L-G; Gimblett, C G; Goodman, T P; Hastie, R J; Henderson, M A; Koslowski, H R; Mantsinen, M J; Martynov, An; Mayoral, M-L; Mueck, A; Nave, M F F; Sauter, O; Westerhof, E

    2005-01-01

    Clear observations of early triggering of neo-classical tearing modes by sawteeth with long quiescent periods have motivated recent efforts to control, and in particular destabilize, sawteeth. One successful approach explored in TCV utilizes electron cyclotron heating in order to locally increase the current penetration time in the core. The latter is also achieved in various machines by depositing electron cyclotron current drive or ion cyclotron current drive close to the q = 1 rational surface. Crucially, localized current drive also succeeds in destabilizing sawteeth which are otherwise stabilized by a co-existing population of energetic trapped ions in the core. In addition, a recent reversed toroidal field campaign at JET demonstrates that counter-neutral beam injection (NBI) results in shorter sawtooth periods than in the Ohmic regime. The clear dependence of the sawtooth period on the NBI heating power and the direction of injection also manifests itself in terms of the toroidal plasma rotation, which consequently requires consideration in the theoretical interpretation of the experiments. Another feature of NBI, expected to be especially evident in the negative ion based neutral beam injection (NNBI) heating planned for ITER, is the parallel velocity asymmetry of the fast ion population. It is predicted that a finite orbit effect of asymmetrically distributed circulating ions could strongly modify sawtooth stability. Furthermore, NNBI driven current with non-monotonic profile could significantly slow down the evolution of the safety factor in the core, thereby delaying sawteeth

  5. Sawtooth control in fusion plasmas

    Science.gov (United States)

    Graves, J. P.; Angioni, C.; Budny, R. V.; Buttery, R. J.; Coda, S.; Eriksson, L.-G.; Gimblett, C. G.; Goodman, T. P.; Hastie, R. J.; Henderson, M. A.; Koslowski, H. R.; Mantsinen, M. J.; Martynov, An; Mayoral, M.-L.; Mück, A.; Nave, M. F. F.; Sauter, O.; Westerhof, E.; Contributors, JET–EFDA

    2005-12-01

    Clear observations of early triggering of neo-classical tearing modes by sawteeth with long quiescent periods have motivated recent efforts to control, and in particular destabilize, sawteeth. One successful approach explored in TCV utilizes electron cyclotron heating in order to locally increase the current penetration time in the core. The latter is also achieved in various machines by depositing electron cyclotron current drive or ion cyclotron current drive close to the q = 1 rational surface. Crucially, localized current drive also succeeds in destabilizing sawteeth which are otherwise stabilized by a co-existing population of energetic trapped ions in the core. In addition, a recent reversed toroidal field campaign at JET demonstrates that counter-neutral beam injection (NBI) results in shorter sawtooth periods than in the Ohmic regime. The clear dependence of the sawtooth period on the NBI heating power and the direction of injection also manifests itself in terms of the toroidal plasma rotation, which consequently requires consideration in the theoretical interpretation of the experiments. Another feature of NBI, expected to be especially evident in the negative ion based neutral beam injection (NNBI) heating planned for ITER, is the parallel velocity asymmetry of the fast ion population. It is predicted that a finite orbit effect of asymmetrically distributed circulating ions could strongly modify sawtooth stability. Furthermore, NNBI driven current with non-monotonic profile could significantly slow down the evolution of the safety factor in the core, thereby delaying sawteeth.

  6. Thermonuclear fusion plasma produced by lasers

    International Nuclear Information System (INIS)

    Yamanaka, C.; Yokoyama, M.; Nakai, S.; Sasaki, T.; Yoshida, K.; Matoba, M.; Yamabe, C.; Tschudi, T.; Yamanaka, T.; Mizui, J.; Yamaguchi, N.; Nishikawa, K.

    1975-01-01

    Recently, much attention has been focused on laser fusion schemes using high-density plasmas produced by implosion. Scientific-feasibility laser-fusion experiments are now in time. But the physics of interaction between laser and plasma, the high-compression technique and the development of high-power lasers are still important problems to be solved if laser fusion is to make some progress. In the field of laser-plasma coupling, experiments were carried out in which hydrogen and deuterium sticks were bombarded by laser beams; in these experiments, a glass-laser system, LETKKO-I, with an energy of 50 J in a nanosecond pulse, and a double-discharge TEA CO 2 laser system with an energy of 100 J in a 100-ns pulse were used. A decrease in reflectivity occurred at a laser intensity one order of magnitude higher than the parametric-instability threshold. Self-phase modulation of scattered light due to modulational instability was found. A Brillouin-backscattering isotope effect due to the hydrogen and deuterium plasma has also been observed in the red-side part of the SHG-light. Preliminary compression experiments have been carried out using a glass-laser system LETKKO-II, with an energy of 250-1000 J in a ns-pulse. A hologram has been used to study shock waves in the plasma due to the SHG-light converted from the main laser beam. Development of high-power lasers has been promoted, such as disc-glass lasers, E-beam CO 2 lasers and excimer lasers. (author)

  7. Introduction to plasma physics and controlled fusion

    CERN Document Server

    Chen, Francis F

    2016-01-01

    The third edition of this classic text presents a complete introduction to plasma physics and controlled fusion, written by one of the pioneering scientists in this expanding field.  It offers both a simple and intuitive discussion of the basic concepts of the subject matter and an insight into the challenging problems of current research. This outstanding text offers students a painless introduction to this important field; for teachers, a large collection of problems; and for researchers, a concise review of the fundamentals as well as original treatments of a number of topics never before explained so clearly.  In a wholly lucid manner the second edition covered charged-particle motions, plasmas as fluids, kinetic theory, and nonlinear effects.  For the third edition, two new chapters have been added to incorporate discussion of more recent advances in the field.  The new chapter 9 on Special Plasmas covers non-neutral plasmas, pure electron plasmas, solid and ultra-cold plasmas, pair-ion plasmas, d...

  8. Numerical studies of impurities in fusion plasmas

    International Nuclear Information System (INIS)

    Hulse, R.A.

    1982-09-01

    The coupled partial differential equations used to describe the behavior of impurity ions in magnetically confined controlled fusion plasmas require numerical solution for cases of practical interest. Computer codes developed for impurity modeling at the Princeton Plasma Physics Laboratory are used as examples of the types of codes employed for this purpose. These codes solve for the impurity ionization state densities and associated radiation rates using atomic physics appropriate for these low-density, high-temperature plasmas. The simpler codes solve local equations in zero spatial dimensions while more complex cases require codes which explicitly include transport of the impurity ions simultaneously with the atomic processes of ionization and recombination. Typical applications are discussed and computational results are presented for selected cases of interest

  9. Radiative processes in a laser-fusion plasma

    International Nuclear Information System (INIS)

    Campbell, P.M.; Kubis, J.J.; Mitrovich, D.

    1976-01-01

    Plasmas compressed and heated by an intense laser pulse offer promise for the ignition of propagating thermonuclear burn and, ultimately, for use in fusion reactors. It is evident theoretically that the emission and absorption of x-rays by the plasma has a significant effect on the dynamics of the laser compression process. In order to achieve densities high enough for efficient thermonuclear burn, the fusion pellet must be compressed along a low adiabat. This will not be possible if the compressed region of the pellet is significantly preheated by x-rays originating in the hot outer regions. A satisfactory model of compression hydrodynamics must, therefore, include a comprehensive treatment of radiation transport based on a non-LTE model of the plasma. The model must be valid for Fermi-Dirac statistics, since high compression along a low adiabat will, in general, produce degenerate electron distributions. This report is concerned with the plasma model and the corresponding radiation emission and absorption coefficients, including nonthermal processes which occur in the laser deposition region

  10. On interaction of large dust grains with fusion plasma

    International Nuclear Information System (INIS)

    Krasheninnikov, S. I.; Smirnov, R. D.

    2009-01-01

    So far the models used to study dust grain-plasma interactions in fusion plasmas neglect the effects of dust material vapor, which is always present around dust in rather hot and dense edge plasma environment in fusion devices. However, when the vapor density and/or the amount of ionized vapor atoms become large enough, they can alter the grain-plasma interactions. Somewhat similar processes occur during pellet injection in fusion plasma. In this brief communication the applicability limits of the models ignoring vapor effects in grain-plasma interactions are obtained.

  11. Nuclear Fusion Research Understanding Plasma-Surface Interactions

    CERN Document Server

    Clark, Robert E.H

    2005-01-01

    It became clear in the early days of fusion research that the effects of the containment vessel (erosion of "impurities") degrade the overall fusion plasma performance. Progress in controlled nuclear fusion research over the last decade has led to magnetically confined plasmas that, in turn, are sufficiently powerful to damage the vessel structures over its lifetime. This book reviews current understanding and concepts to deal with this remaining critical design issue for fusion reactors. It reviews both progress and open questions, largely in terms of available and sought-after plasma-surface interaction data and atomic/molecular data related to these "plasma edge" issues.

  12. Magnetic confinement fusion plasma theory, Task 1

    International Nuclear Information System (INIS)

    Callen, J.D.

    1991-07-01

    The research performed under this grant during the current year has concentrated on a few key tokamak plasma confinement and heating theory issues: extensive development of a new Chapman-Enskog-like fluid/kinetic hybrid approach to deriving rigorously valid fluid moment equations; applications (neoclassical viscous force, instabilities in the banana-plateau collisionality regime, nonlinear gyroviscous force, unified plasma microinstability equations and their implications, semi-collisional presheath modeling, etc.) of this new formalism; interactions of fluctuating bootstrap-current-driven magnetic islands; determination of net transport processes and equations for a tokamak; and some other topics (extracting more information from heat-pulse-propagation data, modeling of BES fluctuation data, exploring sawtooth effects on energy confinement in DIII-D, divertor X-point modeling). Recent progress and publications in these areas, and in the management of the local NERSC node and fusion theory DECstation 5000 at UW-Madison are summarized briefly in this report

  13. Doppler tomography in fusion plasmas and astrophysics

    DEFF Research Database (Denmark)

    Salewski, Mirko; Geiger, B.; Heidbrink, W. W.

    2015-01-01

    Doppler tomography is a well-known method in astrophysics to image the accretion flow, often in the shape of thin discs, in compact binary stars. As accretion discs rotate, all emitted line radiation is Doppler-shifted. In fast-ion Dα (FIDA) spectroscopy measurements in magnetically confined plasma......, the Dα-photons are likewise Doppler-shifted ultimately due to gyration of the fast ions. In either case, spectra of Doppler-shifted line emission are sensitive to the velocity distribution of the emitters. Astrophysical Doppler tomography has lead to images of accretion discs of binaries revealing bright...... and limits, analogies and differences in astrophysical and fusion plasma Doppler tomography and what can be learned by comparison of these applications....

  14. EMP Fusion

    OpenAIRE

    KUNTAY, Isık

    2010-01-01

    This paper introduces a novel fusion scheme, called EMP Fusion, which has the promise of achieving breakeven and realizing commercial fusion power. The method is based on harnessing the power of an electromagnetic pulse generated by the now well-developed flux compression technology. The electromagnetic pulse acts as a means of both heating up the plasma and confining the plasma, eliminating intermediate steps. The EMP Fusion device is simpler compared to other fusion devices and this reduces...

  15. Brazilian programme for plasma physics and controlled thermonuclear fusion

    International Nuclear Information System (INIS)

    Chian, A.C.L.; Reusch, M.F.; Nascimento, I.C.; Pantuso-Sudano, J.

    1992-01-01

    A proposal for a National Programme of Plasma Physics and Controlled Thermonuclear Fusion in Brazil is presented, aimimg the dissemination of the researchers thought in plasma physics for the national authorities and the scientific community. (E.O.)

  16. NSTX Diagnostics for Fusion Plasma Science Studies

    International Nuclear Information System (INIS)

    Kaita, R.; Johnson, D.; Roquemore, L.; Bitter, M.; Levinton, F.; Paoletti, F.; Stutman, D.

    2001-01-01

    This paper will discuss how plasma science issues are addressed by the diagnostics for the National Spherical Torus Experiment (NSTX), the newest large-scale machine in the magnetic confinement fusion (MCF) program. The development of new schemes for plasma confinement involves the interplay of experimental results and theoretical interpretations. A fundamental requirement, for example, is a determination of the equilibria for these configurations. For MCF, this is well established in the solutions of the Grad-Shafranov equation. While it is simple to state its basis in the balance between the kinetic and magnetic pressures, what they are as functions of space and time are often not easy to obtain. Quantities like the plasma pressure and current density are not directly measurable. They are derived from data that are themselves complex products of more basic parameters. The same difficulties apply to the understanding of plasma instabilities. Not only are the needs for spatial and temporal resolution more stringent, but the wave parameters which characterize the instabilities are difficult to resolve. We will show how solutions to the problems of diagnostic design on NSTX, and the physics insight the data analysis provides, benefits both NSTX and the broader scientific community

  17. Massachusetts Institute of Technology Plasma Fusion Center 1992--1993 report to the President

    International Nuclear Information System (INIS)

    1993-07-01

    This report discusses research being conducted at MIT's plasma fusion center. Some of the areas covered are: plasma diagnostics; rf plasma heating; gyrotron research; treatment of solid waste by arc plasma; divertor experiments; tokamak studies; and plasma and fusion theory

  18. Controllers for high-performance nuclear fusion plasmas

    NARCIS (Netherlands)

    Baar, de M.R.

    2012-01-01

    A succesful nuclear fusion reactor will confine plasma at hig temperatures and densities, with low thermal losses. The workhorse of the nuclear fusion community is the tokamak, a toroidal device in which plasmas are confined by poloidal and toroidal magnetic fields. Ideally, the confirming magnetic

  19. Novel Approach to Plasma Facing Materials in Nuclear Fusion Reactors

    International Nuclear Information System (INIS)

    Livramento, V.; Correia, J. B.; Shohoji, N.; Osawa, E.; Nunes, D.; Carvalho, P. A.; Fernandes, H.; Silva, C.; Hanada, K.

    2008-01-01

    A novel material design in nuclear fusion reactors is proposed based on W-nDiamond nanostructured composites. Generally, a microstructure refined to the nanometer scale improves the mechanical strength due to modification of plasticity mechanisms. Moreover, highly specific grain-boundary area raises the number of sites for annihilation of radiation induced defects. However, the low thermal stability of fine-grained and nanostructured materials demands the presence of particles at the grain boundaries that can delay coarsening by a pinning effect. As a result, the concept of a composite is promising in the field of nanostructured materials. The hardness of diamond renders nanodiamond dispersions excellent reinforcing and stabilization candidates and, in addition, diamond has extremely high thermal conductivity. Consequently, W-nDiamond nanocomposites are promising candidates for thermally stable first-wall materials. The proposed design involves the production of W/W-nDiamond/W-Cu/Cu layered castellations. The W, W-nDiamond and W-Cu layers are produced by mechanical alloying followed by a consolidation route that combines hot rolling with spark plasma sintering (SPS). Layer welding is achieved by spark plasma sintering. The present work describes the mechanical alloying processsing and consolidation route used to produce W-nDiamond composites, as well as microstructural features and mechanical properties of the material produced Long term plasma exposure experiments are planned at ISTTOK and at FTU (Frascati)

  20. Fusion-product energy loss in inertial confinement fusion plasmas with applications to target burns

    International Nuclear Information System (INIS)

    Harris, D.B.; Miley, G.H.

    1984-01-01

    Inertial confinement fusion (ICF) has been proposed as a competitor to magnetic fusion in the drive towards energy production, but ICF target performance still contains many uncertainties. One such area is the energy-loss rate of fusion products. This situation is due in part to the unique plasma parameters encountered in ICF plasmas which are compressed to more than one-thousand times solid density. The work presented here investigates three aspects of this uncertainty

  1. Transition to thermonuclear burn in fusion plasmas

    International Nuclear Information System (INIS)

    Anderson, D.; Hamnen, H.; Lisak, M.

    1991-01-01

    An analytical investigation is made of the time evolution of the 1-D temperature profile in a fusion reactor plasma where the nonlinear energy balance equation is dominated by alpha-particle heating and thermal conduction losses. Special emphasis is given to the problem of establishing sufficient conditions for the transition to thermonuclear burn for given initial temperature profiles. In particular, it is demonstrated that for strongly nonlinear alpha-particle heating, temperature profiles initially peaked on-axis are more easily ignited than profiles similar in form to the equilibrium profile of the energy balance equation. Simple analytical criteria for ignition are established and are shown to compare favourably with results of numerical calculations. (author)

  2. Plasma processed coating of laser fusion targets

    International Nuclear Information System (INIS)

    Johnson, W.L.; Letts, S.A.; Myers, D.W.; Crane, J.K.; Illige, J.D.; Hatcher, C.W.

    1979-01-01

    Coatings for laser fusion targets have been deposited in an inductively coupled discharge device by plasma polymerization. Two feed gases were used: perfluoro-2-butene, which produced a fluorocarbon coating (CF 1 3 ) with a density of 1.8 g/cc, and trans-2-butene which produced a hydrocarbon coating (CH 1 3 ) with a density of 1.0 g/cc. Uniform pin-hole free films have been deposited to a thickness of up to 30 μm of fluorocarbon and up to 110 μm of hydrocarbon. The effect of process variables on surface smoothness has been investigated. The basic defect in the coating has been found to result from shadowing by a small surface irregularity in an anisotropic coating flux

  3. Thermonuclear plasma physic: inertial confinement fusion

    International Nuclear Information System (INIS)

    Bayer, Ch.; Juraszek, D.

    2001-01-01

    Inertial Confinement Fusion (ICF) is an approach to thermonuclear fusion in which the fuel contained in a spherical capsule is strongly compressed and heated to achieve ignition and burn. The released thermonuclear energy can be much higher than the driver energy, making energetic applications attractive. Many complex physical phenomena are involved by the compression process, but it is possible to use simple analytical models to analyze the main critical points. We first determine the conditions to obtain fuel ignition. High thermonuclear gains are achieved if only a small fraction of the fuel called hot spot is used to trigger burn in the main fuel compressed on a low isentrope. A simple hot spot model will be described. The high pressure needed to drive the capsule compression are obtained by the ablation process. A simple Rocket model describe the main features of the implosion phase. Several parameters have to be controlled during the compression: irradiation symmetry, hydrodynamical stability and when the driver is a laser, the problems arising from interaction of the EM wave with the plasma. Two different schemes are examined: Indirect Drive which uses X-ray generated in a cavity to drive the implosion and the Fast Ignitor concept using a ultra intense laser beam to create the hot spot. At the end we present the Laser Megajoule (LMJ) project. LMJ is scaled to a thermonuclear gain of the order of ten. (authors)

  4. Fundamental studies of fusion plasmas. Final report

    International Nuclear Information System (INIS)

    Aamodt, R.E.

    1998-01-01

    Lodestar has carried out a vigorous research program in the areas of rf, edge plasma and divertor physics, with emphasis largely geared towards improving the understanding and performance of ion-cyclotron heating and current drive (ICRF) systems. Additionally, a research program in the field of edge plasma and divertor modeling was initiated. Theoretical work on high power rf sheath formation for multi-strap rf arrays was developed and benchmarked against recent experimental data from the new JET A2 antennas. Sophisticated modeling tools were employed to understand the sheath formation taking into account realistic three-dimensional antenna geometry. A novel physics explanation of an observed anomaly in the low power loading of antennas was applied to qualitatively interpret data on DIII-D in terms of rf sheaths, and potential applications of the idea to develop a near-field sheath diagnostic were explored. Other rf-wave related topics were also investigated. Full wave ICRF modeling studies were carried out in support of ongoing and planned tokamaks experiments, including the investigation of low frequency plasma heating and current drive regimes for IGNITOR. In a cross-disciplinary study involving both MHD and ICRF physics, ponderomotive feedback stabilization by rf was investigated as a potential means of controlling external kink mode disruptions. In another study, the instability of the ion hybrid wave (IHW) in the presence of fusion alpha particles was studied. In the field of edge plasma and divertor modeling studies, Lodestar began the development of a theory of generalized ballooning and sheath instabilities in the scrape off layer (SOL) of divertor tokamaks. A detailed summary of the technical progress in these areas during the contract period is included, as well as where references to published work can be found. A separate listing of publications, meeting abstracts, and other presentations is also given at the end of this final report

  5. Final Report on The Theory of Fusion Plasmas

    International Nuclear Information System (INIS)

    Cowley, Steven C.

    2008-01-01

    Report describes theoretical research in the theory of fusion plasmas funded under grant DE-FG02-04ER54737. This includes work on: explosive instabilities, plasma turbulence, Alfven wave cascades, high beta (pressure) tokamaks and magnetic reconnection. These studies have lead to abetter understanding of fusion plasmas and in particular the future behavior of ITER. More than ten young researchers were involved in this research - some were funded under the grant.

  6. Scaling laws for steady-state fusion plasmas

    Energy Technology Data Exchange (ETDEWEB)

    Husseiny, A A [Carnegie-Mellon Univ., Pittsburgh, Pa. (USA)

    1975-12-01

    Experimental and semi-theoretical scaling laws are extrapolated to include the effect of fusion burn on the lifetime of plasma ions. Fractional burnups are also reconsidered on the same basis. The actual lifetime of fusion plasma ions and the estimated time necessary for feasible reactors, provide a correlation between the laboratory data and the hypothesis of reactor feasibility conditions. Based on these correlations criteria for the realization of self-heated plasmas are established.

  7. Physics of plasma-wall interactions in controlled fusion

    International Nuclear Information System (INIS)

    Post, D.E.; Behrisch, R.

    1984-01-01

    In the areas of plasma physics, atomic physics, surface physics, bulk material properties and fusion experiments and theory, the following topics are presented: the plasma sheath; plasma flow in the sheath and presheath of a scrape-off layer; probes for plasma edge diagnostics in magnetic confinement fusion devices; atomic and molecular collisions in the plasma boundary; physical sputtering of solids at ion bombardment; chemical sputtering and radiation enhanced sublimation of carbon; ion backscattering from solid surfaces; implantation, retention and release of hydrogen isotopes; surface erosion by electrical arcs; electron emission from solid surfaces;l properties of materials; plasma transport near material boundaries; plasma models for impurity control experiments; neutral particle transport; particle confinement and control in existing tokamaks; limiters and divertor plates; advanced limiters; divertor tokamak experiments; plasma wall interactions in heated plasmas; plasma-wall interactions in tandem mirror machines; and impurity control systems for reactor experiments

  8. Plasma flow driven by fusion-generated alpha particles

    International Nuclear Information System (INIS)

    Ikuta, Kazunari.

    1978-05-01

    The confinement of fusion-generated alpha particles will affect the transports of the background plasma particles by the momentum transfer from the energetic alphas. The ions tend to migrate towards the center of plasma (i.e. fuel injection) and electrons towards the plasma periphery. This means the existence of a mechanism which enable to pump out the ashes in the fuel plasma because of the momentum conservation of whole plasma particles. (author)

  9. Plasma Physics and Controlled Nuclear Fusion Research 1971. Vol. III. Proceedings of the Fourth International Conference on Plasma Physics and Controlled Nuclear Fusion Research

    International Nuclear Information System (INIS)

    1971-01-01

    The ultimate goal of controlled nuclear fusion research is to make a new energy source available to mankind, a source that will be virtually unlimited and that gives promise of being environmentally cleaner than the sources currently exploited. This goal has stimulated research in plasma physics over the past two decades, leading to significant advances in the understanding of matter in its most common state as well as to progress in the confinement and heating of plasma. An indication of this progress is that in several countries considerable effort is being devoted to design studies of fusion reactors and to the technological problems that will be encountered in realizing these reactors. This range of research, from plasma physics to fusion reactor engineering, is shown in the present three-volume publication of the Proceedings of the Fourth Conference on Plasma Physics and Controlled Nuclear Fusion Research. The Conference was sponsored by the International Atomic Energy Agency and was held in Madison, Wisconsin, USA from 17 to 23 June 1971. The enthusiastic co-operation of the University of Wisconsin and of the United States Atomic Energy Commission in the organization of the Conference is gratefully acknowledged. The Conference was attended by over 500 scientists from 24 countries and 3 international organizations, and 143 papers were presented. These papers are published here in the original language; English translations of the Russian papers will be published in a Special Supplement to the journal Nuclear Fusion. The series of conferences on Plasma Physics and Controlled Nuclear Fusion Research has become a major international forum for the presentation and discussion of results in this important and challenging field. In addition to sponsoring these conferences, the International Atomic Energy Agency supports controlled nuclear fusion research by publishing the journal Nuclear Fusion, and has recently established an International Fusion Research Council

  10. Progress In Magnetized Target Fusion Driven by Plasma Liners

    Science.gov (United States)

    Thio, Francis Y. C.; Kirkpatrick, Ronald C.; Knapp, Charles E.; Cassibry, Jason; Eskridge, Richard; Lee, Michael; Smith, James; Martin, Adam; Wu, S. T.; Schmidt, George; hide

    2001-01-01

    Magnetized target fusion (MTF) attempts to combine the favorable attributes of magnetic confinement fusion (MCF) for energy confinement with the attributes of inertial confinement fusion (ICF) for efficient compression heating and wall-free containment of the fusing plasma. It uses a material liner to compress and contain a magnetized plasma. For practical applications, standoff drivers to deliver the imploding momentum flux to the target plasma remotely are required. Spherically converging plasma jets have been proposed as standoff drivers for this purpose. The concept involves the dynamic formation of a spherical plasma liner by the merging of plasma jets, and the use of the liner so formed to compress a spheromak or a field reversed configuration (FRC).

  11. Massachusetts Institute of Technology Plasma Fusion Center, 1988--1989 report to the President

    International Nuclear Information System (INIS)

    1989-07-01

    This report discusses the following topics on fusion energy: cold fusion; alcator confinement experiments; applied plasma physics research; fusion systems; coherent electromagnetic wave generation; and fusion technology and engineering

  12. Atomic collisions in fusion plasmas involving multiply charged ions

    International Nuclear Information System (INIS)

    Salzborn, E.

    1980-01-01

    A short survey is given on atomic collisions involving multiply charged ions. The basic features of charge transfer processes in ion-ion and ion-atom collisions relevant to fusion plasmas are discussed. (author)

  13. Study of charged fusion products in laser produced plasmas

    International Nuclear Information System (INIS)

    Rosenblum, M.

    1981-07-01

    Charged reaction products play a central role in inertial confinement fusion. The investigation of the various processes these particles undergo in laser produced plasmas, their influence on the dynamics of the fusion and their utilization as a diagnostic tool are the main subjects of this thesis. (author)

  14. Collective Thomson scattering capabilities to diagnose fusion plasmas

    DEFF Research Database (Denmark)

    Korsholm, Søren Bang; Bindslev, Henrik; Furtula, Vedran

    2010-01-01

    Collective Thomson scattering (CTS) is a versatile technique for diagnosing fusion plasmas. In particular, experiments on diagnosing the ion temperature and fast ion velocity distribution have been executed on a number of fusion devices. In this article the main aim is to describe the technique...

  15. Passive cyclotron current drive for fusion plasmas

    International Nuclear Information System (INIS)

    Kernbichler, W.

    1995-01-01

    The creation of toroidal current using cyclotron radiation in a passive way is, together with the well known bootstrap current, an interesting method for stationary current drive in high-temperature fusion reactors. Here, instead of externally applied RF-waves, fish-scale like structures at the first wall help to create enough asymmetry in the self generated cyclotron radiation intensity to drive a current within the plasma. The problem of computing passive cyclotron current drive consists of actually two linked problems, which are the computation of the electron equilibrium under the presence of self-generated radiation, and the computation of the photon equilibrium in a bounded system with a distorted electron distribution. This system of integro-differential equations cannot be solved directly in an efficient way. Therefore a linearization procedure was developed to decouple both sets of equations, finally linked through a generalized local current drive efficiency. The problem of the exact accounting for the wall profile effects was reduced to the solution of a Fredholm-type integral equation of the 2 nd -kind. Based on all this an extensive computer code was developed to compute the passively driven current as well as radiation losses, radiation transport and overall efficiencies. The results therefrom give an interesting and very detailed insight into the problems related to passive cyclotron current drive

  16. Neutron measurements as fusion plasma diagnostics

    International Nuclear Information System (INIS)

    Nishitani, Takeo; Hoek, M.

    1993-01-01

    Neutron measurements play important roles as the diagnostics of many aspects of the plasma in large tokamak devices such as JT-60U and JET. In the d-d discharges of JT-60U, the most important application of the neutron measurement is the investigation of the fusion performance using fission chambers. The ion velocity distribution function, and the triton slowing down are investigated by the neutron spectrometer and the 14 MeV neutron detector, respectively. TANSY is a combined proton-recoil and neutron time-of flight spectrometer for 14 MeV neutrons to be used during the d-t phase at JET. The detection principle is based on the measurements of the flight time of a scattered initial neutron and the energy of a corresponding recoil proton. The scattering medium is a polyethylene foil. The resolution and efficiency, using a thin foil (0.95 mg/cm 2 ), is 155 keV and 1.4x10 -5 cm 2 , respectively. (author)

  17. Fusion programs in applied plasma physics

    International Nuclear Information System (INIS)

    1992-02-01

    The objectives of the theoretical science program are: To support the interpretation of present experiments and predict the outcome of future planned experiments; to improve on existing models and codes and validate against experimental results; and to conduct theoretical physics development of advanced concepts with applications for DIII-D and future devices. Major accomplishments in FY91 include the corroboration between theory and experiment on MHD behavior in the second stable regime of operation on DIII-D, and the frequency and mode structure of toroidal Alfven eigenmodes in high beta, shaped plasmas. We have made significant advances in the development of the gyro-Landau fluid approach to turbulence simulation which more accurately models kinetic drive and damping mechanisms. Several theoretical models to explain the bifurcation phenomenon in L- to H-mode transition were proposed providing the theoretical basis for future experimental verification. The capabilities of new rf codes have been upgraded in response to the expanding needs of the rf experiments. Codes are being employed to plan for a fully non-inductive current drive experiment in a high beta, enhanced confinement regime. GA's experimental effort in Applied Physics encompasses two advanced diagnostics essential for the operation of future fusion experiments: Alpha particle diagnostic, and current and density profile diagnostics. This paper discusses research in all these topics

  18. Dynamic identification of plasma magnetic contour in fusion machines

    International Nuclear Information System (INIS)

    Bettini, P.; Trevisan, F.; Cavinato, M.

    2005-01-01

    The paper presents a method to identify the plasma magnetic contour in fusion machines, when eddy currents are present in the conducting structures surrounding the plasma. The approach presented is based on the integration of an electromagnetic model of the plasma with a lumped parameters model of the conducting structures around the plasma. This approach has been validated against experimental data from RFX, a reversed field pinch machine. (author)

  19. Magnetized Target Fusion Propulsion: Plasma Injectors for MTF Guns

    Science.gov (United States)

    Griffin, Steven T.

    2003-01-01

    To achieve increased payload size and decreased trip time for interplanetary travel, a low mass, high specific impulse, high thrust propulsion system is required. This suggests the need for research into fusion as a source of power and high temperature plasma. The plasma would be deflected by magnetic fields to provide thrust. Magnetized Target Fusion (MTF) research consists of several related investigations into these topics. These include the orientation and timing of the plasma guns and the convergence and interface development of the "pusher" plasma. Computer simulations of the gun as it relates to plasma initiation and repeatability are under investigation. One of the items under development is the plasma injector. This is a surface breakdown driven plasma generator designed to function at very low pressures. The performance, operating conditions and limitations of these injectors need to be determined.

  20. Laser thermonuclear fusion with force confinement of hot plasma

    International Nuclear Information System (INIS)

    Korobkin, V.V.; Romanovsky, M.Y.

    1994-01-01

    The possibility of the utilization of laser radiation for plasma heating up to thermonuclear temperatures with its simultaneous confinement by ponderomotive force is investigated. The plasma is located inside a powerful laser beam with a tubelike section or inside a cavity of duct section, formed by several intersecting beams focused by cylindrical lenses. The impact of various physical processes upon plasma confinement is studied and the criteria of plasma confinement and maintaining of plasma temperature are derived. Plasma and laser beam stability is considered. Estimates of laser radiation energy necessary for thermonuclear fusion are presented

  1. Two-dimensional Simulations of Correlation Reflectometry in Fusion Plasmas

    International Nuclear Information System (INIS)

    Valeo, E.J.; Kramer, G.J.; Nazikian, R.

    2001-01-01

    A two-dimensional wave propagation code, developed specifically to simulate correlation reflectometry in large-scale fusion plasmas is described. The code makes use of separate computational methods in the vacuum, underdense and reflection regions of the plasma in order to obtain the high computational efficiency necessary for correlation analysis. Simulations of Tokamak Fusion Test Reactor (TFTR) plasma with internal transport barriers are presented and compared with one-dimensional full-wave simulations. It is shown that the two-dimensional simulations are remarkably similar to the results of the one-dimensional full-wave analysis for a wide range of turbulent correlation lengths. Implications for the interpretation of correlation reflectometer measurements in fusion plasma are discussed

  2. Fusion Plasma Physics and ITER - An Introduction (1/4)

    CERN Multimedia

    CERN. Geneva

    2011-01-01

    In November 2006, ministers representing the world’s major fusion research communities signed the agreement formally establishing the international project ITER. Sited at Cadarache in France, the project involves China, the European Union (including Switzerland), India, Japan, the Russian Federation, South Korea and the United States. ITER is a critical step in the development of fusion energy: its role is to confirm the feasibility of exploiting magnetic confinement fusion for the production of energy for peaceful purposes by providing an integrated demonstration of the physics and technology required for a fusion power plant. The ITER tokamak is designed to study the “burning plasma” regime in deuterium-tritium (D-T) plasmas by achieving a fusion amplification factor, Q (the ratio of fusion output power to plasma heating input power), of 10 for several hundreds of seconds with a nominal fusion power output of 500MW. It is also intended to allow the study of steady-state plasma operation at Q≥5 by me...

  3. Novel diagnostics for dust in space, Laboratory and fusion plasmas

    International Nuclear Information System (INIS)

    Castaldo, C.

    2011-01-01

    In situ diagnostics for mobile dust, based on dust impact ionization phenomena, as well as silica aerogel dust collectors are discussed for applications to space and fusion plasmas. The feasibility of an electro-optical probe to detect hypervelocity (>1 km/s) dust particles in tokamaks is evaluated. For quiescent plasmas, a diagnostic of submicron dust based on measurements of plasma fluctuation spectra can be used (copyright 2011 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim) (orig.)

  4. Plasma physics and controlled fusion research during half a century

    Energy Technology Data Exchange (ETDEWEB)

    Lehnert, Bo

    2001-06-01

    A review is given on the historical development of research on plasma physics and controlled fusion. The potentialities are outlined for fusion of light atomic nuclei, with respect to the available energy resources and the environmental properties. Various approaches in the research on controlled fusion are further described, as well as the present state of investigation and future perspectives, being based on the use of a hot plasma in a fusion reactor. Special reference is given to the part of this work which has been conducted in Sweden, merely to identify its place within the general historical development. Considerable progress has been made in fusion research during the last decades. Temperatures above the limit for ignition of self-sustained fusion reactions, i.e. at more than hundred million degrees, have been reached in large experiments and under conditions where the fusion power generation is comparable to the power losses. An energy producing fusion reactor could in principle be realized already today, but it would not become technically and economically efficient when being based on the present state of art. Future international research has therefore to be conducted along broad lines, with necessary ingredients of basic investigations and new ideas.

  5. Plasma physics and controlled fusion research during half a century

    International Nuclear Information System (INIS)

    Lehnert, Bo

    2001-06-01

    A review is given on the historical development of research on plasma physics and controlled fusion. The potentialities are outlined for fusion of light atomic nuclei, with respect to the available energy resources and the environmental properties. Various approaches in the research on controlled fusion are further described, as well as the present state of investigation and future perspectives, being based on the use of a hot plasma in a fusion reactor. Special reference is given to the part of this work which has been conducted in Sweden, merely to identify its place within the general historical development. Considerable progress has been made in fusion research during the last decades. Temperatures above the limit for ignition of self-sustained fusion reactions, i.e. at more than hundred million degrees, have been reached in large experiments and under conditions where the fusion power generation is comparable to the power losses. An energy producing fusion reactor could in principle be realized already today, but it would not become technically and economically efficient when being based on the present state of art. Future international research has therefore to be conducted along broad lines, with necessary ingredients of basic investigations and new ideas

  6. Thermonuclear plasma physic: inertial confinement fusion; Physique des plasmas thermonucleaires: la fusion par confinement inertiel

    Energy Technology Data Exchange (ETDEWEB)

    Bayer, Ch.; Juraszek, D

    2001-07-01

    Inertial Confinement Fusion (ICF) is an approach to thermonuclear fusion in which the fuel contained in a spherical capsule is strongly compressed and heated to achieve ignition and burn. The released thermonuclear energy can be much higher than the driver energy, making energetic applications attractive. Many complex physical phenomena are involved by the compression process, but it is possible to use simple analytical models to analyze the main critical points. We first determine the conditions to obtain fuel ignition. High thermonuclear gains are achieved if only a small fraction of the fuel called hot spot is used to trigger burn in the main fuel compressed on a low isentrope. A simple hot spot model will be described. The high pressure needed to drive the capsule compression are obtained by the ablation process. A simple Rocket model describe the main features of the implosion phase. Several parameters have to be controlled during the compression: irradiation symmetry, hydrodynamical stability and when the driver is a laser, the problems arising from interaction of the EM wave with the plasma. Two different schemes are examined: Indirect Drive which uses X-ray generated in a cavity to drive the implosion and the Fast Ignitor concept using a ultra intense laser beam to create the hot spot. At the end we present the Laser Megajoule (LMJ) project. LMJ is scaled to a thermonuclear gain of the order of ten. (authors)

  7. Thermonuclear Tokamak plasmas in the presence of fusion alpha particles

    International Nuclear Information System (INIS)

    Anderson, D.; Hamnen, H.; Lisak, M.

    1988-01-01

    In this overview, we have focused on several results of the thermonuclear plasma research pertaining to the alpha particle physics and diagnostics in a fusion tokamak plasma. As regards the discussion of alpha particle effects, two distinct classes of phenomena have been distinguished: the simpler class containing phenomena exhibited by individual alpha particles under the influence of bulk plasma properties and, the more complex class including collective effects which become important for increasing alpha particle density. We have also discussed several possibilities to investigate alpha particle effects by simulation experiments using an equivalent population of highly energetic ions in the plasma. Generally, we find that the present theoretical knowledge on the role of fusion alpha particles in a fusion tokamak plasma is incomplete. There are still uncertainties and partial lack of quantitative results in this area. Consequently, further theoretical work and, as far a possible, simulation experiments are needed to improve the situation. Concerning the alpha particle diagnostics, the various diagnostic techniques and the status of their development have been discussed in two different contexts: the escaping alpha particles and the confined alpha particles in the fusion plasma. A general conclusion is that many of the different diagnostic methods for alpha particle measurements require further major development. (authors)

  8. Alpha Heating and Burning Plasmas in Inertial Confinement Fusion.

    Science.gov (United States)

    Betti, R; Christopherson, A R; Spears, B K; Nora, R; Bose, A; Howard, J; Woo, K M; Edwards, M J; Sanz, J

    2015-06-26

    Estimating the level of alpha heating and determining the onset of the burning plasma regime is essential to finding the path towards thermonuclear ignition. In a burning plasma, the alpha heating exceeds the external input energy to the plasma. Using a simple model of the implosion, it is shown that a general relation can be derived, connecting the burning plasma regime to the yield enhancement due to alpha heating and to experimentally measurable parameters such as the Lawson ignition parameter. A general alpha-heating curve is found, independent of the target and suitable to assess the performance of all laser fusion experiments whether direct or indirect drive. The onset of the burning plasma regime inside the hot spot of current implosions on the National Ignition Facility requires a fusion yield of about 50 kJ.

  9. Massachusetts Institute of Technology, Plasma Fusion Center, technical research programs

    International Nuclear Information System (INIS)

    1982-02-01

    Research programs have produced significant results on four fronts: (1) the basic physics of high-temperature fusion plasmas (plasma theory, RF heating, development of advanced diagnostics and small-scale experiments on the Versator tokamak and Constance mirror devices); (2) major confinement results on the Alcator A and C tokamaks, including pioneering investigations of the equilibrium, stability, transport and radiation properties of fusion plasmas at high densities, temperatures and magnetic fields; (3) development of a new and innovative design for axisymmetric tandem mirrors with inboard thermal barriers, with initial operation of the TARA tandem mirror experimental facility scheduled for 1983; and (4) a broadly based program of fusion technology and engineering development that addresses problems in several critical subsystem areas

  10. Fusion plasma physics during half a century

    Energy Technology Data Exchange (ETDEWEB)

    Lehnert, Bo

    1999-08-01

    A review is given on the potentialities of fusion energy with respect to energy production and related environmental problems, the various approaches to controlled thermonuclear fusion, the main problem areas of research, the historical development, the present state of investigations, and future perspectives. This article also presents a personal memorandum of the author. Thereby special reference will be given to part of the research conducted at the Royal Institute of Technology in Stockholm, merely to identify its place within the general historical development. Considerable progress has been made in fusion research during the last decades. In large tokamak experiments temperatures above the ignition limit of about 10{sup 8} K have been reached under break-even conditions where the fusion power generation is comparable to the energy loss. A power producing fusion reactor could in principle be realized already today, but it would not become technically and economically efficient. The future international research programme has therefore to be conducted along broad lines, with necessary ingredients of basis research and new ideas, and also within lines of magnetic confinement being alternative to that of tokamaks.

  11. Fusion plasma physics during half a century

    International Nuclear Information System (INIS)

    Lehnert, Bo

    1999-08-01

    A review is given on the potentialities of fusion energy with respect to energy production and related environmental problems, the various approaches to controlled thermonuclear fusion, the main problem areas of research, the historical development, the present state of investigations, and future perspectives. This article also presents a personal memorandum of the author. Thereby special reference will be given to part of the research conducted at the Royal Institute of Technology in Stockholm, merely to identify its place within the general historical development. Considerable progress has been made in fusion research during the last decades. In large tokamak experiments temperatures above the ignition limit of about 10 8 K have been reached under break-even conditions where the fusion power generation is comparable to the energy loss. A power producing fusion reactor could in principle be realized already today, but it would not become technically and economically efficient. The future international research programme has therefore to be conducted along broad lines, with necessary ingredients of basis research and new ideas, and also within lines of magnetic confinement being alternative to that of tokamaks

  12. Fusion plasma physics research on the H-1 national facility

    International Nuclear Information System (INIS)

    Harris, J.

    1998-01-01

    Full text: Australia has a highly leveraged fusion plasma research program centred on the H-1 National Facility device at the ANU. H-1 is a heliac, a novel helical axis stellarator that was experimentally pioneered in Australia, but has a close correlation with the worldwide research program on toroidal confinement of fusion grade plasma. Experiments are conducted on H-1 by university researchers from the Australian Fusion Research Group (comprising groups from the ANU, the Universities of Sydney, Western Sydney, Canberra, New England, and Central Queensland University) under the aegis of AINSE; the scientists also collaborate with fusion researchers from Japan and the US. Recent experiments on H-1 have focused on improved confinement modes that can be accessed at very low powers in H-1, but allow the study of fundamental physics effects seen on much larger machines at higher powers. H-1 is now being upgraded in magnetic field and heating power, and will be able to confine hotter plasmas beginning in 1999, offering greatly enhanced research opportunities for Australian plasma scientists and engineers, with substantial spillover of ideas from fusion research into other areas of applied physics and engineering

  13. Fusion performance analysis of plasmas with reversed magnetic shear in the Tokamak Fusion Test Reactor

    International Nuclear Information System (INIS)

    Ruskov, E.; Bell, M.; Budny, R.V.; McCune, D.C.; Medley, S.S.; Nazikian, R.; Synakowski, E.J.; Goeler, S. von; White, R.B.; Zweben, S.J.

    1999-01-01

    A case for substantial loss of fast ions degrading the performance of tokamak fusion test reactor plasmas [Phys. Plasmas 2, 2176 (1995)] with reversed magnetic shear (RS) is presented. The principal evidence is obtained from an experiment with short (40 - 70 ms) tritium beam pulses injected into deuterium beam heated RS plasmas [Phys. Rev. Lett. 82, 924 (1999)]. Modeling of this experiment indicates that up to 40% beam power is lost on a time scale much shorter than the beam - ion slowing down time. Critical parameters which connect modeling and experiment are: The total 14 MeV neutron emission, its radial profile, and the transverse stored energy. The fusion performance of some plasmas with internal transport barriers is further deteriorated by impurity accumulation in the plasma core. copyright 1999 American Institute of Physics

  14. 10th International Conference and School on Plasma Physics and Controlled Fusion. Book of Abstracts

    International Nuclear Information System (INIS)

    Anon

    2004-01-01

    About 240 abstracts by Ukrainian and foreign authors submitted to 10-th International Conference and School on Plasma Physics and Controlled fusion have been considered by Conference Program Committee members. All the abstracts have been divided into 8 groups: magnetic confinement systems: stellarators, tokamaks, alternative conceptions; ITER and Fusion reactor aspects; basic plasma physics; space plasma; plasma dynamics and plasma-wall interaction; plasma electronics; low temperature plasma and plasma technologies; plasma diagnostics

  15. Atomic and molecular processes in fusion plasmas

    International Nuclear Information System (INIS)

    Kato, Daiji; Nakamura, Nobuyuki

    2013-01-01

    One of important issues concerning steady state sustainment of magnetically confined plasmas (MCPs) is distribution of impurity ions in the MCPs and radiation powers by the ions. Since tungsten divertors will be used in ITER, the primary element of heavy impurity ions would be tungsten. Tungsten cannot be fully ionized even in core plasmas of ITER. Line radiations by bound electrons of the tungsten ions following electron impact excitations decrease temperatures of the core plasmas. Thus, it is required to keep tungsten concentration in the core plasmas as small as possible. (J.P.N.)

  16. Passive Spectroscopic Diagnostics for Magnetically-confined Fusion Plasmas

    International Nuclear Information System (INIS)

    Stratton, B.C.; Bitter, M.; Hill, K.W.; Hillis, D.L.; Hogan, J.T.

    2007-01-01

    Spectroscopy of radiation emitted by impurities and hydrogen isotopes plays an important role in the study of magnetically-confined fusion plasmas, both in determining the effects of impurities on plasma behavior and in measurements of plasma parameters such as electron and ion temperatures and densities, particle transport, and particle influx rates. This paper reviews spectroscopic diagnostics of plasma radiation that are excited by collisional processes in the plasma, which are termed 'passive' spectroscopic diagnostics to distinguish them from 'active' spectroscopic diagnostics involving injected particle and laser beams. A brief overview of the ionization balance in hot plasmas and the relevant line and continuum radiation excitation mechanisms is given. Instrumentation in the soft X-ray, vacuum ultraviolet, ultraviolet, visible, and near-infrared regions of the spectrum is described and examples of measurements are given. Paths for further development of these measurements and issues for their implementation in a burning plasma environment are discussed.

  17. Passive Spectroscopic Diagnostics for Magnetically-confined Fusion Plasmas

    Energy Technology Data Exchange (ETDEWEB)

    Stratton, B. C.; Biter, M.; Hill, K. W.; Hillis, D. L.; Hogan, J. T.

    2007-07-18

    Spectroscopy of radiation emitted by impurities and hydrogen isotopes plays an important role in the study of magnetically-confined fusion plasmas, both in determining the effects of impurities on plasma behavior and in measurements of plasma parameters such as electron and ion temperatures and densities, particle transport, and particle influx rates. This paper reviews spectroscopic diagnostics of plasma radiation that are excited by collisional processes in the plasma, which are termed 'passive' spectroscopic diagnostics to distinguish them from 'active' spectroscopic diagnostics involving injected particle and laser beams. A brief overview of the ionization balance in hot plasmas and the relevant line and continuum radiation excitation mechanisms is given. Instrumentation in the soft X-ray, vacuum ultraviolet, ultraviolet, visible, and near-infrared regions of the spectrum is described and examples of measurements are given. Paths for further development of these measurements and issues for their implementation in a burning plasma environment are discussed.

  18. Multiple-use plasma laboratory for graduate fusion education

    International Nuclear Information System (INIS)

    Hankins, O.E.; Gilligan, J.G.; Wehring, B.W.; Bourham, M.; Auciello, O.H.

    1989-01-01

    In a climate of tight fusion research and teaching laboratory budgets, it has become necessary to utilize equipment obtained for research purposes in the teaching program. Likewise, it is desirable to use plasma research equipment from nonfusion projects to support basic understanding of general plasma concepts. Multiple experiments can also be done on a single device. The plasma laboratory that has been developed at North Carolina State University in the last 4 yr incorporates all of the aforementioned ideas to support a 3-credit-hour hands-on laboratory course for graduate students. Incorporating teaching and research into the fusion plasma laboratory maximizes the resources and gives students experience on actual research tools. 2 refs

  19. Two component plasma vortex approach to fusion

    International Nuclear Information System (INIS)

    Ikuta, Kazunari.

    1978-09-01

    Two component operation of the field reversed theta pinch plasma by injection of the energetic ion beam with energy of the order of 1 MeV is considered. A possible trapping scheme of the ion beam in the plasma is discussed in detail. (author)

  20. The National Ignition Facility and the Promise of Inertial Fusion Energy

    International Nuclear Information System (INIS)

    Moses, E.I.

    2010-01-01

    The National Ignition Facility (NIF) at the Lawrence Livermore National Laboratory (LLNL) in Livermore, CA, is now operational. The NIF is the world's most energetic laser system capable of producing 1.8 MJ and 500 TW of ultraviolet light. By concentrating the energy from its 192 extremely energetic laser beams into a mm 3 -sized target, NIF can produce temperatures above 100 million K, densities of 1,000 g/cm 3 , and pressures 100 billion times atmospheric pressure - conditions that have never been created in a laboratory and emulate those in planetary interiors and stellar environments. On September 29, 2010, the first integrated ignition experiment was conducted, demonstrating the successful coordination of the laser, cryogenic target system, array of diagnostics and infrastructure required for ignition demonstration. In light of this strong progress, the U.S. and international communities are examining the implication of NIF ignition for inertial fusion energy (IFE). A laser-based IFE power plant will require a repetition rate of 10-20 Hz and a laser with 10% electrical-optical efficiency, as well as further development and advances in large-scale target fabrication, target injection, and other supporting technologies. These capabilities could lead to a prototype IFE demonstration plant in the 10- to 15-year time frame. LLNL, in partnership with other institutions, is developing a Laser Inertial Fusion Engine (LIFE) concept and examining in detail various technology choices, as well as the advantages of both pure fusion and fusion-fission schemes. This paper will describe the unprecedented experimental capabilities of the NIF and the results achieved so far on the path toward ignition. The paper will conclude with a discussion about the need to build on the progress on NIF to develop an implementable and effective plan to achieve the promise of LIFE as a source of carbon-free energy.

  1. The National Ignition Facility and the Promise of Inertial Fusion Energy

    Energy Technology Data Exchange (ETDEWEB)

    Moses, E I

    2010-12-13

    The National Ignition Facility (NIF) at the Lawrence Livermore National Laboratory (LLNL) in Livermore, CA, is now operational. The NIF is the world's most energetic laser system capable of producing 1.8 MJ and 500 TW of ultraviolet light. By concentrating the energy from its 192 extremely energetic laser beams into a mm{sup 3}-sized target, NIF can produce temperatures above 100 million K, densities of 1,000 g/cm{sup 3}, and pressures 100 billion times atmospheric pressure - conditions that have never been created in a laboratory and emulate those in planetary interiors and stellar environments. On September 29, 2010, the first integrated ignition experiment was conducted, demonstrating the successful coordination of the laser, cryogenic target system, array of diagnostics and infrastructure required for ignition demonstration. In light of this strong progress, the U.S. and international communities are examining the implication of NIF ignition for inertial fusion energy (IFE). A laser-based IFE power plant will require a repetition rate of 10-20 Hz and a laser with 10% electrical-optical efficiency, as well as further development and advances in large-scale target fabrication, target injection, and other supporting technologies. These capabilities could lead to a prototype IFE demonstration plant in the 10- to 15-year time frame. LLNL, in partnership with other institutions, is developing a Laser Inertial Fusion Engine (LIFE) concept and examining in detail various technology choices, as well as the advantages of both pure fusion and fusion-fission schemes. This paper will describe the unprecedented experimental capabilities of the NIF and the results achieved so far on the path toward ignition. The paper will conclude with a discussion about the need to build on the progress on NIF to develop an implementable and effective plan to achieve the promise of LIFE as a source of carbon-free energy.

  2. Contributions to the 20. EPS conference on controlled fusion and plasma physics

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1993-07-15

    The Conference covers research on different aspects of plasma physics and fusion technology, like technical aspects of Tokamak devices; plasma instabilities and impurities, development and testing of materials for fusion reactors etc.

  3. First fusion proton measurements in TEXTOR plasmas using

    Czech Academy of Sciences Publication Activity Database

    Bonheure, G.; Mlynář, Jan; Van Wassenhove, G.; Hult, M.; González de Orduña, R.; Lutter, G.; Vermaercke, P.; Huber, A.; Schweer, B.; Esser, G.; Biel, W.

    2012-01-01

    Roč. 83, č. 10 (2012), 10D318 ISSN 0034-6748. [Topical Conference High-Temperature Plasma Diagnostics/19./. Monterey, 06.05.2012-10.05.2012] Institutional research plan: CEZ:AV0Z20430508 Keywords : Tokamak * fusion * activation * diagnostics Subject RIV: BL - Plasma and Gas Discharge Physics Impact factor: 1.602, year: 2012 http://rsi.aip.org/resource/1/rsinak/v83/i10/p10D318_s1

  4. NIFS symposium: toward the research of fusion burning plasmas

    International Nuclear Information System (INIS)

    Itoh, Sanae

    1993-07-01

    NIFS symposium, entitled 'Toward the research of Fusion Burning Plasmas - Present status and Future Strategy' was held at NIFS on July 15th 1992. This NIFS symposium covers various topics related to burning plasma, e.g., JET DT experiment, Plan for DT experiment on TFTR as well as the future trends among researchers. To study the critical issues and trends of future research, a questionnaire was sent to about 100 researchers. This report presents such activities in the NIFS symposium. (author)

  5. Plasma physics and controlled nuclear fusion research 1990. V. 1

    International Nuclear Information System (INIS)

    1991-01-01

    Volume 1 of the Proceedings of the Thirteenth International Conference on Plasma Physics and Controlled Nuclear Fusion Research contains papers given in two of the sessions: A and E. Session A contains the Artsimovich Memorial Lecture and papers on tokamaks; session E papers on plasma heating and current drive. The titles and authors of each paper are listed in the Contents. Abstracts accompany each paper. Refs, figs and tabs

  6. Shock-tube study of fusion plasma-wall interactions

    International Nuclear Information System (INIS)

    Gross, R.A.; Tien, J.K.; Jensen, B.; Panayotou, N.F.; Feinberg, B.

    1977-01-01

    Theoretical and experimental studies have been made of phenomena which occur when a hot (T 1 approximately equal to 6 x 10 6 0 K), dense (n approximately equal to 10 16 cm -3 ), deuterium plasma containing a transverse magnetic field is brought into sudden contact with a cold metal wall. These studies are motivated by the need to understand plasma and metallurgical conditions at the first-wall of a fusion reactor. Experiments were carried out in the Columbia high energy electromagnetic shock tube. Computational simulation was used to investigate the detailed physics of the fusion plasma boundary layer which develops at the wall. The rate of energy transfer from the plasma to the wall was calculated and conditions under which surface melting occurs are estimated. Experimental measurements of plasma-wall heat transfer rates up to 3 x 10 5 watts/cm 2 were obtained and agreement with computed values are good. Fusion reactor first-wall materials have been exposed to 6.0 x 10 21 eV cm -2 (1,000 shots) of deuterium plasma bombardment. Scanning electron micrograph photographs show preferential erosion at grain boundaries, formation of deuterium surface blisters, and evidence of local surface melting. Some cracking is observed along grain boundaries, and a decrease in tensile ductiity is measured

  7. Interpretation of ion cyclotron emission from fusion and space plasmas

    International Nuclear Information System (INIS)

    Dendy, R.O.

    1994-01-01

    Superthermal ion cyclotron emission (ICE) is observed in both fusion and space plasma. Typical spectra display strong peaks at sequential multiple ion cyclotron harmonics, and distinct energetic ion populations are present in the emitting regions. In JET and TFTR, for example, ICE appears to be driven by fusion products or by injected beam ions in the outer mid plane; and in the Earth's ring current, radiation belts, and bow shock, ICE has been observed by the spacecraft OGO 3, GEOS 1 and 2 and AMPTE/IRM, often in conjunction with highly non-Maxwellian proton populations. Common emission mechanisms, arising from collective relaxation of energetic ion populations, appear to operate in both the fusion and space plasma environments. These are reviewed here, and the potential role of ICE as a diagnostic of energetic ion populations is also examined. (Author)

  8. Interplay between parametric instabilities in fusion - relevant laser plasmas

    International Nuclear Information System (INIS)

    Huller, St.

    2003-01-01

    The control of parametric instabilities plays an important role in laser fusion. They are driven by the incident laser beams in the underdense plasma surrounding a fusion capsule and hinder the absorption process of incident laser light which is necessary to heat the fusion target. Due to its high intensity and power, the laser light modifies the plasma density dynamically, such that two or more parametric instabilities compete, in particular stimulated Brillouin scattering and the filamentation instability. The complicated interplay between these parametric instabilities is studied in detail by developing an adequate model accompanied by numerical simulations with multidimensional codes. The model is applied to generic and to smoothed laser beams, which are necessary to limit parametric instabilities, with parameters close to experimental conditions. (author)

  9. Optimal control theory applied to fusion plasma thermal stabilization

    International Nuclear Information System (INIS)

    Sager, G.; Miley, G.; Maya, I.

    1985-01-01

    Many authors have investigated stability characteristics and performance of various burn control schemes. The work presented here represents the first application of optimal control theory to the problem of fusion plasma thermal stabilization. The objectives of this initial investigation were to develop analysis methods, demonstrate tractability, and present some preliminary results of optimal control theory in burn control research

  10. DIAGNOSTICS FOR EROSION AND DEPOSITION PROCESSES IN FUSION PLASMAS

    NARCIS (Netherlands)

    van Rooij, G. J.; Wright, G. M.

    2010-01-01

    An overview is given of the wide range of diagnostics that is providing valuable information on the interaction between plasma and the material wall in a fusion device. Of each technique, a brief description is given in combination with the main advantages and disadvantages for PSI research.

  11. Diagnostics for erosion and deposition processes in fusion plasmas

    NARCIS (Netherlands)

    van Rooij, G. J.; Wright, G. M.

    2012-01-01

    An overview is given of the wide range of diagnostics that is providing valuable information on the interaction between plasma and the material wall in a fusion device. Of each technique, a brief description is given in combination with the main advantages and disadvantages for PSI research.

  12. Diagnostics for erosion and deposition processes in fusion plasmas

    NARCIS (Netherlands)

    van Rooij, G. J.; Wright, G. M.

    2008-01-01

    An overview is given of the wide range of diagnostics that is providing valuable information on the interaction between plasma and the material wall in a fusion device. Of each technique, a brief description is given in combination with the main advantages and disadvantages for PSI research.

  13. Introduction of fusion driven subcritical system plasma design

    International Nuclear Information System (INIS)

    Bin Wu

    2003-01-01

    Fusion driven subcritical nuclear system (FDS) is a multifunctional hybrid reactor, which could breed nuclear fuel, transmute long-lived wastes, producing tritium and so on. This paper presents an introduction of FDS plasma design. Several different advance equilibrium configurations have been proposed and a 1.5-D discharge simulation of FDS was also present

  14. Dust remobilization in fusion plasmas under steady state conditions

    NARCIS (Netherlands)

    Tolias, P.; Ratynskaia, S.; de Angeli, M.; De Temmerman, G.; Ripamonti, D.; Riva, G.; I. Bykov,; Shalpegin, A.; Vignitchouk, L.; Brochard, F.; Bystrov, K.; Bardin, S.; Litnovsky, A.

    2016-01-01

    The first combined experimental and theoretical studies of dust remobilization by plasma forces are reported. The main theoretical aspects of remobilization in fusion devices under steady state conditions are analyzed. In particular, the dominant role of adhesive forces is highlighted and generic

  15. Critical plasma-materials issues for fusion reactor designs

    International Nuclear Information System (INIS)

    Wilson, K.L.; Bauer, W.

    1983-01-01

    Plasma-materials interactions are a dominant driving force in the design of fusion power reactors. This paper presents a summary of plasma-materials interactions research. Emphasis is placed on critical aspects related to reactor design. Particular issues to be addressed are plasma edge characterization, hydrogen recycle, impurity introduction, and coating development. Typical wall fluxes in operating magnetically confined devices are summarized. Recent calculations of tritium inventory and first wall permeation, based on laboratory measurements of hydrogen recycling, are given for various reactor operating scenarios. Impurity introduction/wall erosion mechanisms considered include sputtering, chemical erosion, and evaporation (melting). Finally, the advanced material development for in-vessel components is discussed. (author)

  16. Investigation of metal ions in fusion plasmas using emission spectroscopy

    International Nuclear Information System (INIS)

    Tale, I.

    2005-01-01

    Full text: The Latvian and Portugal Associations are performing development of advanced plasma - facing system using the liquid metal limiter. The objectives of this project require study of the influence of the liquid metal limiter on the main plasma parameters, including concentration of evaporated metal atoms in plasma. The fusion plasmas are related to the dense hot plasmas. The required average ion temperature according to the ITER project (International Thermonuclear Experimental Reactor) is 8,0 keV (9,3 x 10 7 0 K), the average electron temperature - 8,9 keV (1,04 x 10 8 0 K). Plasma temperature operated in the research tokamak ISSTOK, involved in testing of liquid metal limiter concept is considerably less, being of order of 10 50 K. The ionization degree of metal atoms considerably depends on the plasma ion temperature. Density of metal vapours in plasma can be estimated using the following two spectroscopic methods: The fluorescence of the multiple ionised metal ions in steady state concentration; The charge exchange emission during ionisation of evaporated metal ions. In the first step of development of testing system of metal vapours the equipment and instrumentation for charge exchange spectroscopy of Ga and In has been elaborated taking into account the following features of plasma emission. The Ga emission lines occur on the background high temperature plasma black body emission and stray light. Radial distribution of Ga in plasma in the facing plane of Ga flux is desirable

  17. Numerical Experiments Providing New Insights into Plasma Focus Fusion Devices

    Directory of Open Access Journals (Sweden)

    Sing Lee

    2010-04-01

    Full Text Available Recent extensive and systematic numerical experiments have uncovered new insights into plasma focus fusion devices including the following: (1 a plasma current limitation effect, as device static inductance is reduced towards very small values; (2 scaling laws of neutron yield and soft x-ray yield as functions of storage energies and currents; (3 a global scaling law for neutron yield as a function of storage energy combining experimental and numerical data showing that scaling deterioration has probably been interpreted as neutron ‘saturation’; and (4 a fundamental cause of neutron ‘saturation’. The ground-breaking insights thus gained may completely change the directions of plasma focus fusion research.

  18. Fusion programs in applied plasma physics

    International Nuclear Information System (INIS)

    1993-07-01

    This report summarizes the progress made in theoretical and experimental research funded by US Department of Energy Grant No. DE-FG03-92ER54150, during the period July 11, 1992 through May 31, 1993. Four main tasks are reported: applied plasma physics theory, alpha particle diagnostic, edge and current density diagnostic, and plasma rotation drive. The report also discusses the research plans for the theory and experimental programs for the next grant year. Reports and publications supported by the grant during this period are listed in the final section

  19. Laser-plasma interaction physics in the context of fusion

    International Nuclear Information System (INIS)

    Labaune, C.; Fuchs, J.; Depierreux, S.; Tikhonchuk, V.T.; Baldis, H.A.; Pesme, D.; Myatt, J.; Huller, S.; Laval, G.; Tikhonchuk, V.T.

    2000-01-01

    Of vital importance for Inertial Confinement Fusion (ICF) are the understanding and control of the nonlinear processes which can occur during the propagation of the laser pulses through the underdense plasma surrounding the fusion capsule. The control of parametric instabilities has been studied experimentally, using LULI six-beam laser facility, and also theoretically and numerically. New results based on the direct observation of plasma waves with Thomson scattering of a short wavelength probe beam have revealed the occurrence of the Langmuir decay instability. This secondary instability may play an important role in the saturation of stimulated Raman scattering. Another mechanism for inducing the growth of the scattering instabilities is the so-called 'plasma-induced incoherence'. Namely, recent theoretical studies have shown that the propagation of laser beams through the underdense plasma can increase their spatial and temporal incoherence. This plasma-induced beam smoothing can reduce the levels of parametric instabilities. One signature of this process is a large increase of the spectral width of the laser light after propagation through the plasma. Comparison of the experimental results with numerical propagation through the plasma. Comparison of the experimental results with numerical simulations shows an excellent agreement between the observed and calculated time-resolved spectra of the transmitted laser light at various laser intensities. (authors)

  20. Human mesenchymal stem cells and biomaterials interaction: a promising synergy to improve spine fusion.

    Science.gov (United States)

    Barbanti Brodano, G; Mazzoni, E; Tognon, M; Griffoni, C; Manfrini, M

    2012-05-01

    Spine fusion is the gold standard treatment in degenerative and traumatic spine diseases. The bone regenerative medicine needs (i) in vitro functionally active osteoblasts, and/or (ii) the in vivo induction of the tissue. The bone tissue engineering seems to be a very promising approach for the effectiveness of orthopedic surgical procedures, clinical applications are often hampered by the limited availability of bone allograft or substitutes. New biomaterials have been recently developed for the orthopedic applications. The main characteristics of these scaffolds are the ability to induce the bone tissue formation by generating an appropriate environment for (i) the cell growth and (ii) recruiting precursor bone cells for the proliferation and differentiation. A new prototype of biomaterials known as "bioceramics" may own these features. Bioceramics are bone substitutes mainly composed of calcium and phosphate complex salt derivatives. In this study, the characteristics bioceramics bone substitutes have been tested with human mesenchymal stem cells obtained from the bone marrow of adult orthopedic patients. These cellular models can be employed to characterize in vitro the behavior of different biomaterials, which are used as bone void fillers or three-dimensional scaffolds. Human mesenchymal stem cells in combination with biomaterials seem to be good alternative to the autologous or allogenic bone fusion in spine surgery. The cellular model used in our study is a useful tool for investigating cytocompatibility and biological features of HA-derived scaffolds.

  1. Pinch me - I'm fusing. Fusion Power - what is it? What is a z pinch? And why are z-pinches a promising fusion power technology?

    International Nuclear Information System (INIS)

    DERZON, MARK S.

    2000-01-01

    The process of combining nuclei (the protons and neutrons inside an atomic nucleus) together with a release of kinetic energy is called fusion. This process powers the Sun, it contributes to the world stockpile of weapons of mass destruction and may one day generate safe, clean electrical power. Understanding the intricacies of fusion power, promised for 50 years, is sometimes difficult because there are a number of ways of doing it. There is hot fusion, cold fusion and con-fusion. Hot fusion is what powers suns through the conversion of mass energy to kinetic energy. Cold fusion generates con-fusion and nobody really knows what it is. Even so, no one is generating electrical power for you and me with either method. In this article the author points out some basic features of the mainstream approaches taken to hot fusion power, as well as describe why z pinches are worth pursuing as a driver for a power reactor and how it may one day generate electrical power for mankind

  2. How much laser power can propagate through fusion plasma?

    International Nuclear Information System (INIS)

    Lushnikov, Pavel M; Rose, Harvey A

    2006-01-01

    Propagation of intense laser beams is crucial for inertial confinement fusion, which requires precise beam control to achieve the compression and heating necessary to ignite the fusion reaction. The National Ignition Facility (NIF), where fusion will be attempted, is now under construction. Control of intense beam propagation may be ruined by laser beam self-focusing. We have identified the maximum laser beam power that can propagate through fusion plasma without significant self-focusing and have found excellent agreement with recent experimental data. This maximum is determined by the collective forward stimulated Brillouin scattering instability which suggests a way to increase the maximum power by appropriate choice of plasma composition with implication for NIF designs. Our theory also leads to the prediction of anti-correlation between beam spray and backscatter and therefore raises the possibility of indirect control of backscatter through manipulation of plasma ionization state or acoustic damping. We find a simple expression for laser intensity at onset of enhanced beam angular divergence (beam spray)

  3. Thermal energy and bootstrap current in fusion reactor plasmas

    International Nuclear Information System (INIS)

    Becker, G.

    1993-01-01

    For DT fusion reactors with prescribed alpha particle heating power P α , plasma volume V and burn temperature i > ∼ 10 keV specific relations for the thermal energy content, bootstrap current, central plasma pressure and other quantities are derived. It is shown that imposing P α and V makes these relations independent of the magnitudes of the density and temperature, i.e. they only depend on P α , V and shape factors or profile parameters. For model density and temperature profiles analytic expressions for these shape factors and for the factor C bs in the bootstrap current formula I bs ∼ C bs (a/R) 1/2 β p I p are given. In the design of next-step devices and fusion reactors, the fusion power is a fixed quantity. Prescription of the alpha particle heating power and plasma volume results in specific relations which can be helpful for interpreting computer simulations and for the design of fusion reactors. (author) 5 refs

  4. Polarization plasma spectroscopy (PPS) viewed from plasma physics and fusion research

    International Nuclear Information System (INIS)

    Ida, Katsumi

    1998-01-01

    Recently the measurements of poloidal magnetic field become important in plasma physics and nuclear fusion research, since an improved confinement mode associating with a negative magnetic shear has been found. The polarization plasma spectroscopy is recognized to be a useful tool to measure poloidal magnetic field and pitch angle of magnetic field. (author)

  5. Far-infrared fusion plasma diagnostics. Task IIIA. Final report

    International Nuclear Information System (INIS)

    Luhmann, N.C. Jr.

    1986-01-01

    The Task IIIA program at UCLA has been concerned with the development of innovative yet practical plasma diagnostic systems capable of providing detailed information essential to the success of the fusion program but not presently available within the fusion community. Historically, this has involved an initial development in the laboratory, followed by a test of feasibility on the Microtor tokamak prior to transfer of the technique/instrument to main line fusion devices. Strong emphasis has been placed upon the far-infrared (FIR) spectral region where novel diagnostic systems and technology have been developed and then distributed throughout the fusion program. The major diagnostics under development have been the measurement of plasma microturbulence and coherent modes via multichannel cw collective Thomson scattering, and the application of phase/polarization imaging techniques to provide accurate and detailed (>20 channel) electron density and current profiles not presently available using conventional methods. The eventual transfer of the above techniques to main line fusion devices is, of course, a major goal of the UCLA development program. The multichannel scattering development at UCLA was efficiently transferred to TEXT a few years ago. The apparatus has been employed to investigate the strong spectral and spatial asymmetries in the microturbulence uncovered through the unique multichannel and spatial scanning capabilities of the system. The scattering apparatus has also produced evidence for the ion pressure gradient driven eta/sub i/ modes thought responsible for anomalous transport in the edge regions of tokamak plasmas, as well as providing insight into the wave-wave coupling processes between various plasma modes

  6. The plasma-wall interaction region: a key low temperature plasma for controlled fusion

    International Nuclear Information System (INIS)

    Counsell, G F

    2002-01-01

    The plasma-wall interaction region of a fusion device provides the interface between the hot core plasma and the material surfaces. To obtain acceptably low levels of erosion from these surfaces requires most of the power leaving the core to be radiated. This is accomplished in existing devices by encouraging plasma detachment, in which the hot plasma arriving in the region is cooled by volume recombination and ion-neutral momentum transfer with a dense population of neutrals recycled from the surface. The result is a low temperature (1 eV e e >10 19 m -3 ) but weakly ionized (n 0 >10 20 m -3 , n e /n 0 <0.1) plasma found nowhere else in the fusion environment. This plasma provides many of the conditions found in industrial plasmas exploiting plasma chemistry and the presence of carbon in the region (in the form of carbon-fibre composite used in the plasma facing materials) can result in the formation of deposited hydrocarbon films. The plasma-wall interaction region is therefore among the most difficult in fusion to model, requiring an understanding of atomic, molecular and surface physics issues

  7. Introduction to turbulent transport in fusion plasmas

    International Nuclear Information System (INIS)

    Garbet, X.

    2006-01-01

    This introduction presents the main instabilities responsible for turbulence in tokamak plasmas, and the prominent features of the resulting transport. The usual techniques to construct reduced transport models are described. These models can be tested by analysing steady state and transient regimes. Another way to test the theory is to use a similarity principle, similar to the one used in fluid mechanics. Finally, the physics involved in the formation and sustainment of transport barriers is presented. (author)

  8. Control of Internal Transport Barriers in Magnetically Confined Fusion Plasmas

    Science.gov (United States)

    Panta, Soma; Newman, David; Sanchez, Raul; Terry, Paul

    2016-10-01

    In magnetic confinement fusion devices the best performance often involves some sort of transport barriers to reduce the energy and particle flow from core to edge. Those barriers create gradients in the temperature and density profiles. If gradients in the profiles are too steep that can lead to instabilities and the system collapses. Control of these barriers is therefore an important challenge for fusion devices (burning plasmas). In this work we focus on the dynamics of internal transport barriers. Using a simple 7 field transport model, extensively used for barrier dynamics and control studies, we explore the use of RF heating to control the local gradients and therefore the growth rates and shearing rates for barrier initiation and control in self-heated fusion plasmas. Ion channel barriers can be formed in self-heated plasmas with some NBI heating but electron channel barriers are very sensitive. They can be formed in self-heated plasmas with additional auxiliary heating i.e. NBI and radio-frequency(RF). Using RF heating on both electrons and ions at proper locations, electron channel barriers along with ion channel barriers can be formed and removed demonstrating a control technique. Investigating the role of pellet injection in controlling the barriers is our next goal. Work supported by DOE Grant DE-FG02-04ER54741.

  9. Abstracts of the 23rd European physical society conference on controlled fusion and plasma physics

    Energy Technology Data Exchange (ETDEWEB)

    Goutych, I F; Gresillon, D; Sitenko, A G

    1997-12-31

    This document contains the abstracts of the invited and contributed papers presented at 23 EPS conference on controlled fusion and plasma physics. The main contents are: tokamaks, stellarators; alternative magnetic confinement; plasma edge physics; plasma heating and current drive; plasma diagnostics; basic collisionless plasma physics; high intensity laser produced plasmas and inertial confinement; low-temperature plasmas.

  10. Abstracts of the 23rd European physical society conference on controlled fusion and plasma physics

    International Nuclear Information System (INIS)

    Goutych, I.F.; Gresillon, D.; Sitenko, A.G.

    1996-01-01

    This document contains the abstracts of the invited and contributed papers presented at 23 EPS conference on controlled fusion and plasma physics. The main contents are: tokamaks, stellarators; alternative magnetic confinement; plasma edge physics; plasma heating and current drive; plasma diagnostics; basic collisionless plasma physics; high intensity laser produced plasmas and inertial confinement; low-temperature plasmas

  11. Energetic particle instabilities in fusion plasmas

    International Nuclear Information System (INIS)

    Sharapov, S.E.; Alper, B.; Challis, C.D.; Gryaznevich, M.P.; Kiptily, V.G.; Voitsekhovich, I.; Berk, H.L.; Breizman, B.N.; Borba, D.N.; Nabais, F.; Classen, I.G.J.; Edlund, E.M.; Fredrickson, E.D.; Fu, G.Y.; Ghantous, K.; Gorelenkov, N.N.; Kramer, G.J.; Nazikian, R.; Podesta, M.; White, R.B.; Eriksson, J.; Hellesen, C.; Fasoli, A.; Garcia-Munoz, M.; Lauber, P.; Thun, C. Perez von; Gassner, T.; Goloborodko, V.; Schoepf, K.; Yavorskij, V.; Hacquin, S.; Heidbrink, W.W.; Lilley, M.K.; Lisak, M.; Nyqvist, R.; Osakabe, M.; Todo, Y.; Toi, K.; Pinches, S.D.; Porkolab, M.; Shinohara, Koji; Van Zeeland, M.A.

    2012-11-01

    Remarkable progress has been made in diagnosing energetic particle instabilities on present-day machines and in establishing a theoretical framework for describing them. This overview describes the much improved diagnostics of Alfvén instabilities and modelling tools developed world-wide, and discusses progress in interpreting the observed phenomena. A multi-machine comparison is presented giving information on the performance of both diagnostics and modelling tools for different plasma conditions outlining expectations for ITER based on our present knowledge. (author)

  12. Aneutronic fusion in a degenerate plasma

    International Nuclear Information System (INIS)

    Son, S.; Fisch, N.J.

    2004-01-01

    In a Fermi-degenerate plasma, the electronic stopping of a slow ion is smaller than that given by the classical formula, because some transitions between the electron states are forbidden. The bremsstrahlung losses are then smaller, so that the nuclear burning of an aneutronic fuel is more efficient. Consequently, there occurs a parameter regime in which self-burning is possible. Practical obstacles in this regime that must be overcome before net energy can be realized include the compression of the fuel to an ultra dense state and the creation of a hot spot

  13. Aneutronic Fusion in a Degenerate Plasma

    International Nuclear Information System (INIS)

    Son, S.; Fisch, N.J.

    2004-01-01

    In a Fermi-degenerate plasma, the electronic stopping of a slow ion is smaller than that given by the classical formula, because some transitions between the electron states are forbidden. The bremsstrahlung losses are then smaller, so that the nuclear burning of an aneutronic fuel is more efficient. Consequently, there occurs a parameter regime in which self-burning is possible. Practical obstacles in this regime that must be overcome before net energy can be realized include the compression of the fuel to an ultra dense state and the creation of a hot spot

  14. Nuclear Fusion Effects Induced in Intense Laser-Generated Plasmas

    Directory of Open Access Journals (Sweden)

    Lorenzo Torrisi

    2013-01-01

    Full Text Available Deutered polyethylene (CD2n thin and thick targets were irradiated in high vacuum by infrared laser pulses at 1015W/cm2 intensity. The high laser energy transferred to the polymer generates plasma, expanding in vacuum at supersonic velocity, accelerating hydrogen and carbon ions. Deuterium ions at kinetic energies above 4 MeV have been measured by using ion collectors and SiC detectors in time-of-flight configuration. At these energies the deuterium–deuterium collisions may induce over threshold fusion effects, in agreement with the high D-D cross-section valuesaround 3 MeV energy. At the first instants of the plasma generation, during which high temperature, density and ionacceleration occur, the D-D fusions occur as confirmed by the detection of mono-energetic protonsand neutrons with a kinetic energy of 3.0 MeV and 2.5 MeV, respectively, produced by the nuclear reaction. The number of fusion events depends strongly on the experimental set-up, i.e. on the laser parameters (intensity, wavelength, focal spot dimension, target conditions (thickness, chemical composition, absorption coefficient, presence of secondary targets and used geometry (incidence angle, laser spot, secondary target positions.A number of D-D fusion events of the order of 106÷7 per laser shot has been measured.

  15. Plasma-Jet Magneto-Inertial Fusion Burn Calculations

    Science.gov (United States)

    Santarius, John

    2010-11-01

    Several issues exist related to using plasma jets to implode a Magneto-Inertial Fusion (MIF) liner onto a magnetized plasmoid and compress it to fusion-relevant temperatures [1]. The poster will explore how well the liner's inertia provides transient plasma confinement and affects the burn dynamics. The investigation uses the University of Wisconsin's 1-D Lagrangian radiation-hydrodynamics code, BUCKY, which solves single-fluid equations of motion with ion-electron interactions, PdV work, table-lookup equations of state, fast-ion energy deposition, pressure contributions from all species, and one or two temperatures. Extensions to the code include magnetic field evolution as the plasmoid compresses plus dependence of the thermal conductivity on the magnetic field. [4pt] [1] Y.C. F. Thio, et al.,``Magnetized Target Fusion in a Spheroidal Geometry with Standoff Drivers,'' in Current Trends in International Fusion Research, E. Panarella, ed. (National Research Council of Canada, Ottawa, Canada, 1999), p. 113.

  16. Quantitative Characterization of Phosphor Detector for Fusion Plasmas

    International Nuclear Information System (INIS)

    Baciero, A.; Zurro, B.; McCarthy, K. J.

    2004-01-01

    Experiments made to characterize phosphor screens with application as broadband radiation detectors, are described. Several radiation sources, covering the spectral range between the ultraviolet and X ray, were used. In addition, details are given of three original phosphor-screen-based detectors that were designed for use as broadband detectors in magnetically confined fusion devices. The first measurements obtained with these detectors in plasmas created in the TJ-II stellarator device are presented together with the analysis performed. (Author)

  17. Ignition Regime for Fusion in a Degenerate Plasma

    International Nuclear Information System (INIS)

    Son, S.; Fisch, N.J.

    2005-01-01

    We identify relevant parameter regimes in which aneutronic fuels can undergo fusion ignition in hot-ion degenerate plasma. Because of relativistic effects and partial degeneracy, the self-sustained burning regime is considerably larger than previously calculated. Inverse bremsstrahlung plays a major role in containing the reactor energy. We solve the radiation transfer equation and obtain the contribution to the heat conductivity from inverse bremsstrahlung

  18. Discriminant analysis of plasma fusion data

    International Nuclear Information System (INIS)

    Kardaun, O.J.W.F.; Kardaun, J.W.P.F.; Itoh, S.; Itoh, K.

    1992-06-01

    Several discriminant analysis methods has been applied and compared to predict the type of ELM's in H-mode discharges: (a) quadratic discriminant analysis (linear discriminant analysis being a special case), (b) discrimination by non-parametric (kernel-) density estimates, and (c) discrimination by a product multinomial model on a discretised scale. Practical evaluation was performed using SAS in the first two cases, and INDEP, a standard FORTRAN program, initially developed for medical applications, in the last case. We give here a flavour of the approach and its results. In summary, discriminant analysis can be used as a useful descriptive method of specifying regions where particular types of plasma discharges can be produced. Parametric methods have the advantage of a rather compact mathematical formulation . Pertinent graphical representations are useful to make the theory and the results more palatable to the experimental physicists. (J.P.N.)

  19. Laser fusion implosion and plasma interaction experiments

    International Nuclear Information System (INIS)

    Ahlstrom, H.G.

    1977-08-01

    Results related to the propagation, absorption and scattering of laser light by both spherical and planar targets are described. The absorption measurements indicate that for intensities of interest, inverse bremsstrahlung is not the dominant absorption mechanism. The laser light scattered by the plasma is polarization dependent and provides evidence that Brillouin scattering and resonance absorption are operative. Special diagnostics have been designed and experiments have been performed to elucidate the nature of these two processes. Implosion results on glass microshell targets filled with DT gas are also summarized. These experiments are for targets intentionally operated in the portion of parameter space characteristic of exploding pusher events. Experiments have been performed over a yield range from 0 to 10 9 neutrons per event. It is shown how this data can be normalized with a simple scaling law

  20. Characterization of an electrothermal plasma source for fusion transient simulations

    Science.gov (United States)

    Gebhart, T. E.; Baylor, L. R.; Rapp, J.; Winfrey, A. L.

    2018-01-01

    The realization of fusion energy requires materials that can withstand high heat and particle fluxes at the plasma material interface. In this work, an electrothermal (ET) plasma source has been designed as a transient heat flux source for a linear plasma material interaction device. An ET plasma source operates in the ablative arc regime driven by a DC capacitive discharge. The current channel width is defined by the 4 mm bore of a boron nitride liner. At large plasma currents, the arc impacts the liner wall, leading to high particle and heat fluxes to the liner material, which subsequently ablates and ionizes. This results in a high density plasma with a large unidirectional bulk flow out of the source exit. The pulse length for the ET source has been optimized using a pulse forming network to have durations of 1 and 2 ms. The peak currents and maximum source energies seen in this system are 1.9 kA and 1.2 kJ for the 2 ms pulse and 3.2 kA and 2.1 kJ for the 1 ms pulse, respectively. This work is a proof of the principal project to show that an ET source produces electron densities and heat fluxes comparable to those anticipated in transient events in large future magnetic confinement fusion devices. Heat flux, plasma temperature, and plasma density were determined for each shot using infrared imaging and optical spectroscopy techniques. This paper will discuss the assumptions, methods, and results of the experiments.

  1. The role of alpha particles in magnetically confined fusion plasmas

    International Nuclear Information System (INIS)

    Lisak, M.; Wilhelmsson, H.

    1986-01-01

    Recent progress in the confinement of hot plasmas in magnetic fusion experiments throughout the world has intensified interest and research in the physics of D-T burning plasmas especially in the wide range of unresolved theoretical as well as experimental questions associated with the role of alpha particles in such devices. In order to review the state-of-the- art in this field, and to identify new issues and problems for further research, the Symposium on the Role of Alpha Particles in Magnetically Confined Fusion Plasmas was held from 24 to 26 June 1986 at Aspenaesgaarden near Goeteborg, Sweden. About 25 leading experts from nine countries attended the Symposium and gave invited talks. The major part of the programme was devoted to alpha-particle effects in tokamaks but some aspects of open systems were also discussed. The possibilities of obtaining ignition in JET and TFTR as well as physics issues for the compact ignition experiments were considered in particular. A special session was devoted to the diagnostics of alpha particles and other fusion products. In this report are summarised some of the highlights of the symposium. (authors)

  2. Material Challenges For Plasma Facing Components in Future Fusion Reactors

    International Nuclear Information System (INIS)

    Linke, J; Pintsuk, G.; Rödig, M.

    2013-01-01

    Increasing attention is directed towards thermonuclear fusion as a possible future energy source. Major advantages of this energy conversion technology are the almost inexhaustible resources and the option to produce energy without CO2-emissions. However, in the most advanced field of magnetic plasma confinement a number of technological challenges have to be met. In particular high-temperature resistant and plasma compatible materials have to be developed and qualified which are able to withstand the extreme environments in a commercial thermonuclear power reactor. The plasma facing materials (PFMs) and components (PFCs) in such fusion devices, i.e. the first wall (FW), the limiters and the divertor, are strongly affected by the plasma wall interaction processes and the applied intense thermal loads during plasma operation. On the one hand, these mechanisms have a strong influence on the plasma performance; on the other hand, they have major impact on the lifetime of the plasma facing armour. In present-day and next step devices the resulting thermal steady state heat loads to the first wall remain below 1 MWm-2; the limiters and the divertor are expected to be exposed to power densities being at least one order of magnitude above the FW-level, i.e. up to 20 MWm-2 for next step tokamaks such as ITER or DEMO. These requirements are responsible for high demands on the selection of qualified PFMs and heat sink materials as well as reliable fabrication processes for actively cooled plasma facing components. The technical solutions which are considered today are mainly based on the PFMs beryllium, carbon or tungsten joined to copper alloys or stainless steel heat sinks. In addition to the above mentioned quasi-stationary heat loads, short transient thermal pulses with deposited energy densities up to several tens of MJm-2 are a serious concern for next step tokamak devices. The most frequent events are so-called Edge Localized Modes (type I ELMs) and plasma disruptions

  3. Alushta-2012. International Conference-School on Plasma Physics and Controlled Fusion and the Adjoint Workshop 'Nano-and micro-sized structures in plasmas'. Book of Abstracts

    International Nuclear Information System (INIS)

    Makhlaj, V.A.

    2012-01-01

    The Conference was devoted to a new valuable information about the present status of plasma physics and controlled fusion research. The main topics was : magnetic confinement systems; plasma heating and current drive; ITER and fusion reactor aspects; basic plasma physics; space plasma; plasma dynamics and plasma-wall interaction; plasma electronics; low temperature plasma and plasma technologies; plasma diagnostics; formation of nano-and micro-sized structures in plasmas; properties of plasmas with nano- and micro- objects

  4. Magneto-inertial Fusion: An Emerging Concept for Inertial Fusion and Dense Plasmas in Ultrahigh Magnetic Fields

    Energy Technology Data Exchange (ETDEWEB)

    Thio, Francis Y.C.

    2008-01-01

    An overview of the U.S. program in magneto-inertial fusion (MIF) is given in terms of its technical rationale, scientific goals, vision, research plans, needs, and the research facilities currently available in support of the program. Magneto-inertial fusion is an emerging concept for inertial fusion and a pathway to the study of dense plasmas in ultrahigh magnetic fields (magnetic fields in excess of 500 T). The presence of magnetic field in an inertial fusion target suppresses cross-field thermal transport and potentially could enable more attractive inertial fusion energy systems. A vigorous program in magnetized high energy density laboratory plasmas (HED-LP) addressing the scientific basis of magneto-inertial fusion has been initiated by the Office of Fusion Energy Sciences of the U.S. Department of Energy involving a number of universities, government laboratories and private institutions.

  5. Quantitative Characterization of Phosphor Detector for Fusion Plasmas; Caracterizacion Cuantitativa de Detectores Luminiscentes para Plasmas de Fusion

    Energy Technology Data Exchange (ETDEWEB)

    Baciero, A; Zurro, B; McCarthy, K J

    2004-07-01

    Experiments made to characterize phosphor screens with application as broadband radiation detectors, are described. Several radiation sources, covering the spectral range between the ultraviolet and X ray, were used. In addition, details are given of three original phosphor-screen-based detectors that were designed for use as broadband detectors in magnetically confined fusion devices. The first measurements obtained with these detectors in plasmas created in the TJ-II stellarator device are presented together with the analysis performed. (Author)

  6. XHM-1 alloy as a promising structural material for water-cooled fusion reactor components

    International Nuclear Information System (INIS)

    Solonin, M.I.; Alekseev, A.B.; Kazennov, Yu.I.; Khramtsov, V.F.; Kondrat'ev, V.P.; Krasina, T.A.; Rechitsky, V.N.; Stepankov, V.N.; Votinov, S.N.

    1996-01-01

    Experience gained in utilizing austenitic stainless steel components in water-cooled power reactors indicates that the main cause of their failure is the steel's propensity for corrosion cracking. In search of a material immune to this type of corrosion, different types of austenitic steels and chromium-nickel alloys were investigated and tested at VNIINM. This paper presents the results of studying physical and mechanical properties, irradiation and corrosion resistance in a water coolant at <350 C of the alloy XHM-1 as compared with austenitic stainless steels 00Cr16Ni15Mo3Nb, 00Cr20Ni25Nb and alloy 00Cr20Ni40Mo5Nb. Analysis of the results shows that, as distinct from the stainless steels studied, the XHM-1 alloy is completely immune to corrosion cracking (CC). Not a single induced damage was encountered within 50 to 350 C in water containing different amounts of chlorides and oxygen under tensile stresses up to the yield strength of the material. One more distinctive feature of the alloy compared to steels is that no change in the strength or total elongation is encountered in the alloy specimens irradiated to 32 dpa at 350 C. The XHM-1 alloy has adequate fabricability and high weldability characteristics. As far as its properties are concerned, the XHM-1 alloy is very promising as a material for water-cooled fusion reactor components. (orig.)

  7. Atomic and plasma-material interaction data for fusion. V. 6

    International Nuclear Information System (INIS)

    1995-01-01

    Volume 6 of the supplement ''atomic and plasma-material interaction data for fusion'' to the journal ''Nuclear Fusion'' includes critical assessments and results of original experimental and theoretical studies on inelastic collision processes among the basic and dominant impurity constituents of fusion plasmas. Processes considered in the 15 papers constituting this volume are: electron impact excitation of excited Helium atoms, electron impact excitation and ionization of plasma impurity ions and atoms, electron-impurity-ion recombination and excitation, ionization and electron capture in collisions of plasma protons and impurity ions with the main fusion plasma neutral components helium and atomic and molecular hydrogen. Refs, figs, tabs

  8. High Temperature Plasmas Theory and Mathematical Tools for Laser and Fusion Plasmas

    CERN Document Server

    Spatschek, Karl-Heinz

    2012-01-01

    Filling the gap for a treatment of the subject as an advanced course in theoretical physics with a huge potential for future applications, this monograph discusses aspects of these applications and provides theoretical methods and tools for their investigation. Throughout this coherent and up-to-date work the main emphasis is on classical plasmas at high-temperatures, drawing on the experienced author's specialist background. As such, it covers the key areas of magnetic fusion plasma, laser-plasma-interaction and astrophysical plasmas, while also including nonlinear waves and phenomena.

  9. Ion irradiated graphite exposed to fusion-relevant deuterium plasma

    International Nuclear Information System (INIS)

    Deslandes, Alec; Guenette, Mathew C.; Corr, Cormac S.; Karatchevtseva, Inna; Thomsen, Lars; Ionescu, Mihail; Lumpkin, Gregory R.; Riley, Daniel P.

    2014-01-01

    Graphite samples were irradiated with 5 MeV carbon ions to simulate the damage caused by collision cascades from neutron irradiation in a fusion environment. The ion irradiated graphite samples were then exposed to a deuterium plasma in the linear plasma device, MAGPIE, for a total ion fluence of ∼1 × 10 24 ions m −2 . Raman and near edge X-ray absorption fine structure (NEXAFS) spectroscopy were used to characterize modifications to the graphitic structure. Ion irradiation was observed to decrease the graphitic content and induce disorder in the graphite. Subsequent plasma exposure decreased the graphitic content further. Structural and surface chemistry changes were observed to be greatest for the sample irradiated with the greatest fluence of MeV ions. D retention was measured using elastic recoil detection analysis and showed that ion irradiation increased the amount of retained deuterium in graphite by a factor of four

  10. Trends in laser-plasma-instability experiments for laser fusion

    International Nuclear Information System (INIS)

    Drake, R.P.

    1991-01-01

    Laser-plasma instability experiments for laser fusion have followed three developments. These are advances in the technology and design of experiments, advances in diagnostics, and evolution of the design of high-gain targets. This paper traces the history of these three topics and discusses their present state. Today one is substantially able to produce controlled plasma conditions and to diagnose specific instabilities within such plasmas. Experiments today address issues that will matter for future laser facilities. Such facilities will irradiate targets with ∼1 MJ of visible or UV light pulses that are tens of nanoseconds in duration, very likely with a high degree of spatial and temporal incoherence. 58 refs., 4 figs

  11. Plasma fluctuations and confinement of fusion reaction products

    International Nuclear Information System (INIS)

    Coppi, B.; Pegoraro, F.

    1981-01-01

    The interaction between the fluctuations that can be excited in a magnetically confined plasma and the high-energy-particle population produced by fusion reactions is analyzed in view of its relevance to the process of thermonuclear ignition. The spectrum of the perturbations that, in the absence of fusion reaction products, would be described by the incompressible ideal magnetohydrodynamic approximation is studied considering finite value of the plasma pressure relative ot the magnetic pressure. The combined effects of the magnetic field curvature and shear are taken into account and the relevant spectrum is shown to consist of a continuous portion, that could be identified as a mixture of shear-Alfven and interchange oscillations, and a discrete unstable part corresponding to the so-called ballooning modes. The rate of diffusion of the fusion reaction products induced by oscillations in the continuous part of the spectrum, as estimated from the appropriate quasi-linear theory, is found to be significantly smaller than could be expected if normal modes (i.e., nonconvective solutions) were excited. However, a relatively wide intermediate region is identified where opalescent fluctuations, capable of achieving significant amplitudes and corresponding to a quasi-discrete spectrum, can be excited

  12. Characterization of a deuterium-deuterium plasma fusion neutron generator

    Science.gov (United States)

    Lang, R. F.; Pienaar, J.; Hogenbirk, E.; Masson, D.; Nolte, R.; Zimbal, A.; Röttger, S.; Benabderrahmane, M. L.; Bruno, G.

    2018-01-01

    We characterize the neutron output of a deuterium-deuterium plasma fusion neutron generator, model 35-DD-W-S, manufactured by NSD/Gradel-Fusion. The measured energy spectrum is found to be dominated by neutron peaks at 2.2 MeV and 2.7 MeV. A detailed GEANT4 simulation accurately reproduces the measured energy spectrum and confirms our understanding of the fusion process in this generator. Additionally, a contribution of 14 . 1 MeV neutrons from deuterium-tritium fusion is found at a level of 3 . 5%, from tritium produced in previous deuterium-deuterium reactions. We have measured both the absolute neutron flux as well as its relative variation on the operational parameters of the generator. We find the flux to be proportional to voltage V 3 . 32 ± 0 . 14 and current I 0 . 97 ± 0 . 01. Further, we have measured the angular dependence of the neutron emission with respect to the polar angle. We conclude that it is well described by isotropic production of neutrons within the cathode field cage.

  13. Atomic and plasma-material interaction data for fusion. V. 2

    International Nuclear Information System (INIS)

    1992-01-01

    This issues of the Atomic and Plasma-Material Interaction Data for Fusion contains 9 papers on atomic and molecular processes in the edge region of magnetically confined fusion plasmas, including spectroscopic data for fusion edge plasmas; electron collision processes with plasma edge neutrals; electron-ion collisions in the plasma edge; cross-section data for collisions of electrons with hydrocarbon molecules; dissociative and energy transfer reactions involving vibrationally excited hydrogen or deuterium molecules; an assessment of ion-atom collision data for magnetic fusion plasma edge modeling; an extended scaling of cross sections for the ionization of atomic and molecular hydrogen as well as helium by multiply-charged ions; ion-molecule collision processes relevant to fusion edge plasmas; and radiative losses and electron cooling rates for carbon and oxygen plasma impurities. Refs, figs and tabs

  14. Ultrasmooth plasma polymerized coatings for laser-fusion targets

    International Nuclear Information System (INIS)

    Letts, S.A.; Myers, D.W.; Witt, L.A.

    1980-01-01

    Coatings for laser fusion targets were deposited up to 135 μm thick by plasma polymerization onto 140 μm diameter DT filled glass microspheres. Ultrasmooth surfaces (no defect higher than 0.1 μm) were achieved by eliminating particulate contamination. Process generated particles were eliminated by determining the optimum operating conditions of power, gas flow, and pressure, and maintaining these conditions through feedback control. From a study of coating defects grown over known surface irregularities, a quantitative relationship between irregularity size, film thickness, and defect size was determined. This relationship was used to set standards for the maximum microshell surface irregularity tolerable in the production of hydrocarbon or fluorocarbon coated laser fusion targets

  15. Ultrasmooth plasma polymerized coatings for laser fusion targets

    International Nuclear Information System (INIS)

    Letts, S.A.; Myers, D.W.; Witt, L.A.

    1980-01-01

    Coatings for laser fusion were deposited up to 135μm thick by plasma polymerization onto 140 μm diameter DT filled glass microspheres. Ultrasmooth surfaces (no defect higher than 0.1 μm) were achieved by eliminating particulate contamination. Process generated particles were eliminated by determining the optimum operating conditions of power (20 watts), gas flow (0.3 sccm trans-2-butene, 10.0 sccm hydrogen), and pressure (75 millitorr), and maintaining these conditions through feedback control. From a study of coating defects grown over known surface irregularities, a quantitative relationship between irregularity size, film thickness, and defect size was determined. This relationship was used to set standards for the maximum microshell surface irregularity tolerable in the production of hydrocarbon or fluorocarbon coated laser fusion targets

  16. Nuclear fusion research and plasma application technologies in SWIP (Southwestern Institute of Physics)

    International Nuclear Information System (INIS)

    Deng, X.W.

    1990-01-01

    A brief introduction of nuclear fusion research and plasma application technologies in SWIP is reported in this paper. The SWIP focuses its fusion efforts mainly on Tokamak with mirror as the supplemental experiments and fusion reactor conceptual design as preparation for future application of fusion energy. SWIP is making great efforts on fusion technology spin-off to make contribution towards national economic construction. (Author)

  17. An accelerated beam-plasma neutron/proton source and early application of a fusion plasma

    International Nuclear Information System (INIS)

    Ohnishi, M.; Yoshikawa, K.; Yamamoto, Y.; Hoshino, C.; Masuda, K.; Miley, G.; Jurczyk, B.; Stubbers, R.; Gu, Y.

    1999-01-01

    We measured the number of the neutrons and protons produced by D-D reactions in an accelerated beam-plasma fusion and curried out the numerical simulations. The linear dependence of the neutron yield on a discharge current indicates that the fusion reactions occur between the background gas and the fast particles. i.e. charge exchanged neutrals and accelerated ions. The neutron yield divided by (fusion cross section x ion current x neutral gas pressure) still possesses the dependence of the 1.2 power of discharge voltage. which shows the fusion reactions are affected by the electrostatic potential built-up in the center. The measured proton birth profiles suggest the existence of a double potential well, which is supported by the numerical simulations. (author)

  18. Studies on the parametric decay of waves in fusion plasmas

    International Nuclear Information System (INIS)

    Paettikangas, T.

    1992-08-01

    Parametric instabilities of large-amplitude electromagnetic waves are investigated in fusion applications. In laser fusion, the electromegnetic wave reflected from the overdense plasma can act as a secondary pump wave and exite parametric instabilities. In double simulated Brilloun scattering (DSBS), both the incoming and the reflected pump wave scatter from a common ion sound wave. The stationary states and the dynamics of DSBS are investigated by using a simple envelope model. The ion sound wave that is exited in DSBS is shown to have soliton-like properties. The simulated Raman scattering (SRS) of free-electron-laser radiation can be applied to current drive in tokamaks. SRS generates fast longitudinal electron plasma waves which accelerate electrons to relativistic energies. Since the energetic current-carrying electrons are almost collisionless, the current decays very slowly. The feasibility of the Raman current drive in tokamaks is investigated theoretically. The current drive efficiency and the optimum free-electron-laser parameters are determined. The energy transfer to the fast electrons from the electrostatic wave is studied with relativistic Vlasov-Maxwell simulations. The parametric decay of a wave to half-harmonics is investigated. It is shown that the growth rate of the decay vanishes in the limit of a long wavelenght of the pump wave even for general electromagnetic or electrostatic decay models. The results are applied to the decay of a fast magnetosonic waves in tokamak plasmas. (orig.)

  19. BOOK REVIEW: Fundamentals of Plasma Physics and Controlled Fusion

    Science.gov (United States)

    Brambilla, Marco

    1998-04-01

    Professor Kenro Miyamoto, already well known for his textbook Plasma Physics for Nuclear Fusion (MIT Press, Cambridge, MA, 1976; revised edition 1989), has now published a new book entitled Fundamentals of Plasma Physics and Controlled Fusion (Iwanami Book Service Center, Tokyo, 1997). To a large extent, the new book is a somewhat shortened and well reorganized version of its predecessor. The style, concise and matter of fact, clearly shows the origin of the text in lectures given by the author to graduate students. As announced by the title, the book is divided into two parts: the first part (about 250 pages) is a general introduction to the physics of plasmas, while the second, somewhat shorter, part (about 150 pages), is devoted to a description of the most important experimental approaches to achieving controlled thermonuclear fusion. Even in the first part, moreover, the choice of subjects is consistently oriented towards the needs of fusion research. Thus, the introduction to the behaviour of charged particles (particle motion, collisions, etc.) and to the collective description of plasmas is quite short, although the reader will get a flavour of all the most important topics and will find a number of examples chosen for their relevance to fusion applications (only the presentation of the Vlasov equation, in the second section of Chapter 4, might be criticized as so concise as to be almost misleading, since the difference between microscopic and macroscopic fields is not even mentioned). Considerably more space is devoted to the magnetohydrodynamic (MHD) description of equilibrium and stability. This part includes the solution of the Grad-Shafranov equation for circular tokamaks, a brief discussion of Pfirsch-Schlüter, neoclassical and anomalous diffusion, and two relatively long chapters on the most important ideal and resistive MHD instabilities of toroidal plasmas; drift and ion temperature gradient driven instabilities are also briefly presented. The

  20. Spectrum analysis of hydrogen plasma in spherically convergent beam fusion

    International Nuclear Information System (INIS)

    Ogasawara, Kazuki; Yamauchi, Kunihito; Watanabe, Masato; Sunaga, Yoshitaka; Hotta, Eiki; Okino, Akitoshi

    2001-01-01

    Spectroscopic analysis of spherical glow discharge fusion device was carried out using hydrogen gas. Effects of the discharge current and cathode voltage on spectrum profiles of hydrogen Balmar lines were measured. The profiles of all hydrogen lines were broadened with the cathode voltage. From the relationship between the maximum broadening width and the cathode voltage, it was indicated that the broadening was caused by the Doppler effect. From the spatial distribution of emission intensity, it was found that plasma core size became larger with discharge current and smaller with cathode voltage. (author)

  1. Interaction of ion clusters with fusion plasmas: Scaling laws

    International Nuclear Information System (INIS)

    Arista, N.R.; Bringa, E.M.

    1997-01-01

    The interaction between large ion clusters or very intense ion beams with fusion plasma is studied using the dielectric function formalism with appropriate quantum corrections. The contributions from individual and collective modes to the energy loss are calculated. The general properties of the interference effects are characterized in terms of the relevant parameters, and simple scaling laws are obtained. In particular, the conditions for a maximum enhancement in the energy deposition are derived. The study provides a unified view and a general formulation of collective effects in the energy loss for low and high velocities of the beam particles. copyright 1997 The American Physical Society

  2. Spectrum analysis of hydrogen plasma in spherically convergent beam fusion

    Energy Technology Data Exchange (ETDEWEB)

    Ogasawara, Kazuki; Yamauchi, Kunihito; Watanabe, Masato; Sunaga, Yoshitaka; Hotta, Eiki [Tokyo Institute of Technology, Dept. of Energy Sciences, Yokohama, Kanagawa (Japan); Okino, Akitoshi [Tokyo Institute of Technology, Dept. of Electrical and Electronic Engineering, Tokyo (Japan)

    2001-09-01

    Spectroscopic analysis of spherical glow discharge fusion device was carried out using hydrogen gas. Effects of the discharge current and cathode voltage on spectrum profiles of hydrogen Balmar lines were measured. The profiles of all hydrogen lines were broadened with the cathode voltage. From the relationship between the maximum broadening width and the cathode voltage, it was indicated that the broadening was caused by the Doppler effect. From the spatial distribution of emission intensity, it was found that plasma core size became larger with discharge current and smaller with cathode voltage. (author)

  3. High density plasmas formation in Inertial Confinement Fusion and Astrophysics

    International Nuclear Information System (INIS)

    Martinez-Val, J. M.; Minguez, E.; Velarde, P.; Perlado, J. M.; Velarde, G.; Bravo, E.; Eliezer, S.; Florido, R.; Garcia Rubiano, J.; Garcia-Senz, D.; Gil de la Fe, J. M.; Leon, P. T.; Martel, P.; Ogando, F.; Piera, M.; Relano, A.; Rodriguez, R.; Garcia, C.; Gonzalez, E.; Lachaise, M.; Oliva, E.

    2005-01-01

    In inertially confined fusion (ICF), high densities are required to obtain high gains. In Fast Ignition, a high density, low temperature plasma can be obtained during the compression. If the final temperature reached is low enough, the electrons of the plasma can be degenerate. In degenerate plasmas. Bremsstrahlung emission is strongly suppressed an ignition temperature becomes lower than in classical plasmas, which offers a new design window for ICF. The main difficulty of degenerate plasmas in the compression energy needed for high densities. Besides that, the low specific heat of degenerate electrons (as compared to classical values) is also a problem because of the rapid heating of the plasma. Fluid dynamic evolution of supernovae remnants is a very interesting problem in order to predict the thermodynamical conditions achieved in their collision regions. Those conditions have a strong influence in the emission of light and therefore the detection of such events. A laboratory scale system has been designed reproducing the fluid dynamic field in high energy experiments. The evolution of the laboratory system has been calculated with ARWEN code, 2D Radiation CFD that works with Adaptive Mesh Refinement. Results are compared with simulations on the original system obtained with a 3D SPH astrophysical code. New phenomena at the collision plane and scaling of the laboratory magnitudes will be described. Atomic physics for high density plasmas has been studied with participation in experiments to obtain laser produced high density plasmas under NLTE conditions, carried out at LULI. A code, ATOM3R, has been developed which solves rate equations for optically thin plasmas as well as for homogeneous optically thick plasmas making use of escape factors. New improvements in ATOM3R are been done to calculate level populations and opacities for non homogeneous thick plasmas in NLTE, with emphasis in He and H lines for high density plasma diagnosis. Analytical expression

  4. Effect of a generalized particle momentum distribution on plasma nuclear fusion rates

    International Nuclear Information System (INIS)

    Kim, Yeong E.; Zubarev, Alexander L.

    2006-01-01

    We investigate the effect of a generalized particle momentum distribution derived by Galitskii and Yakimets (GY) on nuclear reaction rates in plasma. We derive an approximate semi-analytical formula for nuclear fusion reaction rate between nuclei in a plasma (quantum plasma nuclear fusion; or QPNF). The QPNF formula is applied to calculate deuteron-deuteron fusion rate in a plasma, and the results are compared with the results calculated with the conventional Maxwell-Boltzmann velocity distribution. As an application, we investigate the deuteron-deuteron fusion rate for mobile deuterons in a deuterated metal/alloy. The calculated deuteron-deuteron fusion rates at low energies are enormously enhanced due to the modified tail of the GY's generalized momentum distribution. Our preliminary estimates indicate also that the deuteron-lithium (D+Li) fusion rate and the proton-lithium (p+Li) fusion rate in a metal/alloy at ambient temperatures are also substantially enhanced. (author)

  5. Interplay of Laser-Plasma Interactions and Inertial Fusion Hydrodynamics

    International Nuclear Information System (INIS)

    Strozzi, D. J.; Bailey, D. S.; Michel, P.; Divol, L.; Sepke, S. M.

    2017-01-01

    The effects of laser-plasma interactions (LPI) on the dynamics of inertial confinement fusion hohlraums are investigated in this work via a new approach that self-consistently couples reduced LPI models into radiation-hydrodynamics numerical codes. The interplay between hydrodynamics and LPI—specifically stimulated Raman scatter and crossed-beam energy transfer (CBET)—mostly occurs via momentum and energy deposition into Langmuir and ion acoustic waves. This spatially redistributes energy coupling to the target, which affects the background plasma conditions and thus, modifies laser propagation. In conclusion, this model shows reduced CBET and significant laser energy depletion by Langmuir waves, which reduce the discrepancy between modeling and data from hohlraum experiments on wall x-ray emission and capsule implosion shape.

  6. Microwave Receivers for Fast-Ion Detection in Fusion Plasmas

    DEFF Research Database (Denmark)

    Furtula, Vedran

    for the frequency range from 100 to 110 GHz. In this thesis we follow the path of the radiation from a fusion plasma to the data acquisition unit. Firstly, the scattered radiation passes through the quasi-optical system. Quasi-optical elements required to be installed on the high field side (HFS) on the ITER...... are assessed. For the ITER HFS receiver we have designed and measured the quasioptical components that form a transmission link between the plasma and the radio frequency (RF) electronics. This HFS receiver is required to resolve the near parallel velocity components created by the alpha particles. Secondly...... is the mixer. The conversion loss of the mixer, together with loss in waveguide components and quasi-optic parts, is the main contributor to the noise and thereby degrades the signal to-noise ratio. The architecture of the mixer is a subharmonic type, optimized to be driven by a double local oscillator (LO...

  7. Radiation-magnetohydrodynamics of fusion plasmas on parallel supercomputers

    International Nuclear Information System (INIS)

    Yasar, O.; Moses, G.A.; Tautges, T.J.

    1993-01-01

    A parallel computational model to simulate fusion plasmas in the radiation-magnetohydrodynamics (R-MHD) framework is presented. Plasmas are often treated in a fluid dynamics context (magnetohydrodynamics, MHD), but when the flow field is coupled with the radiation field it falls into a more complex category, radiation magnetohydrodynamics (R-MHD), where the interaction between the flow field and the radiation field is nonlinear. The solution for the radiation field usually dominates the R-MHD computation. To solve for the radiation field, one usually chooses the S N discrete ordinates method (a deterministic method) rather than the Monte Carlo method if the geometry is not complex. The discrete ordinates method on a massively parallel processor (Intel iPSC/860) is implemented. The speedup is 14 for a run on 16 processors and the performance is 3.7 times better than a single CRAY YMP processor implementation. (orig./DG)

  8. Plasma etching to enhance the surface insulating stability of alumina for fusion applications

    Directory of Open Access Journals (Sweden)

    M. Malo

    2016-12-01

    Full Text Available A significant increase in the surface electrical conductivity of alumina, considered one of the most promising insulating materials for numerous applications in fusion devices, has been observed during ion bombardment in vacuum due to oxygen loss by preferential sputtering. Although this is expected to cause serious limitations to insulating components functionality, recent studies showed it is possible to restore the damaged lattice by oxygen reincorporation during thermal treatments in air. These studies also revealed a correlation between conductivity and ion beam induced luminescence, which is being used to monitor surface electrical conductivity degradation and help qualify the post irradiation recovery. Work now carried out for Wesgo alumina considers oxygen implantation and plasma etching as additional methods to improve recovered layer depth and quality. Both conductivity and luminescence results indicate the potential use of plasma etching not only for damage recovery, but also as a pre-treatment to enhance material stability during irradiation.

  9. Radiation control in fusion plasmas by magnetic confinement

    International Nuclear Information System (INIS)

    Dachicourt, R.

    2012-10-01

    The present work addresses two important issues for the industrial use of fusion: plasma radiation control, as a part of the more general power handling issue, and high density tokamak operation. These two issues will be most critical in the demonstration reactor, called DEMO, intermediate step between ITER and a future commercial reactor. For DEMO, the need to radiate a large fraction of the power so as to limit the peak power load on the divertor will be a key constraint. High confinement will have to be combined with high radiated power fraction, and the required level of plasma purity. The main achievement of this thesis is to have shown experimental evidence of the existence of a stable plasma regime meeting the most critical requirements of a DEMO scenario: an electron density up to 40% above the Greenwald value, together with a fraction of radiated power close to 80%, with a good energy confinement and limited dilution. The plasma is additionally heated with ion cyclotron waves in a central electron heating scenario, featuring alpha particle heating. The original observations reported in this work bring highly valuable new pieces of information both to the physics of the tokamak edge layer and to the construction of an 'integrated operational scenario' required to successfully operate fusion devices. In the way for getting high density plasmas, the new observations involve the following topics. First, the formation of a poloidal asymmetry in the edge electron density profile, with a maximum density located close to toroidal pumped limiter. This asymmetry occurs inside the separatrix, with a constant plasma pressure on magnetic surfaces. Secondly, a correlative decrease of the electron temperature in the same edge region. Thirdly, the excellent coupling capabilities of the ICRH waves, up to a central line averaged electron density of 1.4 times the Greenwald density. Fourthly, a poloidally asymmetric edge radiation region, providing the dissipation of 80% of

  10. Self-organized helical equilibria as a new paradigm for ohmically heated fusion plasmas

    Czech Academy of Sciences Publication Activity Database

    Lorenzini, R.; Martines, E.; Piovesan, P.; Terranova, D.; Zanca, P.; Zuin, M.; Alfier, A.; Bonfiglio, D.; Bonomo, F.; Canton, A.; Cappello, S.; Carraro, L.; Cavazzana, R.; Escande, D.F.; Fassina, A.; Franz, P.; Gobbin, M.; Innocente, P.; Marrelli, L.; Pasqualotto, R.; Puiatti, M.E.; Spolaore, M.; Valisa, M.; Vianello, N.; Martin, P.; Apolloni, L.; Adámek, Jiří; Agostini, M.; Annibaldi, S.V.; Antoni, V.; Auriemma, F.; Barana, O.; Baruzzo, M.; Bettini, P.; Bolzonella, T.; Brombin, M.; Brotánková, Jana; Buffa, A.; Buratti, P.; Cavinato, M.; Chapman, B.E.; Chitarin, G.; Dal Bello, S.; De Lorenzi, A.; De Masi, G.; Ferro, A.; Gaio, E.; Gazza, E.; Giudicotti, L.; Gnesotto, F.; Grando, L.; Guazzotto, L.; Guo, S.C.; Igochine, V.; Liu, Y.Q.; Luchetta, A.; Manduchi, G.; Marchiori, G.; Marcuzzi, D.; Martini, S.; McCollam, K.; Milani, F.; Moresco, M.; Novello, L.; Ortolani, S.; Paccagnella, R.; Peruzzo, S.; Piovan, R.; Piron, L.; Pizzimenti, A.; Pomaro, N.; Predebon, I.; Reusch, J.A.; Rostagni, G.; Rubinacci, G.; Sarff, J.S.; Sattin, F.; Scarin, P.; Serianni, G.; Sonato, P.; Spada, E.; Sopplesa, A.; Spagnolo, S.; Spizzo, G.; Taliercio, C.; Toigo, V.; Villone, F.; White, R.B.; Yadikin, D.; Zaccaria, P.; Zamengo, A.; Zaniol, B.; Zanotto, L.; Zilli, E.; Zohm, H.

    2009-01-01

    Roč. 5, č. 8 (2009), s. 570-574 ISSN 1745-2473 Institutional support: RVO:61389021 Keywords : plasma * fusion * ITER * helical equilibrium Subject RIV: BL - Plasma and Gas Discharge Physics Impact factor: 15.491, year: 2009

  11. Invited and contributed papers presented at the 22. EPS conference on controlled fusion and plasma physics

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1995-08-01

    In this report one invited and fifteen contributed papers by researchers of the `Centre de Recherche en Physique des Plasmas`, Lausanne, to the 22. EPS Conference on Controlled Fusion and Plasma Physics are assembled. figs., tabs., refs.

  12. Monitoring and Hardware Management for Critical Fusion Plasma Instrumentation

    Directory of Open Access Journals (Sweden)

    Carvalho Paulo F.

    2018-01-01

    Full Text Available Controlled nuclear fusion aims to obtain energy by particles collision confined inside a nuclear reactor (Tokamak. These ionized particles, heavier isotopes of hydrogen, are the main elements inside of plasma that is kept at high temperatures (millions of Celsius degrees. Due to high temperatures and magnetic confinement, plasma is exposed to several sources of instabilities which require a set of procedures by the control and data acquisition systems throughout fusion experiments processes. Control and data acquisition systems often used in nuclear fusion experiments are based on the Advanced Telecommunication Computer Architecture (AdvancedTCA® standard introduced by the Peripheral Component Interconnect Industrial Manufacturers Group (PICMG®, to meet the demands of telecommunications that require large amount of data (TB transportation at high transfer rates (Gb/s, to ensure high availability including features such as reliability, serviceability and redundancy. For efficient plasma control, systems are required to collect large amounts of data, process it, store for later analysis, make critical decisions in real time and provide status reports either from the experience itself or the electronic instrumentation involved. Moreover, systems should also ensure the correct handling of detected anomalies and identified faults, notify the system operator of occurred events, decisions taken to acknowledge and implemented changes. Therefore, for everything to work in compliance with specifications it is required that the instrumentation includes hardware management and monitoring mechanisms for both hardware and software. These mechanisms should check the system status by reading sensors, manage events, update inventory databases with hardware system components in use and maintenance, store collected information, update firmware and installed software modules, configure and handle alarms to detect possible system failures and prevent emergency

  13. Monitoring and Hardware Management for Critical Fusion Plasma Instrumentation

    Science.gov (United States)

    Carvalho, Paulo F.; Santos, Bruno; Correia, Miguel; Combo, Álvaro M.; Rodrigues, AntÓnio P.; Pereira, Rita C.; Fernandes, Ana; Cruz, Nuno; Sousa, Jorge; Carvalho, Bernardo B.; Batista, AntÓnio J. N.; Correia, Carlos M. B. A.; Gonçalves, Bruno

    2018-01-01

    Controlled nuclear fusion aims to obtain energy by particles collision confined inside a nuclear reactor (Tokamak). These ionized particles, heavier isotopes of hydrogen, are the main elements inside of plasma that is kept at high temperatures (millions of Celsius degrees). Due to high temperatures and magnetic confinement, plasma is exposed to several sources of instabilities which require a set of procedures by the control and data acquisition systems throughout fusion experiments processes. Control and data acquisition systems often used in nuclear fusion experiments are based on the Advanced Telecommunication Computer Architecture (AdvancedTCA®) standard introduced by the Peripheral Component Interconnect Industrial Manufacturers Group (PICMG®), to meet the demands of telecommunications that require large amount of data (TB) transportation at high transfer rates (Gb/s), to ensure high availability including features such as reliability, serviceability and redundancy. For efficient plasma control, systems are required to collect large amounts of data, process it, store for later analysis, make critical decisions in real time and provide status reports either from the experience itself or the electronic instrumentation involved. Moreover, systems should also ensure the correct handling of detected anomalies and identified faults, notify the system operator of occurred events, decisions taken to acknowledge and implemented changes. Therefore, for everything to work in compliance with specifications it is required that the instrumentation includes hardware management and monitoring mechanisms for both hardware and software. These mechanisms should check the system status by reading sensors, manage events, update inventory databases with hardware system components in use and maintenance, store collected information, update firmware and installed software modules, configure and handle alarms to detect possible system failures and prevent emergency scenarios

  14. Fundamentals of plasma physics and controlled fusion. The third edition

    International Nuclear Information System (INIS)

    Miyamoto, Kenro

    2011-06-01

    Primary objective of this lecture note is to provide a basic text for the students to study plasma physics and controlled fusion researches. Secondary objective is to offer a reference book describing analytical methods of plasma physics for the researchers. This was written based on lecture notes for a graduate course and an advanced undergraduate course those have been offered at Department of Physics, Faculty of Science, University of Tokyo. In ch.1 and 2, basic concept of plasma and its characteristics are explained. In ch.3, orbits of ion and electron are described in several magnetic field configurations. Chapter 4 formulates Boltzmann equation of velocity space distribution function, which is the basic relation of plasma physics. From ch.5 to ch.9, plasmas are described as magnetohydrodynamic (MHD) fluid. MHD equation of motion (ch.5), equilibrium (ch.6) and diffusion and confinement time of plasma (ch.7) are described by the fluid model. Chapters 8 and 9 discuss problems of MHD instabilities whether a small perturbation will grow to disrupt the plasma or will damp to a stable state. The basic MHD equation of motion can be derived by taking an appropriate average of Boltzmann equation. This mathematical process is described in appendix A. The derivation of useful energy integral formula of axisymmetric toroidal system and the analysis of high n ballooning mode are described in app. B. From ch.10 to ch.14, plasmas are treated by kinetic theory. This medium, in which waves and perturbations propagate, is generally inhomogeneous and anisotropic. It may absorb or even amplify the wave. Cold plasma model described in ch.10 is applicable when the thermal velocity of plasma particles is much smaller than the phase velocity of wave. Because of its simplicity, the dielectric tensor of cold plasma can be easily derived and the properties of various wave can be discussed in the case of cold plasma. If the refractive index becomes large and the phase velocity of the

  15. Neutron Generation by Laser-Driven Spherically Convergent Plasma Fusion

    Science.gov (United States)

    Ren, G.; Yan, J.; Liu, J.; Lan, K.; Chen, Y. H.; Huo, W. Y.; Fan, Z.; Zhang, X.; Zheng, J.; Chen, Z.; Jiang, W.; Chen, L.; Tang, Q.; Yuan, Z.; Wang, F.; Jiang, S.; Ding, Y.; Zhang, W.; He, X. T.

    2017-04-01

    We investigate a new laser-driven spherically convergent plasma fusion scheme (SCPF) that can produce thermonuclear neutrons stably and efficiently. In the SCPF scheme, laser beams of nanosecond pulse duration and 1 014- 1 015 W /cm2 intensity uniformly irradiate the fuel layer lined inside a spherical hohlraum. The fuel layer is ablated and heated to expand inwards. Eventually, the hot fuel plasmas converge, collide, merge, and stagnate at the central region, converting most of their kinetic energy to internal energy, forming a thermonuclear fusion fireball. With the assumptions of steady ablation and adiabatic expansion, we theoretically predict the neutron yield Yn to be related to the laser energy EL, the hohlraum radius Rh, and the pulse duration τ through a scaling law of Yn∝(EL/Rh1.2τ0.2 )2.5. We have done experiments at the ShengGuangIII-prototype facility to demonstrate the principle of the SCPF scheme. Some important implications are discussed.

  16. Interplay of light and heavy impurities in a fusion plasma

    Energy Technology Data Exchange (ETDEWEB)

    Gaja, Mustafa [IPP, Garching (Germany); Tokar, Mikhail [IEK4, Juelich FZ, Juelich (Germany)

    2016-07-01

    Radiation from impurities eroded from the walls can lead to a broad spectrum of spectacular phenomena in fusion devices An example of such events are breathing oscillations observed in the large helical device (LHD), in long pulse discharges with a stainless steel divertor. They were characterized with oscillations of a period of a second in various plasma parameters. By optimizing magnetic geometry this operation mode, leading to a deteriorate plasma performance, can be avoided. Nonetheless it is of interest and practical importance to understand and firmly predict conditions for breathing phenomenon, in particular, in view of similar impurity environment in W-7 X stellarator. A qualitative explanation for breathing oscillations proposed earlier presumes that they arise due to non-linear synergetic interplay of diverse physical processes. A one-dimensional non-stationary model, describing the generation and transport of main, impurity particles and heat by including the radiation of high-Z (Fe) and low-Z (C and O) impurities is elaborated here. The calculations predict the appearance of oscillations in the relevant range of plasma parameters, reproduce well experimentally observed amplitudes and period of oscillations. It demonstrates that the smaller the fraction of the plasma interaction with a stainless steel surface, the higher the light impurity concentration needed to excite the breathing oscillations. This shows a way to avoid oscillations in future experiments.

  17. Twentyseventh European physical society conference on controlled fusion and plasma physics

    International Nuclear Information System (INIS)

    Igitkhanov, Y.

    2000-01-01

    The twentyseventh European physical society conference on controlled fusion and plasma physics was held in Budapest, 12-16 June 2000. About 10 invited papers were presented, covering a wide range of problems in plasma physics, including confinement and transport issues in fusion devices, astrophysics and industrial application of plasmas. More than 100 papers were presented on plasma theory and experiments from tokamaks and stellarators. Some of the ITER-relevant issues covered are described in this newsletter

  18. Dense Plasma Focus - From Alternative Fusion Source to Versatile High Energy Density Plasma Source for Plasma Nanotechnology

    Science.gov (United States)

    Rawat, R. S.

    2015-03-01

    The dense plasma focus (DPF), a coaxial plasma gun, utilizes pulsed high current electrical discharge to heat and compress the plasma to very high density and temperature with energy densities in the range of 1-10 × 1010 J/m3. The DPF device has always been in the company of several alternative magnetic fusion devices as it produces intense fusion neutrons. Several experiments conducted on many different DPF devices ranging over several order of storage energy have demonstrated that at higher storage energy the neutron production does not follow I4 scaling laws and deteriorate significantly raising concern about the device's capability and relevance for fusion energy. On the other hand, the high energy density pinch plasma in DPF device makes it a multiple radiation source of ions, electron, soft and hard x-rays, and neutrons, making it useful for several applications in many different fields such as lithography, radiography, imaging, activation analysis, radioisotopes production etc. Being a source of hot dense plasma, strong shockwave, intense energetic beams and radiation, etc, the DPF device, additionally, shows tremendous potential for applications in plasma nanoscience and plasma nanotechnology. In the present paper, the key features of plasma focus device are critically discussed to understand the novelties and opportunities that this device offers in processing and synthesis of nanophase materials using, both, the top-down and bottom-up approach. The results of recent key experimental investigations performed on (i) the processing and modification of bulk target substrates for phase change, surface reconstruction and nanostructurization, (ii) the nanostructurization of PLD grown magnetic thin films, and (iii) direct synthesis of nanostructured (nanowire, nanosheets and nanoflowers) materials using anode target material ablation, ablated plasma and background reactive gas based synthesis and purely gas phase synthesis of various different types of

  19. Dense Plasma Focus - From Alternative Fusion Source to Versatile High Energy Density Plasma Source for Plasma Nanotechnology

    International Nuclear Information System (INIS)

    Rawat, R S

    2015-01-01

    The dense plasma focus (DPF), a coaxial plasma gun, utilizes pulsed high current electrical discharge to heat and compress the plasma to very high density and temperature with energy densities in the range of 1-10 × 10 10 J/m 3 . The DPF device has always been in the company of several alternative magnetic fusion devices as it produces intense fusion neutrons. Several experiments conducted on many different DPF devices ranging over several order of storage energy have demonstrated that at higher storage energy the neutron production does not follow I 4 scaling laws and deteriorate significantly raising concern about the device's capability and relevance for fusion energy. On the other hand, the high energy density pinch plasma in DPF device makes it a multiple radiation source of ions, electron, soft and hard x-rays, and neutrons, making it useful for several applications in many different fields such as lithography, radiography, imaging, activation analysis, radioisotopes production etc. Being a source of hot dense plasma, strong shockwave, intense energetic beams and radiation, etc, the DPF device, additionally, shows tremendous potential for applications in plasma nanoscience and plasma nanotechnology. In the present paper, the key features of plasma focus device are critically discussed to understand the novelties and opportunities that this device offers in processing and synthesis of nanophase materials using, both, the top-down and bottom-up approach. The results of recent key experimental investigations performed on (i) the processing and modification of bulk target substrates for phase change, surface reconstruction and nanostructurization, (ii) the nanostructurization of PLD grown magnetic thin films, and (iii) direct synthesis of nanostructured (nanowire, nanosheets and nanoflowers) materials using anode target material ablation, ablated plasma and background reactive gas based synthesis and purely gas phase synthesis of various different types of

  20. The long way to steady state fusion plasmas - the superconducting stellarator device Wendelstein 7-X

    CERN Multimedia

    CERN. Geneva

    2016-01-01

    The stable generation of high temperature Hydrogen plasmas (ion and electron temperature in the range 10-20 keV) is the basis for the use of nuclear fusion to generate heat and thereby electric power. The most promising path is to use strong, toroidal, twisted magnetic fields to confine the electrically charged plasma particles in order to avoid heat losses to the cold, solid wall elements. Two magnetic confinement concepts have been proven to be most suitable: (a) the tokamak and (b) the stellarator. The stellarator creates the magnetic field by external coils only, the tokamak by combining the externally created field with the magnetic field generated by a strong current in the plasma. “Wendelstein 7-X” is the name of a large superconducting stellarator that went successfully into operation after 15 years of construction. With 30 m3 plasma volume, 3 T magnetic field on axis, and 10 MW micro wave heating power, Hydrogen plasmas are generated that allow one to establish a scientific basis for the extrapol...

  1. Plasma current sustained by fusion charged particles in a field reversed configuration

    International Nuclear Information System (INIS)

    Berk, H.L.; Momota, H.; Tajima, T.

    1987-04-01

    The distribution of energetic charged particles generated by thermonuclear fusion reactions in a field reversed configuration (FRC) are studied analytically and numerically. A fraction of the charged fusion products escapes directly while the others are trapped to form a directed particle flow parallel to the plasma current. It is shown that the resultant current density produced by these fusion charged particles can be comparable to background plasma current density that produces the original field reversed configuration in a D- 3 He reactor. Self-consistent equilibria arising from the currents of the background plasma and proton fusion products are constructed where the Larmor radius of the fusion product is of arbitrary size. Reactor relevant parameters are examined, such as how the fusion reactivity rate varies as a result of supporting the pressure associated with the fusion products. We also model the synchrotron emission from various pressure profiles and quantitatively show how synchrotron losses vary with different pressure profiles in an FRC configuration

  2. Fusion plasma theory grant: Task 1, Magnetic confinement fusion plasma theory

    International Nuclear Information System (INIS)

    Callen, J.D.

    1989-07-01

    The research performed under this grant during the current year has concentrated on key tokamak plasma confinement and heating theory issues: further development of neoclassical MHD; development of a new fluid/kinetic hybrid model; energy confinement degradation due to macroscopic phenomena in tokamaks; and some other topics (magnetics analysis, coherent structures, presheath structure). Progress and publications in these areas are briefly summarized in this report. 20 refs

  3. 1991 US-Japan workshop on Nuclear Fusion in Dense Plasmas

    International Nuclear Information System (INIS)

    Ichimaru, S.; Tajima, T.

    1991-10-01

    The scientific areas covered at the Workshop may be classified into the following subfields: (1) basic theory of dense plasma physics and its interface with atomic physics and nuclear physics; (2) physics of dense z-pinches, ICF plasmas etc; (3) stellar interior plasmas; (4) cold fusion; and (5) other dense plasmas

  4. Atomic and plasma-material interaction data for fusion. Vol.1

    International Nuclear Information System (INIS)

    1991-01-01

    The International Atomic Energy Agency, through its Atomic and Molecular Data Unit, coordinates a wide spectrum of programmes for the compilation, evaluation, and generation of atomic, molecular, and plasma-wall interaction data for fusion research. The present, first, volume of Atomic and Plasma-Material Interaction Data for Fusion, contains extended versions of the reviews presented at the IAEA Advisory Group Meeting on Particle-Surface Interaction Data for Fusion, held 19-21 April 1989 at the IAEA Headquarters in Vienna, The plasma-wall interaction processes covered here are those considered most important for the operational performance of magnetic confinement fusion reactors. In addition to processes due to particle impact under normal operation, plasma-wall interaction effects due to off-normal plasma events (disruptions, electron runaway bombardment) are covered, and a summary of the status of data information on these processes is given from the point of view of magnetic fusion reactor design. Refs, figs and tabs

  5. Plasma behavior and plasma-wall interaction in magnetic fusion divices

    International Nuclear Information System (INIS)

    Ohtsuka, Hideo

    1984-10-01

    To study the fundamental behavior of plasma in magnetic field is the main subject in the early stage of the magnetic fusion research. At the next stage, it is necessary to overcome some actual problems in order to attain reactor grade plasmas. One of them is to control impurities in the plasma. In these points of view, we carried out several experiments or theoretical analyses. Firstly, anomalous loss mechanisms in magnetic field were investigated in a toroidal multipole device JFT-1 and the role of motions of charged particles in the magnetic field was exhibited. Various measurements of plasma in the scrape-off layer were made in a divertor tokamak JFT-2a and in an ordinary tokamak JFT-2. The former study demonstrated the first successful divertor operation of the tokamak device and the latter one clarified the mechanism of arcing on the tokamak first wall. As to arcing, a new theory which describes the retrograde motion, the well known strange motion of arcs in a magnetic field, was proposed. Good agreement with the experimental results was shown. Finally, by considering a zero-dimensional sputtering model a self-consistent relation between light and metal impurities in tokamak plasmas was obtained. It was shown that the relation well describes some fundamental aspects of the plasma-wall interaction. As a conclusion, the importance of simple behavior of charged particles in magnetic fields was pointed out not only for the plasma confinement but also for the plasma-wall interaction. (author)

  6. Relevance, Realization and stability of a cold layer at the plasma edge for fusion reactors

    International Nuclear Information System (INIS)

    1990-09-01

    The workshop was dedicated to the realization and stability of a cold layer at the plasma edge for fusion reactors. The subjects of the communications presented were: impurity transport, and control, plasma boundary layers, power balance, radiation control and modifications, limiter discharges, tokamak density limit, Asdex divertor discharges, thermal stability of a radiating diverted plasma, plasma stability, auxiliary heating in Textor, detached plasma in Tore Supra, poloidal divertor tokamak, radiation cooling, neutral-particle transport, plasma scrape-off layer, edge turbulence

  7. Collective phenomena with energetic particles in fusion plasmas

    International Nuclear Information System (INIS)

    Breizman, B.N.; Berk, H.L.; Candy, J.

    2001-01-01

    Recent progress in the theory of collective modes driven by energetic particles, as well as interpretations of fast particle effects observed in fusion-related experiments, are described. New developments in linear theory include: (a) Alfven-mode frequency gap widening due to energetic trapped ions, (b) interpretation of JET results for plasma pressure effect on TAE modes, and (c) ''counter'' propagation of TAE modes due to trapped fast ion anisotropy. The new nonlinear results are: (a) theoretical explanation for the pitchfork splitting effect observed in TAE experiments on JET, (b) existence of coherent structures with strong frequency chirping due to kinetic instability, (c) self-consistent nonlinear theory for fishbone instabilities, and (d) intermittent quasilinear diffusion model for anomalous fast particle losses. (author)

  8. Collective phenomena with energetic particles in fusion plasmas

    International Nuclear Information System (INIS)

    Breizman, B.N.; Berk, H.L.; Candy, J.

    1999-01-01

    Recent progress in the theory of collective modes driven by energetic particles, as well as interpretations of fast particle effects observed in fusion-related experiments, are described. New developments in linear theory include: (a) Alfven-mode frequency gap widening due to energetic trapped ions, (b) interpretation of JET results for plasma pressure effect on TAE modes, and (c) 'counter' propagation of TAE modes due to trapped fast ion anisotropy. The new nonlinear results are: (a) theoretical explanation for the pitchfork splitting effect observed in TAE experiments on JET, (b) existence of coherent structures with strong frequency chirping due to kinetic instability, (c) self-consistent nonlinear theory for fishbone instabilities, and (d) intermittent quasilinear diffusion model for anomalous fast particle losses. (author)

  9. High quality actively cooled plasma facing components for fusion

    International Nuclear Information System (INIS)

    Nygren, R.

    1993-01-01

    This paper interweaves some suggestions for developing actively-cooled PFCs (plasma facing components) for future fusion devices with supporting examples taken from the design, fabrication and operation of Tore Supra's Phase III Outboard Pump Limiter (OPL). This actively-cooled midplane limiter, designed for heat and particle removal during long pulse operation, has been operated in essentially thermally steady state conditions. From experience with testing to identify braze flaws in the OPL, recommendations are made to analyze the impact of joining flaws on thermal-hydraulic performance of PFCs and to validate a method of inspection for such flaws early in the design development. Capability for extensive in-service monitoring of future PFCs is also recommended and the extensive calorimetry and IR thermography used to confirm and update safe operating limits for power handling of the OPL are reviewed

  10. High quality actively cooled plasma-facing components for fusion

    International Nuclear Information System (INIS)

    Nygren, R.E.

    1995-01-01

    This paper interweaves some suggestions for developing actively cooled plasma-facing components (PFCs) for future fusion devices, with supporting examples taken from the design, fabrication and operation of Tore Supra's Phase III outboard pump limiter (OPL). This actively cooled midplane limiter, designed for heat and particle removal during long-pulse operation, has been operated under essentially thermally steady state conditions. Testing to identify braze flaws, analysis of the impact of joining flaws on the thermal-hydraulic performance of the OPL, and the extensive calorimetry and IR thermography used to confirm and update safe operating limits for power handling of the OPL are reviewed. This experience suggests that, for PFCs in future fusion devices, flaw-tolerant designs are possible; analyses of the impacts of flaws on performance can provide criteria for quality assurance; and validating appropriate methods of inspection for such flaws early in the design development of PFCs is prudent. The need for in-service monitoring is also discussed. (orig.)

  11. Inhibition of HIV-1 endocytosis allows lipid mixing at the plasma membrane, but not complete fusion

    Directory of Open Access Journals (Sweden)

    de la Vega Michelle

    2011-12-01

    Full Text Available Abstract Background We recently provided evidence that HIV-1 enters HeLa-derived TZM-bl and lymphoid CEMss cells by fusing with endosomes, whereas its fusion with the plasma membrane does not proceed beyond the lipid mixing step. The mechanism of restriction of HIV-1 fusion at the cell surface and/or the factors that aid the virus entry from endosomes remain unclear. Results We examined HIV-1 fusion with a panel of target cells lines and with primary CD4+ T cells. Kinetic measurements of fusion combined with time-resolved imaging of single viruses further reinforced the notion that HIV-1 enters the cells via endocytosis and fusion with endosomes. Furthermore, we attempted to deliberately redirect virus fusion to the plasma membrane, using two experimental strategies. First, the fusion reaction was synchronized by pre-incubating the viruses with cells at reduced temperature to allow CD4 and coreceptors engagement, but not the virus uptake or fusion. Subsequent shift to a physiological temperature triggered accelerated virus uptake followed by entry from endosomes, but did not permit fusion at the cell surface. Second, blocking HIV-1 endocytosis by a small-molecule dynamin inhibitor, dynasore, resulted in transfer of viral lipids to the plasma membrane without any detectable release of the viral content into the cytosol. We also found that a higher concentration of dynasore is required to block the HIV-endosome fusion compared to virus internalization. Conclusions Our results further support the notion that HIV-1 enters disparate cell types through fusion with endosomes. The block of HIV-1 fusion with the plasma membrane at a post-lipid mixing stage shows that this membrane is not conducive to fusion pore formation and/or enlargement. The ability of dynasore to interfere with the virus-endosome fusion suggests that dynamin could be involved in two distinct steps of HIV-1 entry - endocytosis and fusion within intracellular compartments.

  12. Atomic and plasma-material interaction data for fusion. V. 5

    International Nuclear Information System (INIS)

    1994-01-01

    Volume 5 of the supplements on ''atomic and plasma-material interaction data for fusion'' to the journal ''Nuclear Fusion'' is devoted to a critical assessment of the physical and thermo-mechanical properties of presently considered candidate plasma-facing and structural materials for next-generation thermonuclear fusion devices. It contains 9 papers. The subjects are: (i) requirements and selection criteria for plasma-facing materials and components in the ITER EDA (Engineering Design Activities) design; (ii) thermomechanical properties of Beryllium; (iii) material properties data for fusion reactor plasma-facing carbon-carbon composites; (iv) high-Z candidate plasma facing materials; (v) recommended property data for Molybdenum, Niobium and Vanadium alloys; (vi) copper alloys for high heat flux structure applications; (vii) erosion of plasma-facing materials during a tokamak disruption; (viii) runaway electron effects; and (ix) data bases for thermo-hydrodynamic coupling with coolants. Refs, figs, tabs

  13. Extended MHD modeling of nonlinear instabilities in fusion and space plasmas

    Energy Technology Data Exchange (ETDEWEB)

    Germaschewski, Kai [Univ. of New Hampshire, Durham, NH (United States)

    2017-11-15

    A number of different sub-projects where pursued within this DOE early career project. The primary focus was on using fully nonlinear, curvilinear, extended MHD simulations of instabilities with applications to fusion and space plasmas. In particular, we performed comprehensive studies of the dynamics of the double tearing mode in different regimes and confi gurations, using Cartesian and cyclindrical geometry and investigating both linear and non-linear dynamics. In addition to traditional extended MHD involving Hall term and electron pressure gradient, we also employed a new multi-fluid moment model, which shows great promise to incorporate kinetic effects, in particular off-diagonal elements of the pressure tensor, in a fluid model, which is naturally computationally much cheaper than fully kinetic particle or Vlasov simulations. We used our Vlasov code for detailed studies of how weak collisions effect plasma echos. In addition, we have played an important supporting role working with the PPPL theory group around Will Fox and Amitava Bhattacharjee on providing simulation support for HED plasma experiments performed at high-powered laser facilities like OMEGA-EP in Rochester, NY. This project has support a great number of computational advances in our fluid and kinetic plasma models, and has been crucial to winning multiple INCITE computer time awards that supported our computational modeling.

  14. A National Collaboratory to Advance the Science of High Temperature Plasma Physics for Magnetic Fusion

    International Nuclear Information System (INIS)

    Schissel, D.P.; Abla, G.; Burruss, J.R.; Feibush, E.; Fredian, T.W.; Goode, M.M.; Greenwald, M.J.; Keahey, K.; Leggett, T.; Li, K.; McCune, D.C.; Papka, M.E.; Randerson, L.; Sanderson, A.; Stillerman, J.; Thompson, M.R.; Uram, T.; Wallace, G.

    2006-01-01

    portion of national program efforts are organized around coordinated efforts to develop promising operational scenarios. Substantial efforts to develop integrated plasma modeling codes are also underway in the U.S., Europe and Japan. As a result of the highly collaborative nature of FES research, the community is facing new and unique challenges. While FES has a significant track record for developing and exploiting remote collaborations, with such large investments at stake, there is a clear need to improve the integration and reach of available tools. The NFC Project was initiated to address these challenges by creating and deploying collaborative software tools. The original objective of the NFC project was to develop and deploy a national FES 'Grid' (FusionGrid) that would be a system for secure sharing of computation, visualization, and data resources over the Internet. The goal of FusionGrid was to allow scientists at remote sites to participate as fully in experiments and computational activities as if they were working on site thereby creating a unified virtual organization of the geographically dispersed U.S. fusion community. The vision for FusionGrid was that experimental and simulation data, computer codes, analysis routines, visualization tools, and remote collaboration tools are to be thought of as network services. In this model, an application service provider (ASP) provides and maintains software resources as well as the necessary hardware resources. The project would create a robust, user-friendly collaborative software environment and make it available to the US FES community. This Grid's resources would be protected by a shared security infrastructure including strong authentication to identify users and authorization to allow stakeholders to control their own resources. In this environment, access to services is stressed rather than data or software portability.

  15. Plasma facing materials and components for future fusion devices - development, characterization and performance under fusion specific loading conditions

    Energy Technology Data Exchange (ETDEWEB)

    Linke, J. [Forschungszentrum Juelich (Germany). Inst. fuer Plasmaphysik

    2006-04-15

    The plasma exposed components in existing and future fusion devices are strongly affected by the plasma material interaction processes. These mechanisms have a strong influence on the plasma performance; in addition they have major impact on the lifetime of the plasma facing armour and the joining interface between the plasma facing material (PFM) and the heat sink. Besides physical and chemical sputtering processes, high heat quasi-stationary fluxes during normal and intense thermal transients are of serious concern for the engineers who develop reliable wall components. In addition, the material and component degradation due to intense fluxes of energetic neutrons is another critical issue in D-T-burning fusion devices which requires extensive RandD. This paper presents an overview on the materials development and joining, the testing of PFMs and components, and the analysis of the neutron irradiation induced degradation.

  16. Plasma facing materials and components for future fusion devices - development, characterization and performance under fusion specific loading conditions

    International Nuclear Information System (INIS)

    Linke, J.

    2006-01-01

    The plasma exposed components in existing and future fusion devices are strongly affected by the plasma material interaction processes. These mechanisms have a strong influence on the plasma performance; in addition they have major impact on the lifetime of the plasma facing armour and the joining interface between the plasma facing material (PFM) and the heat sink. Besides physical and chemical sputtering processes, high heat quasi-stationary fluxes during normal and intense thermal transients are of serious concern for the engineers who develop reliable wall components. In addition, the material and component degradation due to intense fluxes of energetic neutrons is another critical issue in D-T-burning fusion devices which requires extensive RandD. This paper presents an overview on the materials development and joining, the testing of PFMs and components, and the analysis of the neutron irradiation induced degradation

  17. Plasma facing materials and components for future fusion devices—development, characterization and performance under fusion specific loading conditions

    Science.gov (United States)

    Linke, J.

    2006-04-01

    The plasma exposed components in existing and future fusion devices are strongly affected by the plasma material interaction processes. These mechanisms have a strong influence on the plasma performance; in addition they have major impact on the lifetime of the plasma facing armour and the joining interface between the plasma facing material (PFM) and the heat sink. Besides physical and chemical sputtering processes, high heat quasi-stationary fluxes during normal and intense thermal transients are of serious concern for the engineers who develop reliable wall components. In addition, the material and component degradation due to intense fluxes of energetic neutrons is another critical issue in D-T-burning fusion devices which requires extensive R&D. This paper presents an overview on the materials development and joining, the testing of PFMs and components, and the analysis of the neutron irradiation induced degradation.

  18. Analysis of noble gas recycling at a fusion plasma divertor

    International Nuclear Information System (INIS)

    Brooks, J.N.

    1996-01-01

    Near-surface recycling of neon and argon atoms and ions at a divertor has been studied using impurity transport and surface interaction codes. A fixed background deuterium endash tritium plasma model is used corresponding to the International Thermonuclear Experimental Reactor (ITER) [ITER EDA Agreement and Protocol 2, ITER EDA Documentation Series No. 5 (International Atomic Energy Agency, Vienna, 1994)] radiative plasma conditions (T e ≤10 eV). The noble gas transport depends critically on the divertor surface material. For low-Z materials (Be and C) both neon and argon recycle many (e.g., ∼100) times before leaving the near-surface region. This is also true for an argon on tungsten combination. For neon on tungsten, however, there is low recycling. These variations are due to differences in particle and energy reflection coefficients, mass, and ionization rates. In some cases a high flux of recycling atoms is ionized within the magnetic sheath and this can change local sheath parameters. Due to inhibited backflow, high recycling, and possibly high sputtering, noble gas seeding (for purposes of enhancing radiation) may be incompatible with Be or C surfaces, for fusion reactor conditions. On the other hand, neon use appears compatible with tungsten. copyright 1996 American Institute of Physics

  19. X-ray diodes for laser fusion plasma diagnostics

    International Nuclear Information System (INIS)

    Day, R.H.; Lee, P.; Saloman, E.B.; Nagel, D.J.

    1981-02-01

    Photodiodes with x-ray sensitive photocathodes are commonly used as broadband x-ray detectors in fusion plasma diagnostics. We have measured the risetime of the detector system and have measured the quantum efficiency between 1 to 500 A of numerous photocathode materials of practical interest. The materials studied include aluminum, copper, nickel, gold, three forms of carbon, chromium, and cesium iodide. The results of the measurements are compared with Henke's semiempirical model of photoyield. We have studied the effects of long-term cathode aging and use as a plasma diagnostic on cathode quantum efficiency. In addition, we have measured the x-ray mass-absorption coefficient of several ultrasoft x-ray windows in energy regions where data were unavailable. Windows studied were made of aluminum, Formvar, polypropylene, and Kimfoil. Measurements between 1 to 50 A were performed with the Los Alamos Scientific Laboratory's low-energy x-ray calibration facility, and the measurements between 50 to 550 A were performed at the National Bureau of Standard's synchrotron ultraviolet radiation facility

  20. Microwave receivers for fast-ion detection in fusion plasmas

    International Nuclear Information System (INIS)

    Furtula, V.

    2012-02-01

    The main objectives of this thesis are to determine fundamental properties of a millimeter wave radiometer used to detect radiation associated with dynamics of fast ions and to investigate possibilities for improvements and new designs. The detection of fast ions is based on a principle called collective Thomson scattering (CTS). The Danish CTS group has been involved in fusion plasma experiments for more than 10 years and the future plans will most probably include the International Thermonuclear Experimental Reactor (ITER). Current CTS systems designed by the Danish group are specified for the frequency range from 100 to 110 GHz. In this thesis we follow the path of the radiation from a fusion plasma to the data acquisition unit. Firstly, the scattered radiation passes through the quasi-optical system. Quasi-optical elements required to be installed on the high field side (HFS) on the ITER are assessed. For the ITER HFS receiver we have designed and measured the quasi-optical components that form a transmission link between the plasma and the radio frequency (RF) electronics. This HFS receiver is required to resolve the near parallel velocity components created by the alpha particles. Secondly, the radiation will encounter the RF part. This part is not yet designed for ITER, but instead the solution is addressed to the CTS receiver installed at ASDEX Upgrade (AUG).We have put effort to thoroughly examine and evaluate the performance of the receiver components and the receiver as an assembled unit. We have measured and analyzed all the receiver components starting from the two notch filters to the fifty square-law detector diodes. The receiver sensitivity is calculated from the system measurements and compared with the expected sensitivity based on the individual component measurements. Besides the system considerations we have also studied improvements of two critical components of the receiver. The first component is the notch filter, which is needed to block

  1. Plasma Wall Interaction Phenomena on Tungsten Armour Materials for Fusion Applications

    International Nuclear Information System (INIS)

    Uytdenhouwen, I.; Massaut, V.; Linke, J.; Van Oost, G.

    2008-01-01

    One of the most attractive future complements to present energy sources is nuclear fusion. A large progress was made throughout the last decade from both the physical as the technological area leading to the construction of the ITER machine. One of the key issues that recently received a large interest at international level is focused on the Plasma Wall Interaction (PWI). One of the promising Plasma Facing Materials (PFM) are Tungsten (W) and Tungsten alloys. However, despite the worldwide use and industrial availability of W, the database of physical and mechanical properties is very limited. Especially after fusion relevant neutron irradiation and PWI phenomena, most of the properties are still unknown. The plasma fuel consists out of deuterium (D) and tritium (T). Tritium is radio-active and therefore an issue from the safety point of view. During steady-state plasma operation of future fusion power plants, the PFM need to extract a power density of ∼10-20 MW/m 2 . On top of this heat, transient events will deposit an additional non-negligible amount of energy (Disruptions, Vertical Displacement Events, Edge Localized Modes) during short durations. These severe heat loads cause cracking and even melting of the surface resulting in a reduced lifetime and the creation of dust. A contribution to the understanding of cracking phenomena under the severe thermal loads is described as well as the properties degradation under neutron irradiation. Several W grades were irradiated in the BR2 reactor (SCK.CEN) and the thermal loads were simulated with the electron-beam facility JUDITH (FZJ). Since knowledge should be gained about the Tritium retention in the PFM for safety and licensing reasons, a unique test facility at SCK.CEN is being set-up. The plasmatron VISION-I will simulate steady state plasmas for Tritium retention studies. The formation of surface cracks and dust, the initial porosity, neutron induced traps, re-deposited material - change the Tritium

  2. Plasma Wall Interaction Phenomena on Tungsten Armour Materials for Fusion Applications

    Energy Technology Data Exchange (ETDEWEB)

    Uytdenhouwen, I. [SCK.CEN - The Belgian Nuclear Research Centre, Institute for Nuclear Materials Science, Boeretang 200, 2400 Mol (Belgium); Forschungszentrum Juelich GmbH, EURATOM-association, D-52425 Juelich (Germany); Department of Applied Physics, Ghent University, Rozier 44, 9000 Ghent (Belgium); Massaut, V. [Department of Applied Physics, Ghent University, Rozier 44, 9000 Ghent (Belgium); Linke, J. [Forschungszentrum Juelich GmbH, EURATOM-association, D-52425 Juelich (Germany); Van Oost, G. [Department of Applied Physics, Ghent University, Rozier 44, 9000 Ghent (Belgium)

    2008-07-01

    One of the most attractive future complements to present energy sources is nuclear fusion. A large progress was made throughout the last decade from both the physical as the technological area leading to the construction of the ITER machine. One of the key issues that recently received a large interest at international level is focused on the Plasma Wall Interaction (PWI). One of the promising Plasma Facing Materials (PFM) are Tungsten (W) and Tungsten alloys. However, despite the worldwide use and industrial availability of W, the database of physical and mechanical properties is very limited. Especially after fusion relevant neutron irradiation and PWI phenomena, most of the properties are still unknown. The plasma fuel consists out of deuterium (D) and tritium (T). Tritium is radio-active and therefore an issue from the safety point of view. During steady-state plasma operation of future fusion power plants, the PFM need to extract a power density of {approx}10-20 MW/m{sup 2}. On top of this heat, transient events will deposit an additional non-negligible amount of energy (Disruptions, Vertical Displacement Events, Edge Localized Modes) during short durations. These severe heat loads cause cracking and even melting of the surface resulting in a reduced lifetime and the creation of dust. A contribution to the understanding of cracking phenomena under the severe thermal loads is described as well as the properties degradation under neutron irradiation. Several W grades were irradiated in the BR2 reactor (SCK.CEN) and the thermal loads were simulated with the electron-beam facility JUDITH (FZJ). Since knowledge should be gained about the Tritium retention in the PFM for safety and licensing reasons, a unique test facility at SCK.CEN is being set-up. The plasmatron VISION-I will simulate steady state plasmas for Tritium retention studies. The formation of surface cracks and dust, the initial porosity, neutron induced traps, re-deposited material - change the Tritium

  3. Technological issues of ion cyclotron heating of fusion plasmas

    International Nuclear Information System (INIS)

    Hwang, D.Q.; Fortgang, C.M.

    1985-01-01

    With the recent promising results of plasma heating using electromagnetic waves (EM waves) in the ion cyclotron range of frequency (ICRF) on the Princeton Large Torus (PLT) tokamak the feasibility of employing ICRF heating to a reactor-like magnetic confinement device is increasing. The high power ICRF experiments funded on JET (Joint European Torus in England) and JT-60 (in Japan) will have rf source power in the range of 10-30 MW. The time scale for the duration of the RF pulse will range from seconds up to steady-state. The development of new RF components that can transmit and launch such high power, long pulse length, EM waves in a plasma environment is a major technological task. In general, the technology issues may be divided into two categories. The first category concerns the region where the plasma comes in contact with the wave launchers. The problems here are dominated by plasmamaterial interaction, heat deposition by the plasma onto the wave launcher, and erosion of the launcher material. It is necessary to minimize the heat deposition from the plasma, the losses of the RF wave energy in the structure, and to prevent sputtering of the antenna components. A solution involves a combined design using special materials and optimal shaping of the Faraday shield (the electrostatic shields which can be used both for an EM wave polarization adjustment and as a particle shield for the launcher). Recent studies by PPPL and McDonnell Douglas Corp. on the Faraday shield designs will be discussed. The second important area where technology development will be necessary is the transmission of high power RF waves through a gas/vacuum interface region. In the past, the vacuum feedthrough has been the bottle neck which prevented high power operation of the PLT antenna

  4. Self-organization observed in either fusion or strongly coupled plasmas

    International Nuclear Information System (INIS)

    Himura, Haruhiko; Sanpei, Akio

    2011-01-01

    If self-organization happens in the fusion plasma, the plasma alters its shape by weakening the confining magnetic field. The self-organized plasma is stable and robust, so its configuration is conserved even during transport in asymmetric magnetic fields. The self-organization of the plasma is driven by an electrostatic potential. Examples of the plasma that has such strong potential are non-neutral plasmas of pure ions or electrons and dusty plasmas. In the present paper, characteristic phenomena of strongly coupled plasmas such as particle aggregation and formation of the ordered structure are discussed. (T.I.)

  5. Influence of collective nonideal shielding on fusion reaction in partially ionized classical nonideal plasmas

    Science.gov (United States)

    Lee, Myoung-Jae; Jung, Young-Dae

    2017-04-01

    The collective nonideal effects on the nuclear fusion reaction process are investigated in partially ionized classical nonideal hydrogen plasmas. The effective pseudopotential model taking into account the collective and plasma shielding effects is applied to describe the interaction potential in nonideal plasmas. The analytic expressions of the Sommerfeld parameter, the fusion penetration factor, and the cross section for the nuclear fusion reaction in nonideal plasmas are obtained as functions of the nonideality parameter, Debye length, and relative kinetic energy. It is found that the Sommerfeld parameter is suppressed due to the influence of collective nonideal shielding. However, the collective nonideal shielding is found to enhance the fusion penetration factor in partially ionized classical nonideal plasmas. It is also found that the fusion penetration factors in nonideal plasmas represented by the pseudopotential model are always greater than those in ideal plasmas represented by the Debye-Hückel model. In addition, it is shown that the collective nonideal shielding effect on the fusion penetration factor decreases with an increase of the kinetic energy.

  6. Trends of plasma physics and nuclear fusion research life cycle and research effort curve

    International Nuclear Information System (INIS)

    Ohe, Takeru; Kanada, Yasumasa; Momota, Hiromu; Ichikawa, Y.H.

    1979-05-01

    This paper presents a quantitative analysis of research trends in the fields of plasma physics and nuclear fusion. This analysis is based on information retrieval from available data bases such as INSPEC tapes. The results indicate that plasma physics research is now in the maturation phase of its life cycle, and that nuclear fusion research is in its growth phase. This paper indicates that there is a correlation between the number of accumulated papers in the fields of plasma physics and nuclear fusion and the experimentally attained values of the plasma ignition parameter ntT. Using this correlation ''research effort curve'', we forecast that the scientific feasibility of controlled fusion using magnetic confinement systems will be proved around 1983. (author)

  7. A Tutorial on Basic Principles of Microwave Reflectometry Applied to Fluctuation Measurements in Fusion Plasmas

    International Nuclear Information System (INIS)

    Nazikian, R.; Kramer, G.J.; Valeo, E.

    2001-01-01

    Microwave reflectometry is now routinely used for probing the structure of magnetohydrodynamic and turbulent fluctuations in fusion plasmas. Conditions specific to the core of tokamak plasmas, such as small amplitude of density irregularities and the uniformity of the background plasma, have enabled progress in the quantitative interpretation of reflectometer signals. In particular, the extent of applicability of the 1-D [one-dimensional] geometric optics description of the reflected field is investigated by direct comparison to 1-D full wave analysis. Significant advances in laboratory experiments are discussed which are paving the way towards a thorough understanding of this important measurement technique. Data is presented from the Tokamak Fusion Test Reactor [R. Hawryluk, Plasma Physics and Controlled Fusion 33 (1991) 1509] identifying the validity of the geometric optics description of the scattered field and demonstrating the feasibility of imaging turbulent fluctuations in fusion scale devices

  8. Contributions to the 7th International Conference on plasma surface interactions in controlled fusion devices

    International Nuclear Information System (INIS)

    1986-01-01

    The report contains three papers presented in the 7th International Conference on plasma surface interactions in controlled fusion devices held in Princeton (USA) 5-9 May 1986, all referred to the FT Tokamak

  9. Present status on atomic and molecular data relevant to fusion plasma diagnostics and modeling

    International Nuclear Information System (INIS)

    Tawara, H.

    1997-01-01

    This issue is the collection of the paper presented status on atomic and molecular data relevant to fusion plasma diagnostics and modeling. The 10 of the presented papers are indexed individually. (J.P.N.)

  10. Understanding L-H transition in tokamak fusion plasmas

    Science.gov (United States)

    Xu, Guosheng; Wu, Xingquan

    2017-03-01

    This paper reviews the current state of understanding of the L-H transition phenomenon in tokamak plasmas with a focus on two central issues: (a) the mechanism for turbulence quick suppression at the L-H transition; (b) the mechanism for subsequent generation of sheared flow. We briefly review recent advances in the understanding of the fast suppression of edge turbulence across the L-H transition. We uncover a comprehensive physical picture of the L-H transition by piecing together a number of recent experimental observations and insights obtained from 1D and 2D simulation models. Different roles played by diamagnetic mean flow, neoclassical-driven mean flow, turbulence-driven mean flow, and turbulence-driven zonal flows are discussed and clarified. It is found that the L-H transition occurs spontaneously mediated by a shift in the radial wavenumber spectrum of edge turbulence, which provides a critical evidence for the theory of turbulence quench by the flow shear. Remaining questions and some key directions for future investigations are proposed. This work was supported by National Magnetic Confinement Fusion Science Program of China under Contracts No. 2015GB101000, No. 2013GB106000, and No. 2013GB107000 and National Natural Science Foundation of China under Contracts No. 11575235 and No. 11422546.

  11. Promising Metabolite Profiles in the Plasma and CSF of Early Clinical Parkinson's Disease

    Directory of Open Access Journals (Sweden)

    Daniel Stoessel

    2018-03-01

    Full Text Available Parkinson's disease (PD shows high heterogeneity with regard to the underlying molecular pathogenesis involving multiple pathways and mechanisms. Diagnosis is still challenging and rests entirely on clinical features. Thus, there is an urgent need for robust diagnostic biofluid markers. Untargeted metabolomics allows establishing low-molecular compound biomarkers in a wide range of complex diseases by the measurement of various molecular classes in biofluids such as blood plasma, serum, and cerebrospinal fluid (CSF. Here, we applied untargeted high-resolution mass spectrometry to determine plasma and CSF metabolite profiles. We semiquantitatively determined small-molecule levels (≤1.5 kDa in the plasma and CSF from early PD patients (disease duration 0–4 years; n = 80 and 40, respectively, and sex- and age-matched controls (n = 76 and 38, respectively. We performed statistical analyses utilizing partial least square and random forest analysis with a 70/30 training and testing split approach, leading to the identification of 20 promising plasma and 14 CSF metabolites. These metabolites differentiated the test set with an AUC of 0.8 (plasma and 0.9 (CSF. Characteristics of the metabolites indicate perturbations in the glycerophospholipid, sphingolipid, and amino acid metabolism in PD, which underscores the high power of metabolomic approaches. Further studies will enable to develop a potential metabolite-based biomarker panel specific for PD.

  12. Optimization of tungsten-steel joints for plasma facing components in fusion reactors

    Energy Technology Data Exchange (ETDEWEB)

    Heuer, Simon; Linsmeier, Christian [Forschungszentrum Juelich GmbH, Institut fuer Energie- und Klimaforschung - Plasmaphysik, Juelich (Germany); Weber, Thomas; Linke, Jochen [Forschungszentrum Juelich GmbH, Institut fuer Energie- und Klimaforschung - Werkstoffstruktur und -eigenschaften, Juelich (Germany); Matejicek, Jiri [Institute of Plasma Physics, Academy of Sciences of the Czech Republic, Prague (Czech Republic)

    2015-07-01

    Tungsten, joint to a martensitic-ferritic EUROFER97 structure, is a promising plasma facing material composite for fusion reactors. Due to the effect of mismatch in thermo-mechanical properties direct bonding is not feasible. Current research is therefore ongoing on interlayer systems. While the adhesion was already improved by the utilization of a discrete Cu, Ti or V interlayer, that is able to relax stresses by plastic deformation, joints still do not resist the expected load cycles in a fusion reactor. Therefore, alternatives for the interface are needed. This contribution presents research on functionally graded materials (FGM). The particular microstructure of a graded interlayer allows re-distributing macro stresses from a discrete interface to a greater volume while avoiding in particular Cu which tends to swell under neutron irradiation. A parameter study on the basis of finite element analysis will be presented as well as first results of several processing routes for FGM that shall be evaluated and benchmarked by mechanical as well as thermal testing.

  13. Controlled Fusion with Hot-ion Mode in a Degenerate Plasma

    International Nuclear Information System (INIS)

    S. Son and N.J. Fisch

    2005-01-01

    In a Fermi-degenerate plasma, the rate of electron physical processes is much reduced from the classical prediction, possibly enabling new regimes for controlled nuclear fusion, including the hot-ion mode, a regime in which the ion temperature exceeds the electron temperature. Previous calculations of these processes in dense plasmas are now corrected for partial degeneracy and relativistic effects, leading to an expanded regime of self-sustained fusion

  14. Coatings and claddings for the reduction of plasma contamination and surface erosion in fusion reactors

    International Nuclear Information System (INIS)

    Kaminsky, M.

    1980-01-01

    For the successful operation of plasma devices and future fusion reactors it is necessary to control plasma impurity release and surface erosion. Effective methods to obtain such controls include the application of protective coatings to, and the use of clad materials for, certain first wall components. Major features of the development programs for coatings and claddings for fusion applications will be described together with an outline of the testing program. A discussion of some pertinent test results will be included

  15. THz Backward-wave oscillators for plasma diagnostic in nuclear fusion

    OpenAIRE

    Paoloni, Claudio; Yue, Lingna; Tang, Xiaopin; Zhang, Fuzhi; Popovic, Branko; Himes, Logan; Barchfeld, Robert; Gamzina, Diana; Mineo, Mauro; Letizia, Rosa; Luhmann Jr., Neville C.

    2015-01-01

    Summary form only given. The understanding of plasma turbulence in nuclear fusion is related to the availability of powerful THz sources and the possibility to map wider plasma regions. A novel approach to realize compact THz sources to be implemented in the plasma diagnostic at NSTX experiment (Princeton Plasma Physics Laboratory, USA) is reported.Two novel 0.346 THz Backward-Wave Oscillators (BWOs) have been designed and are presently in the fabrication phase. One BWO is based on the Double...

  16. Plasma focus as an heavy ion source in the problem of heavy ion fusion

    International Nuclear Information System (INIS)

    Gribkov, V.A.; Dubrovskij, A.V.; Kalachev, N.V.; Krokhin, O.N.; Silin, P.V.; Nikulin, V.Ya.; Cheblukov, Yu.N.

    1984-01-01

    Results of experiments on the ion flux formation in a plasma focus (PF) to develop a multicharged ion source for thermonuclear facility driver are presented. In plasma focus accelerating section copper ions were injected. Advantages of the suggested method of ion beam formation are demonstrated. Beam emittance equalling < 0.1 cmxmrad is obtained. Plasma focus ion energy exceeds 1 MeV. Plasma focus in combination with a neodymium laser is thought to be a perspective ion source for heavy ion fusion

  17. Sausage instability of Z-discharged plasma channel in LIB-fusion device

    International Nuclear Information System (INIS)

    Murakami, H.; Kawata, S.; Niu, K.

    1982-07-01

    Current-carring plasma channels have been proposed for transporting intense ion beams from diodes to a target in a LIB-fusion device. In this paper, the growth rate of the most dangerous surface mode, that is, axisymmetric sausage instability is examined for the plasma channel. The growth rate is shown to be smaller than that of the plasma channel with no fluid motion in a sharp boundary. It is concluded that the stable plasma channel can be formed. (author)

  18. Atomic and plasma-material interaction data for fusion. V. 3

    International Nuclear Information System (INIS)

    1992-01-01

    This volume of Atomic and Plasma-Material Interaction Data for Fusion is devoted to atomic collision processes of helium atoms and of beryllium and boron atoms and ions in fusion plasmas. Most of the articles included in this volume are extended versions of the contributions presented at the IAEA experts' meetings on Atomic Data for Helium Beam Fusion Alpha Particle Diagnostics and on the Atomic Database for Beryllium and Boron, held in June 1991 at the IAEA headquarters in Vienna, or have resulted from the cross-section data analyses and evaluations performed by the working groups of these meetings. Refs, figs and tabs

  19. Atomic and Plasma-Material Interaction Data for Fusion. V. 16

    International Nuclear Information System (INIS)

    Braams, B.J.; Chung, H.-K.

    2014-03-01

    A wide variety of atomic, molecular, radiative and plasma-wall interaction processes involving a mixture of atoms, ions and molecules occur in the plasmas produced in nuclear fusion experiments. In the low temperature divertor and near wall region, molecules and molecular ions are formed. The plasma particles react with electrons and with each other. Plasma modelling requires cross-sections and rate coefficients for all these processes, and in addition spectral signatures to support interpretation of data from fusion experiments. The mission of the International Atomic Energy Agency Nuclear Data Section (IAEA/NDS) in the area of atomic and molecular data is to enhance the competencies of Member States in their research into nuclear fusion through the provision of internationally recommended atomic, molecular, plasma-material interaction and material properties databases. One mechanism by which the IAEA pursues this mission is the Coordinated Research Project (CRP). The present volume of Atomic and Plasma-Material Interaction Data for Fusion contains contributions from participants in the CRP 'Atomic and Molecular Data for Plasma Modelling' (2004-2008). This CRP was concerned with data for processes in the near wall and divertor plasma and plasma-wall interaction in fusion experiments, with focus on cross-sections for molecular reactions. Participants in the CRP came from 14 different institutes, many with strong ties to fusion plasma modelling and experiment. D. Humbert of the Nuclear Data Section was scientific secretary of the CRP. Participants' contributions for this volume were collected and refereed after the conclusion of the CRP

  20. Ion distribution in the hot spot of an inertial confinement fusion plasma

    Science.gov (United States)

    Tang, Xianzhu; Guo, Zehua; Berk, Herb

    2012-10-01

    Maximizing the fusion gain of inertial confinement fusion (ICF) for inertial fusion energy (IFE) applications leads to the standard scenario of central hot spot ignition followed by propagating burn wave through the cold/dense assembled fuel. The fact that the hot spot is surrounded by cold but dense fuel layer introduces subtle plasma physics which requires a kinetic description. Here we perform Fokker-Planck calculations and kinetic PIC simulations for an ICF plasma initially in pressure balance but having large temperature gradient over a narrow transition layer. The loss of the fast ion tail from the hot spot, which is important for fusion reactivity, is quantified by Fokker-Planck models. The role of electron energy transport and the ambipolar electric field is investigated via kinetic simulations and the fluid moment models. The net effect on both hot spot ion temperature and the ion tail distribution, and hence the fusion reactivity, is elucidated.

  1. The cross sections of fusion-evaporation reactions: the most promising route to superheavy elements beyond Z=118

    Directory of Open Access Journals (Sweden)

    Jadambaa Khuyagbaatar

    2017-01-01

    Full Text Available The synthesis of superheavy elements beyond oganesson (Og, which has atomic number Z = 118, is currently one of the main topics in nuclear physics. An absence of sufficient amounts of target material with atomic numbers heavier than californium (Z = 98 forces the use of projectiles heavier than 48Ca (Z = 20, which has been successfully used for the discoveries of elements with Z = 114 - 118 in complete fusion reactions. Experimental cross sections of 48Ca with actinide targets behave very differently to “cold” and “hot” fusion-evaporation reactions, where doubly-magic lead and deformed actinides are used as targets, respectively. The known cross sections of these reactions have been analysed compared to calculated fission barriers. It has been suggested that observed discrepancies between the cross sections of 48Ca-induced and other fusionevaporation reactions originate from the shell structure of the compound nucleus, which lies in the island of the stability. Besides scarcely known data on other reactions involving heavier projectiles, the most promising projectile for the synthesis of the elements beyond Og seems to be 50Ti. However, detailed studies of 50Ti, 54Cr, 58Fe and 64Ni-induced reactions are necessary to be performed in order to fully understand the complexities of superheavy element formation.

  2. The cross sections of fusion-evaporation reactions: the most promising route to superheavy elements beyond Z=118

    Science.gov (United States)

    Jadambaa, Khuyagbaatar

    2017-11-01

    The synthesis of superheavy elements beyond oganesson (Og), which has atomic number Z = 118, is currently one of the main topics in nuclear physics. An absence of sufficient amounts of target material with atomic numbers heavier than californium (Z = 98) forces the use of projectiles heavier than 48Ca (Z = 20), which has been successfully used for the discoveries of elements with Z = 114 - 118 in complete fusion reactions. Experimental cross sections of 48Ca with actinide targets behave very differently to "cold" and "hot" fusion-evaporation reactions, where doubly-magic lead and deformed actinides are used as targets, respectively. The known cross sections of these reactions have been analysed compared to calculated fission barriers. It has been suggested that observed discrepancies between the cross sections of 48Ca-induced and other fusionevaporation reactions originate from the shell structure of the compound nucleus, which lies in the island of the stability. Besides scarcely known data on other reactions involving heavier projectiles, the most promising projectile for the synthesis of the elements beyond Og seems to be 50Ti. However, detailed studies of 50Ti, 54Cr, 58Fe and 64Ni-induced reactions are necessary to be performed in order to fully understand the complexities of superheavy element formation.

  3. HIGH SPATIAL RESOLUTION IMAGING OF INERTIAL FUSION TARGET PLASMAS USING BUBBLE NEUTRON DETECTORS

    International Nuclear Information System (INIS)

    FISHER, R.K.

    2003-01-01

    OAK B202 HIGH SPATIAL RESOLUTION IMAGING OF INERTIAL FUSION TARGET PLASMAS USING BUBBLE NEUTRON DETECTORS. Bubble detectors, which can detect neutrons with a spatial 5 to 30 (micro), are the most promising approach to imaging NIF target plasmas with the desired 5 (micro) spatial resolution in the target plane. Gel bubble detectors are being tested to record neutron images of ICF implosions in OMEGA experiments. By improving the noise reduction techniques used in analyzing the data taken in June 2000, we have been able to image the neutron emission from 6 · 10 13 yield DT target plasmas with a target plane spatial resolution of ∼ 140 (micro). As expected, the spatial resolution was limited by counting statistics as a result of the low neutron detection efficiency of the easy-to-use gel bubble detectors. The results have been submitted for publication and will be the subject of an invited talk at the October 2001 Meeting of the Division of Plasma Physics of the American Physical Society. To improve the counting statistics, data was taken in May 2001 using a stack of four gel detectors and integrated over a series of up to seven high-yield DT shots. Analysis of the 2001 data is still in its early stages. Gel detectors were chosen for these initial tests since the bubbles can be photographed several hours after the neutron exposure. They consist of ∼ 5000 drops (∼ 100 (micro) in diameter) of bubble detector liquid/cm 3 suspended in an inactive support gel that occupies ∼ 99% of the detector volume. Using a liquid bubble chamber detector and a light scattering system to record the bubble locations a few microseconds after the neutron exposure when the bubbles are ∼ 10 (micro) in diameter, should result in ∼ 1000 times higher neutron detection efficiency and a target plane resolution on OMEGA of ∼ 10 to 50 (micro)

  4. Non linear dynamics of magnetic islands in fusion plasmas

    International Nuclear Information System (INIS)

    Meshcheriakov, D.

    2012-10-01

    In this thesis we investigate the issues of linear stability of the tearing modes in a presence of both curvature and diamagnetic rotation using the non linear full-MHD toroidal code XTOR-2F, which includes anisotropic heat transport, diamagnetic and geometrical effects. This analysis is applied to one of the fully non-inductive discharges on Tore-Supra. Such experiments are crucially important to demonstrate reactor scale steady state operation for the tokamak. The possibility of a full linear stabilization of the tearing modes by diamagnetic rotation in the presence of toroidal curvature is shown. The stabilization threshold does not follow the classical scaling law connecting the growth rate of islands to plasma conductivity, measured here by the Lundquist number (S). However, for numerical reasons, the conductivity used in the simulations is lower than that of the experiment, which raises the question of extrapolation of the obtained results to the experimental situation. The extrapolation of the obtained results requires simulations with several different conductivities. It predicts that the mode at q = 2 surface to be stable at value of diamagnetic frequency consistent with the experimental one at S = S(exp). In the linearly stable domain, the mode is metastable: saturation level depends on the seed island size. In the non linear regime, the saturation of n=1, m=2 mode is found to be strongly reduced by diamagnetic rotation and by Lundquist number. However, the extrapolation to the experimental situation shows that if the island is destabilized, it will saturate at a detectable level for the Tore Supra diagnostic. For a large plasma aspect ratio (i.e. weak curvature effects), the reduction of the saturated width by diamagnetic frequency takes the form of a jump reminiscent of multiple states evidenced in slab geometry case. The question of extrapolation of the obtained results towards future generation of fusion devices is also addressed. In particular, for

  5. System and method for generating steady state confining current for a toroidal plasma fusion reactor

    International Nuclear Information System (INIS)

    Fisch, N.J.

    1981-01-01

    A system for generating steady state confining current for a toroidal plasma fusion reactor providing steady-state generation of the thermonuclear power. A dense, hot toroidal plasma is initially prepared with a confining magnetic field with toroidal and poloidal components. Continuous wave rf energy is injected into said plasma to establish a spectrum of traveling waves in the plasma, where the traveling waves have momentum components substantially either all parallel, or all anti-parallel to the confining magnetic field. The injected rf energy is phased to couple to said traveling waves with both a phase velocity component and a wave momentum component in the direction of the plasma traveling wave components. The injected rf energy has a predetermined spectrum selected so that said traveling waves couple to plasma electrons having velocities in a predetermined range delta . The velocities in the range are substantially greater than the thermal electron velocity of the plasma. In addition, the range is sufficiently broad to produce a raised plateau having width delta in the plasma electron velocity distribution so that the plateau electrons provide steady-state current to generate a poloidal magnetic field component sufficient for confining the plasma. In steady state operation of the fusion reactor, the fusion power density in the plasma exceeds the power dissipated in the plasma

  6. System and method for generating steady state confining current for a toroidal plasma fusion reactor

    International Nuclear Information System (INIS)

    Bers, A.

    1981-01-01

    A system for generating steady state confining current for a toroidal plasma fusion reactor providing steady-state generation of the thermonuclear power. A dense, hot toroidal plasma is initially prepared with a confining magnetic field with toroidal and poloidal components. Continuous wave rf energy is injected into said plasma to estalish a spectrum of traveling waves in the plasma, where the traveling waves have momentum components substantially either all parallel, or all anti-parallel to the confining magnetic field. The injected rf energy is phased to couple to said traveling waves with both a phase velocity component and a wave momentum component in the direction of the plasma traveling wave components. The injected rf energy has a predetermined spectrum selected so that said traveling waves couple to plasma electrons having velocities in a predetermined range delta . The velocities in the range are substantially greater than the thermal electron velocity of the plasma. In addition, the range is sufficiently broad to produce a raised plateau having width delta in the plasma electron velocity distribution so that the plateau electrons provide steady-state current to generate a poloidal magnetic field component sufficient for confining the plasma. In steady state operation of the fusion reactor, the fusion power density in the plasma exceeds the power dissipated inthe plasma

  7. Summaries of FY 1986 research in the Applied Plasma Physics Fusion Theory Program

    International Nuclear Information System (INIS)

    1987-12-01

    The Theory Program is charged with supporting the development of theories and models of plasmas for the fusion research effort. This work ranges from first-principles analysis of elementary plasma processes to empirical simulation of specific experiments. The Theory Program supports research by industrial contractors, US government laboratories, and universities. The university support also helps to fulfill the DOE mission of training scientists for the fusion program. The Theory Program is funded through the Fusion Theory Branch, Division of Applied Plasma Physics in the Office of Fusion Energy. The work is divided among 31 institutions, of which 19 are universities, five are industrial contractors, and seven are US government laboratories; see Table 1 for a complete list. The FY 1986 Theory Program budget was divided among theory types: toroidal, mirror, alternate concept, generic, and atomic. Device modeling is included among the other funding categories, and is not budgeted separately

  8. High precision measurement of fuel density profiles in nuclear fusion plasmas

    NARCIS (Netherlands)

    Svensson, J.; von Hellermann, M.; Konig, R.

    2002-01-01

    This paper presents a method for deducing fuel density profiles of nuclear fusion plasmas in realtime during an experiment. A Multi Layer Perceptron (MLP) neural network is used to create a mapping between plasma radiation spectra and indirectly deduced hydrogen isotope densities. By combining

  9. Control oriented modeling and simulation of the sawtooth instability in nuclear fusion tokamak plasmas

    NARCIS (Netherlands)

    Witvoet, G.; Westerhof, E.; Steinbuch, M.; Doelman, N.J.; Baar, de M.R.

    2009-01-01

    Tokamak plasmas in nuclear fusion are subject to various instabilities. A clear example is the sawtooth instability, which has both positive and negative effects on the plasma. To optimize between these effects control of the sawtooth period is necessary. This paper presents a simple control

  10. Atomic data for beam-stimulated plasma spectroscopy in fusion plasmas

    International Nuclear Information System (INIS)

    Marchuk, O.; Biel, W.; Schlummer, T.; Ralchenko, Yu.; Schultz, D. R.

    2013-01-01

    Injection of high energy atoms into a confined plasma volume is an established diagnostic technique in fusion research. This method strongly depends on the quality of atomic data for charge-exchange recombination spectroscopy (CXRS), motional Stark effect (MSE) and beam-emission spectroscopy (BES). We present some examples of atomic data for CXRS and review the current status of collisional data for parabolic states of hydrogen atoms that are used for accurate MSE modeling. It is shown that the collisional data require knowledge of the excitation density matrix including the off-diagonal matrix elements. The new datasets for transitions between parabolic states are used in an extended collisional-radiative model. The ratios between the σ- and π-components and the beam-emission rate coefficients are calculated in a quasi-steady state approximation. Good agreement with the experimental data from JET is found which points out to strong deviations from the statistical distribution for magnetic sublevels

  11. Plasma lens focusing and plasma channel transport for heavy ion fusion

    International Nuclear Information System (INIS)

    Tauschwitz, A.; Yu, S.S.; Bangerter, R.O.

    1996-01-01

    The final focus lens in an ion beam driven inertial confinement fusion reactor is important since it sets limiting requirements for the quality of the driver beam. Improvements of the focusing capabilities can facilitate the construction of the driver significantly. A focusing system that is of interest both for heavy ion and for light ion drivers is an adiabatic, current carrying plasma lens. This lens is characterized by the fact that it can slowly (adiabatically) reduce the envelope radius of a beam over several betatron oscillations by increasing the focusing magnetic field along a tapered high current discharge. A reduction of the beam diameter by a factor of 3 to 5 seems feasible with this focusing scheme. Such a lens can be used for an ignition test facility where it can be directly coupled to the fusion target. For use in a repetitively working reactor chamber the lens has to be located outside of the reactor and the tightly focused but strongly divergent beam must be confined in a high current transport channel from the end of the lens into the immediate vicinity of the target. Laser preionization of a background gas is an efficient means to direct and stabilize such a channel. Experiments have been started to test both, the principle of adiabatic focusing, and the stability of laser preionized high current discharge channels. (author). 4 figs., 7 refs

  12. Plasma lens focusing and plasma channel transport for heavy ion fusion

    Energy Technology Data Exchange (ETDEWEB)

    Tauschwitz, A; Yu, S S; Bangerter, R O [Lawrence Berkeley Lab., CA (United States); and others

    1997-12-31

    The final focus lens in an ion beam driven inertial confinement fusion reactor is important since it sets limiting requirements for the quality of the driver beam. Improvements of the focusing capabilities can facilitate the construction of the driver significantly. A focusing system that is of interest both for heavy ion and for light ion drivers is an adiabatic, current carrying plasma lens. This lens is characterized by the fact that it can slowly (adiabatically) reduce the envelope radius of a beam over several betatron oscillations by increasing the focusing magnetic field along a tapered high current discharge. A reduction of the beam diameter by a factor of 3 to 5 seems feasible with this focusing scheme. Such a lens can be used for an ignition test facility where it can be directly coupled to the fusion target. For use in a repetitively working reactor chamber the lens has to be located outside of the reactor and the tightly focused but strongly divergent beam must be confined in a high current transport channel from the end of the lens into the immediate vicinity of the target. Laser preionization of a background gas is an efficient means to direct and stabilize such a channel. Experiments have been started to test both, the principle of adiabatic focusing, and the stability of laser preionized high current discharge channels. (author). 4 figs., 7 refs.

  13. PFMC-16. 16th international conference on plasma-facing materials and components for fusion applications. Abstracts

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2017-07-01

    The performances of fusion devices and of future fusion power plants strongly depend on the plasma-facing materials and components. Resistance to heat and particle loads, compatibility in plasma operations, thermo-mechanical properties, as well as the response to neutron irradiation are critical parameters which need to be understood and tailored from atomistic to component levels. The 16th International Conference on Plasma-Facing Materials and Components for Fusion Applications addresses these issues.

  14. Observation of neoclassical transport in reverse shear plasmas on the tokamak fusion test reactor

    International Nuclear Information System (INIS)

    Efthimion, P.C.; Goeler, S. von; Houlberg, W.A.

    2001-01-01

    Perturbative experiments on the Tokamak Fusion Test Reactor (TFTR) have investigated the transport of multiple ion species in reverse shear plasmas. The profile evolution of trace tritium and helium, and intrinsic carbon indicate the formation of core particle transport barriers in ERS plasmas. There is an order of magnitude reduction in the particle diffusivity inside the reverse shear region. The diffusivities for these species in ERS plasmas agree with neoclassical theory. (author)

  15. Observation of neoclassical transport in reverse shear plasmas on the tokamak fusion test reactor

    International Nuclear Information System (INIS)

    Efthimion, P.C.; Von Goeler, S.; Houlberg, W.A.

    1999-01-01

    Perturbative experiments on the Tokamak Fusion Test Reactor (TFTR) have investigated the transport of multiple ion species in reverse shear plasmas. The profile evolution of trace tritium and helium, and intrinsic carbon indicate the formation of core particle transport barriers in ERS plasmas. There is an order of magnitude reduction in the particle diffusivity inside the reverse shear region. The diffusivities for these species in ERS plasmas agree with neoclassical theory. (author)

  16. Comparison of fusion alpha performance in JET advanced scenario and H-mode plasmas

    Energy Technology Data Exchange (ETDEWEB)

    Asunta, O; Kurki-Suonio, T; Tala, T; Sipilae, S; Salomaa, R [JET-EFDA, Culham Science Centre, OX14 3DB, Abingdon (United Kingdom)], E-mail: Otto.Asunta@tkk.fi

    2008-12-15

    Currently, plasmas with internal transport barriers (ITBs) appear the most likely candidates for steady-state scenarios for future fusion reactors. In such plasmas, the broad hot and dense region in the plasma core leads to high fusion gain, while the cool edge protects the integrity of the first wall. Economically desirable large bootstrap current fraction and low inductive current drive may, however, lead to degraded fast ion confinement. In this work the confinement and heating profile of fusion alphas were compared between H-mode and ITB plasmas in realistic JET geometry. The work was carried out using the Monte Carlo-based guiding-center-following code ASCOT. For the same plasma current, the ITB discharges were found to produce four to eight times more fusion power than a comparable ELMy H-mode discharge. Unfortunately, also the alpha particle losses were larger ({approx}16%) compared with the H-mode discharge (7%). In the H-mode discharges, alpha power was deposited to the plasma symmetrically around the magnetic axis, whereas in the current-hole discharge, the power was spread out to a larger volume in the plasma center. This was due to wider particle orbits, and the magnetic structure allowing for a broader hot region in the centre.

  17. NATO Advanced Study Institute entitled Physics of Plasma-Wall Interactions in Controlled Fusion

    CERN Document Server

    Behrisch, R; Physics of plasma-wall interactions in controlled fusion

    1986-01-01

    Controlled thermonuclear fusion is one of the possible candidates for long term energy sources which will be indispensable for our highly technological society. However, the physics and technology of controlled fusion are extremely complex and still require a great deal of research and development before fusion can be a practical energy source. For producing energy via controlled fusion a deuterium-tritium gas has to be heated to temperatures of a few 100 Million °c corres­ ponding to about 10 keV. For net energy gain, this hot plasma has to be confined at a certain density for a certain time One pro­ mising scheme to confine such a plasma is the use of i~tense mag­ netic fields. However, the plasma diffuses out of the confining magnetic surfaces and impinges on the surrounding vessel walls which isolate the plasma from the surrounding air. Because of this plasma wall interaction, particles from the plasma are lost to the walls by implantation and are partially reemitted into the plasma. In addition, wall...

  18. Vacuum Plasma Spraying W-coated Reduced Activation Structural Steels for Fusion Plasma Facing Components

    Energy Technology Data Exchange (ETDEWEB)

    Noh, Sanghoon; Kim, Tae Kyu [Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of)

    2014-05-15

    Tungsten (W) and its alloys are considered as candidate materials for plasma facing materials of the first wall and diverter components in fusion reactor systems because of high sputtering resistance and low tritium retention in a fusion environment. Therefore, it is considered that the joining between W and reduced activation structural steels, and its evaluation, are critical issues for the development of fusion reactors. However, the joining between these materials is a very challenging process because of significant differences in their physical properties, particularly the mismatch of coefficients of thermal expansion (CTE). For instance, the CTE of pure W is known to be about 4.3Χ10{sup -6}K{sup -1}; however, that of martensitic steels reaches over three times, about 12-14Χ10{sup -6}K{sup -1} at room temperature even up to 373K. Nevertheless, several joining techniques have been developed for joining between W and structural steels, such as a vapor deposition method, brazing and diffusion bonding. Meanwhile, vacuum plasma spraying (VPS) is supposed to be one of the prospective methods to fabricate a sufficient W layer on the steel substrates because of the coating of a large area with a relatively high fabricating rate. In this study, the VPS method of W powders on reduced activation steels was employed, and its microstructure and hardness distribution were investigated. ODS ferritic steels and F82H steel were coated by VPS-W, and the microstructure and hardness distribution were investigated. A microstructure analysis revealed that pure W was successfully coated on steel substrates by the VPS process without an intermediate layer, in spite of a mismatch of the CTE between dissimilar materials. After neutron irradiation, irradiation hardening significantly occurred in the VPSW. However, the hardening of VPS-W was lesser than that of bulk W irradiated HFIR at 773K. Substrate materials, ODS ferritic steels, and F82H steel, did not show irradiation hardening

  19. Properties of plasma sheath with ion temperature in magnetic fusion devices

    International Nuclear Information System (INIS)

    Liu Jinyuan; Wang Feng; Sun Jizhong

    2011-01-01

    The plasma sheath properties in a strong magnetic field are investigated in this work using a steady state two-fluid model. The motion of ions is affected heavily by the strong magnetic field in fusion devices; meanwhile, the effect of ion temperature cannot be neglected for the plasma in such devices. A criterion for the plasma sheath in a strong magnetic field, which differs from the well-known Bohm criterion for low temperature plasma sheath, is established theoretically with a fluid model. The fluid model is then solved numerically to obtain detailed sheath information under different ion temperatures, plasma densities, and magnetic field strengths.

  20. Massachusetts Institute of Technology Plasma Fusion Center 1987--1988 report to the President

    International Nuclear Information System (INIS)

    1988-06-01

    During the past year, technical progress has been made in all Plasma Fusion Center (PFC) research programs. The Plasma Fusion Center is recognized as one of the leading university research laboratories in the physics and engineering aspects of magnetic confinement fusion. Its research programs have produced significant results on several fronts: the basic physics of high-temperature plasmas (plasmas theory, RF heating, free electron lasers, development of advanced diagnostics, and intermediate-scale experiments on the Versator tokamak and Constance mirror devices), major confinement results on the Alcator C tokamak, including pioneering investigations of the stability, heating, and confinement properties of plasmas at high densities, temperatures and magnetic fields, experiments on the medium-scale TARA tandem mirror, including the development of novel MHD stabilization techniques in axisymmetric geometry, and a broad program of fusion technology and engineering development that addresses problems in several critical subsystem areas (e.g., magnet systems, superconducting materials development, environmental and safety studies, advanced millimeter-wave source development, and system studies of fusion reactor design, operation, and technology requirements

  1. Massachusetts Institute of Technology, Plasma Fusion Center, 1984-1985. Report to the President

    International Nuclear Information System (INIS)

    1985-07-01

    During the past year, technical progress has been made in all Plasma Fusion Center (PFC) research programs. The Plasma Fusion Center is recognized as one of the leading university research laboratories in the physics and engineering aspects of magnetic confinement fusion. Its research programs have produced significant results on four fronts: (1) the basic physics of high-temperature plasmas (plasma theory, rf heating, free electron lasers, development of advanced diagnostics and small-scale experiments on the Versator tokamak and Constance mirror devices); (2) major confinement results on the Alcator C tokamak, including pioneering investigations of the stability, heating, and confinement properties of plasmas at high densities, temperatures and magnetic fields; (3) development of an innovative design for axisymmetric tandem mirrors with inboard thermal barriers, with initial operation of the TARA tandem mirror experiment beginning in 1984; and (4) a broad program of fusion technology and engineering development that addresses problems in several critical subsystem areas (e.g., magnet systems, superconducting materials development, environmental and safety studies, advanced millimeter wave source development, and system studies of fusion reactor design, operation, and technology requirements). A review of these programs is given

  2. Binding and Fusion of Extracellular Vesicles to the Plasma Membrane of Their Cell Targets.

    Science.gov (United States)

    Prada, Ilaria; Meldolesi, Jacopo

    2016-08-09

    Exosomes and ectosomes, extracellular vesicles of two types generated by all cells at multivesicular bodies and the plasma membrane, respectively, play critical roles in physiology and pathology. A key mechanism of their function, analogous for both types of vesicles, is the fusion of their membrane to the plasma membrane of specific target cells, followed by discharge to the cytoplasm of their luminal cargo containing proteins, RNAs, and DNA. Here we summarize the present knowledge about the interactions, binding and fusions of vesicles with the cell plasma membrane. The sequence initiates with dynamic interactions, during which vesicles roll over the plasma membrane, followed by the binding of specific membrane proteins to their cell receptors. Membrane binding is then converted rapidly into fusion by mechanisms analogous to those of retroviruses. Specifically, proteins of the extracellular vesicle membranes are structurally rearranged, and their hydrophobic sequences insert into the target cell plasma membrane which undergoes lipid reorganization, protein restructuring and membrane dimpling. Single fusions are not the only process of vesicle/cell interactions. Upon intracellular reassembly of their luminal cargoes, vesicles can be regenerated, released and fused horizontally to other target cells. Fusions of extracellular vesicles are relevant also for specific therapy processes, now intensely investigated.

  3. Fusion plasma diagnostics with mm-waves an introduction

    CERN Document Server

    Hartfuss, Hans-Jürgen

    2013-01-01

    Filling a gap in the literature, this introduction to the topic covers the physics of the standard microwave diagnostics established on modern fusion experiments, and the necessary technological background from the field of microwave engineering. Written by well-known mm-wave diagnosticians in the field of fusion physics, the textbook includes such major diagnostic techniques as electron cyclotron emission, interferometry, reflectometry, polarimetry, and scattering.

  4. Fusion reactions initiated by laser-accelerated particle beams in a laser-produced plasma

    International Nuclear Information System (INIS)

    Labaune, C.; Baccou, C.; Loisel, G.; Yahia, V.; Depierreux, S.; Goyon, C.; Rafelski, J.

    2013-01-01

    The advent of high-intensity-pulsed laser technology enables the generation of extreme states of matter under conditions that are far from thermal equilibrium. This in turn could enable different approaches to generating energy from nuclear fusion. Relaxing the equilibrium requirement could widen the range of isotopes used in fusion fuels permitting cleaner and less hazardous reactions that do not produce high-energy neutrons. Here we propose and implement a means to drive fusion reactions between protons and boron-11 nuclei by colliding a laser-accelerated proton beam with a laser-generated boron plasma. We report proton-boron reaction rates that are orders of magnitude higher than those reported previously. Beyond fusion, our approach demonstrates a new means for exploring low-energy nuclear reactions such as those that occur in astrophysical plasmas and related environments. (authors)

  5. Comparative study of the more promising combinations of blanket materials, power conversion systems, and tritium recovery and containment systems for fusion reactors

    International Nuclear Information System (INIS)

    Fraas, A.P.

    1975-11-01

    The many possible combinations of blanket materials, tritium generation and recovery systems, and power conversion systems were surveyed first by reviewing the principal design studies that have been prepared and then by examining a comprehensive set of designs generated by using a common set of ground rules that included all of the boundary conditions that could be envisioned. The results indicate that, of the wide variety of systems that have been considered, by far the most promising employs lithium recirculated in a closed loop within a niobium blanket structure and cooled with boiling potassium or cesium. This approach gives the simplest and lowest cost tritium recovery system, the lowest pressure and thermal stresses, the simplest structure with the lowest probability of a leak, the greatest resistance to damage from a plasma energy dump, and the lowest rate of plasma contamination by either outgassing or sputtering. The only other blanket materials combination that appears fairly likely to give a satisfactory tritium generation and recovery system is an Li 2 BeF 4 -Incoloy blanket, and even this system involves major uncertainties in the effectiveness, size, and cost of the tritium recovery system. Further, the Li 2 BeF 4 blanket system has the disadvantage that the world reserves of beryllium are too limited to support a full-blown fusion reactor economy, its poor thermal conductivity leads to cooling difficulties and a requirement for a complex structure with intricate cooling passages, and this inherently leads to an expensive blanket with a relatively high probability of leaks. The other blanket materials combinations yield even less attractive systems

  6. Simulations of plasma heating caused by the coalescence of multiple current loops in a proton-boron fusion plasma

    International Nuclear Information System (INIS)

    Haruki, T.; Yousefi, H. R.; Sakai, J.-I.

    2010-01-01

    Two dimensional particle-in-cell simulations of a dense plasma focus were performed to investigate a plasma heating process caused by the coalescence of multiple current loops in a proton-boron-electron plasma. Recently, it was reported that the electric field produced during the coalescence of two current loops in a proton-boron-electron plasma heats up all plasma species; proton-boron nuclear fusion may therefore be achievable using a dense plasma focus device. Based on this work, the coalescence process for four and eight current loops was investigated. It was found that the return current plays an important role in both the current pinch and the plasma heating. The coalescence of four current loops led to the breakup of the return current from the pinched plasma, resulting in plasma heating. For the coalescence of eight current loops, the plasma was confined by the pinch but the plasma heating was smaller than the two and four loop cases. Therefore the heating associated with current loop coalescence depends on the number of initial current loops. These results are useful for understanding the coalescence of multiple current loops in a proton-boron-electron plasma.

  7. Membrane fusion by VAMP3 and plasma membrane t-SNAREs

    International Nuclear Information System (INIS)

    Hu Chuan; Hardee, Deborah; Minnear, Fred

    2007-01-01

    Pairing of SNARE (soluble N-ethylmaleimide-sensitive factor attachment protein receptor) proteins on vesicles (v-SNAREs) and SNARE proteins on target membranes (t-SNAREs) mediates intracellular membrane fusion. VAMP3/cellubrevin is a v-SNARE that resides in recycling endosomes and endosome-derived transport vesicles. VAMP3 has been implicated in recycling of transferrin receptors, secretion of α-granules in platelets, and membrane trafficking during cell migration. Using a cell fusion assay, we examined membrane fusion capacity of the ternary complexes formed by VAMP3 and plasma membrane t-SNAREs syntaxin1, syntaxin4, SNAP-23 and SNAP-25. VAMP3 forms fusogenic pairing with t-SNARE complexes syntaxin1/SNAP-25, syntaxin1/SNAP-23 and syntaxin4/SNAP-25, but not with syntaxin4/SNAP-23. Deletion of the N-terminal domain of syntaxin4 enhanced membrane fusion more than two fold, indicating that the N-terminal domain negatively regulates membrane fusion. Differential membrane fusion capacities of the ternary v-/t-SNARE complexes suggest that transport vesicles containing VAMP3 have distinct membrane fusion kinetics with domains of the plasma membrane that present different t-SNARE proteins

  8. Fusion power production from TFTR plasmas fueled with deuterium and tritium

    International Nuclear Information System (INIS)

    Strachan, J.D.; Adler, H.; Alling, P.

    1994-03-01

    Peak fusion power production of 6.2 ± 0.4 MW has been achieved in TFTR plasmas heated by deuterium and tritium neutral beams at a total power of 29.5 MW. These plasmas have an inferred central fusion alpha particle density of 1.2 x 10 17 m -3 without the appearance of either disruptive MHD events or detectable changes in Alfven wave activity. The measured loss rate of energetic alpha particles agreed with the approximately 5% losses expected from alpha particles which are born on unconfined orbits

  9. A conceptual fusion reactor based on the high-plasma-density Z-pinch

    International Nuclear Information System (INIS)

    Hartman, C.W.; Carlson, G.; Hoffman, M.; Werner, R.

    1977-01-01

    Conceptual DT and DD fusion reactors are discussed based on magnetic confinement with the high-plasma-density Z-pinch. The reactor concepts have no ''first wall'', the fusion neutrons and plasma energy being absorbed directly into a surrounding lithium vortex blanket. Efficient systems with low re-circulated power are projected, based on a flow-through pinch cycle for which overall Q values can approach 10. The conceptual reactors are characterized by simplicity, small minimum size (100MW(e)) and by the potential for minimal radioactivity hazards. (author)

  10. 13th EU-US Transport Task Force Workshop on transport in fusion plasmas

    DEFF Research Database (Denmark)

    Connor, J.W.; Fasoli, A.; Hidalgo, C.

    2009-01-01

    This report summarizes the contributions presented at the 13th EU-US Transport Task Force Workshop on transport in fusion plasmas, held in Copenhagen, Denmark, 1-4 September 2008. There were sessions on core heat and particle transport; core and edge momentum transport; edge and scrape-off-layer ......This report summarizes the contributions presented at the 13th EU-US Transport Task Force Workshop on transport in fusion plasmas, held in Copenhagen, Denmark, 1-4 September 2008. There were sessions on core heat and particle transport; core and edge momentum transport; edge and scrape...

  11. Fusion energy

    International Nuclear Information System (INIS)

    Gross, R.A.

    1984-01-01

    This textbook covers the physics and technology upon which future fusion power reactors will be based. It reviews the history of fusion, reaction physics, plasma physics, heating, and confinement. Descriptions of commercial plants and design concepts are included. Topics covered include: fusion reactions and fuel resources; reaction rates; ignition, and confinement; basic plasma directory; Tokamak confinement physics; fusion technology; STARFIRE: A commercial Tokamak fusion power plant. MARS: A tandem-mirror fusion power plant; and other fusion reactor concepts

  12. Influence of fast waves on the collective scattering of microwaves in fusion plasmas

    International Nuclear Information System (INIS)

    Chiu, S.C.

    1992-01-01

    Microwave scattering by the fluctuations of fusion plasmas is one of the most promising α-diagnostic techniques. Previous investigations have concentrated on the fluctuations near the slow wave branch in the lower hybrid range of frequencies. The small signal and the lack of sensitivity to the contribution of α-particles to the total cross-section near the slow branch severely limits the effectiveness of this technique. In this paper, we report results of investigations of scattering by fluctuations in the lower hybrid range of frequencies near the fast branch. Surprisingly, when both fast and slow branches exist, the scattering amplitudes are comparable. More important, the α-contribution is larger for the fast branch and the fast branch has a larger parameter space where it exists. Specifically, the slow branch exists only above the lower hybrid frequency, while the fast branch can exist at all frequencies up to the electron cyclotron range of frequencies. We find numerically that the scattering amplitudes near the fast branch below the lower hybrid frequency are several orders of magnitude larger than those near the slow branch above that frequency where it can exist. This may make microwave scattering by fast waves a more attractive α-diagnostic technique. (orig.)

  13. FUSION ENERGY SCIENCES WORKSHOP ON PLASMA MATERIALS INTERACTIONS: Report on Science Challenges and Research Opportunities in Plasma Materials Interactions

    Energy Technology Data Exchange (ETDEWEB)

    Maingi, Rajesh [Princeton Plasma Physics Lab. (PPPL), Princeton, NJ (United States); Zinkle, Steven J. [University of Tennessee – Knoxville; Foster, Mark S. [U.S. Department of Energy

    2015-05-01

    The realization of controlled thermonuclear fusion as an energy source would transform society, providing a nearly limitless energy source with renewable fuel. Under the auspices of the U.S. Department of Energy, the Fusion Energy Sciences (FES) program management recently launched a series of technical workshops to “seek community engagement and input for future program planning activities” in the targeted areas of (1) Integrated Simulation for Magnetic Fusion Energy Sciences, (2) Control of Transients, (3) Plasma Science Frontiers, and (4) Plasma-Materials Interactions aka Plasma-Materials Interface (PMI). Over the past decade, a number of strategic planning activities1-6 have highlighted PMI and plasma facing components as a major knowledge gap, which should be a priority for fusion research towards ITER and future demonstration fusion energy systems. There is a strong international consensus that new PMI solutions are required in order for fusion to advance beyond ITER. The goal of the 2015 PMI community workshop was to review recent innovations and improvements in understanding the challenging PMI issues, identify high-priority scientific challenges in PMI, and to discuss potential options to address those challenges. The community response to the PMI research assessment was enthusiastic, with over 80 participants involved in the open workshop held at Princeton Plasma Physics Laboratory on May 4-7, 2015. The workshop provided a useful forum for the scientific community to review progress in scientific understanding achieved during the past decade, and to openly discuss high-priority unresolved research questions. One of the key outcomes of the workshop was a focused set of community-initiated Priority Research Directions (PRDs) for PMI. Five PRDs were identified, labeled A-E, which represent community consensus on the most urgent near-term PMI scientific issues. For each PRD, an assessment was made of the scientific challenges, as well as a set of actions

  14. Magnetic Probe to Study Plasma Jets for Magneto-Inertial Fusion

    Energy Technology Data Exchange (ETDEWEB)

    Martens, Daniel [Los Alamos National Laboratory; Hsu, Scott C. [Los Alamos National Laboratory

    2012-08-16

    A probe has been constructed to measure the magnetic field of a plasma jet generated by a pulsed plasma rail-gun. The probe consists of two sets of three orthogonally-oriented commercial chip inductors to measure the three-dimensional magnetic field vector at two separate positions in order to give information about the magnetic field evolution within the jet. The strength and evolution of the magnetic field is one of many factors important in evaluating the use of supersonic plasma jets for forming imploding spherical plasma liners as a standoff driver for magneto-inertial fusion.

  15. NSPEC - A neutron spectrum code for beam-heated fusion plasmas

    International Nuclear Information System (INIS)

    Scheffel, J.

    1983-06-01

    A 3-dimensional computer code is described, which computes neutron spectra due to beam heating of fusion plasmas. Three types of interactions are considered; thermonuclear of plasma-plasma, beam-plasma and beam-beam interactions. Beam deposition is modelled by the NFREYA code. The applied steady state beam distribution as a function of pitch angle and velocity contains the effects of energy diffusion, friction, angular scattering, charge exchange, electric field and source pitch angle distribution. The neutron spectra, generated by Monte-Carlo methods, are computed with respect to given lines of sight. This enables the code to be used for neutron diagnostics. (author)

  16. Plasma-material interactions in current tokamaks and their implications for next step fusion reactors

    International Nuclear Information System (INIS)

    Federici, G.; Skinner, C.H.; Brooks, J.N.

    2001-01-01

    The major increase in discharge duration and plasma energy in a next step DT fusion reactor will give rise to important plasma-material effects that will critically in influence its operation, safety and performance. Erosion will increase to a scale of several centimetres from being barely measurable at a micron scale in today's tokamaks. Tritium co-deposited with carbon will strongly affect the operation of machines with carbon plasma facing components. Controlling plasma-wall interactions is critical to achieving high performance in present day tokamaks, and this is likely to continue to be the case in the approach to practical fusion reactors. Recognition of the important consequences of these phenomena stimulated an internationally co-ordinated effort in the part of plasma-surface interactions supporting the Engineering Design Activities of the International Thermonuclear Experimental Reactor project (ITER), and significant progress has been made in better understanding these issues. The paper reviews the underlying physical processes and the existing experimental database of plasma-material inter actions both in tokamaks and laboratory simulation facilities for conditions of direct relevance to next step fusion reactors. Two main topical groups of interaction are considered: (i) erosion/redeposition from plasma sputtering and disruptions, including dust and flake generation and (ii) tritium retention and removal. The use of modelling tools to interpret the experimental results and make projections for conditions expected in future devices is explained. Outstanding technical issues and specific recommendations on potential R and D avenues for their resolution are presented. (author)

  17. Plasma-material interactions in current tokamaks and their implications for next-step fusion reactors

    International Nuclear Information System (INIS)

    Federici, G.; Skinner, C.H.; Brooks, J.N.

    2001-01-01

    The major increase in discharge duration and plasma energy in a next-step DT fusion reactor will give rise to important plasma-material effects that will critically influence its operation, safety and performance. Erosion will increase to a scale of several cm from being barely measurable at a micron scale in today's tokamaks. Tritium co-deposited with carbon will strongly affect the operation of machines with carbon plasma-facing components. Controlling plasma wall interactions is critical to achieving high performance in present-day tokamaks and this is likely to continue to be the case in the approach to practical fusion reactors. Recognition of the important consequences of these phenomena has stimulated an internationally co-ordinated effort in the field of plasma-surface interactions supporting the engineering design activities of the international thermonuclear experimental reactor project (ITER) and significant progress has been made in better understanding these issues. This paper reviews the underlying physical processes and the existing experimental database of plasma-material interactions both in tokamaks and laboratory simulation facilities for conditions of direct relevance to next-step fusion reactors. Two main topical groups of interactions are considered: (i) erosion/re-deposition from plasma sputtering and disruptions, including dust and flake generation, (ii) tritium retention and removal. The use of modelling tools to interpret the experimental results and make projections for conditions expected in future devices is explained. Outstanding technical issues and specific recommendations on potential R and D avenues for their resolution are presented. (orig.)

  18. Ignition of an overheated, underdense, fusioning tokamak plasma

    International Nuclear Information System (INIS)

    Singer, C.E.; Jassby, D.L.; Hovey, J.

    1979-08-01

    Methods of igniting an overheated but underdense D-T plasma core with a cold plasma blanket are investigated using a simple two-zone model with a variety of transport scaling laws, and also using a one-dimensional transport code. The power consumption of neutral-beam injectors required to produce ignition can be reduced significantly if the underdense core plasma is heated to temperatures much higher than the final equilibrium ignition values, followed by fueling from a cold plasma blanket. It is also found that the allowed impurity concentration in the initial hot core can be greater than normally permitted for ignition provided that the blanket is free from impurities

  19. Analysis of plasma behavior in a magnetic nozzle of laser fusion rocket

    International Nuclear Information System (INIS)

    Nagamine, Yoshihiko; Yoshimi, Naofumi; Nakama, Yuji; Muranaka, Takanobu; Mayumi, Takao; Nakashima, Hideki

    1997-01-01

    A magnetic nozzle concept in a laser fusion rocket is suitable for controlling the fusion plasma flow and it has an advantage that thermalization with wall structures in a thrust chamber can be avoided. Rayleigh-Taylor instability would occur at the surface of expanding plasma and it would lead to the degradation of thrust efficiency, due to diffusion of the plasma through ambient decelerating magnetic field. A 3D hybrid particle-in-cell code has been developed to analyze the plasma instability in the magnetic nozzle. The resultant linear growth rate γ of the instability is found to be 2.96 x 10 6 and it is in good agreement with the theoretical value from conventional Rayleigh Taylor instability. (author)

  20. Dynamical interplay between fluctuations, electric fields and transport in fusion plasmas

    International Nuclear Information System (INIS)

    Hidalgo, C.; Pedrosa, M.A.; Goncalves, B.

    2003-01-01

    A view of recent experimental results and progress in the characterization of the statistical properties of electrostatic turbulence in magnetically confined devices is given. An empirical similarity in the scaling properties of the probability distribution function (PDF) of turbulent transport has been observed in the plasma edge region in fusion plasmas. The investigation of the dynamical interplay between fluctuation in gradients, turbulent transport and radial electric fields has shows that these parameters are strongly coupled both in tokamak and stellarator plasmas. The bursty behaviour of turbulent transport is linked with a departure from the most probable radial gradient. The dynamical relation between fluctuations in gradients and transport is strongly affected by the presence of sheared poloidal flows which organized themselves near marginal stability. These results emphasize the importance of the statistical description of transport processes in fusion plasmas as an alternative approach to the traditional way to characterize transport based on the computation of effective transport coefficients. (author)

  1. Principles of fuel ion ratio measurements in fusion plasmas by collective Thomson scattering

    DEFF Research Database (Denmark)

    Stejner Pedersen, Morten; Nielsen, Stefan Kragh; Bindslev, Henrik

    2011-01-01

    ratio. Measurements of the fuel ion ratio will be important for plasma control and machine protection in future experiments with burning fusion plasmas. Here we examine the theoretical basis for fuel ion ratio measurements by CTS. We show that the sensitivity to plasma composition is enhanced......For certain scattering geometries collective Thomson scattering (CTS) measurements are sensitive to the composition of magnetically confined fusion plasmas. CTS therefore holds the potential to become a new diagnostic for measurements of the fuel ion ratio—i.e. the tritium to deuterium density...... by the signatures of ion cyclotron motion and ion Bernstein waves which appear for scattering geometries with resolved wave vectors near perpendicular to the magnetic field. We investigate the origin and properties of these features in CTS spectra and give estimates of their relative importance for fuel ion ratio...

  2. Quantum shielding effects on the Gamow penetration factor for nuclear fusion reaction in quantum plasmas

    Science.gov (United States)

    Lee, Myoung-Jae; Jung, Young-Dae

    2017-01-01

    The quantum shielding effects on the nuclear fusion reaction process are investigated in quantum plasmas. The closed expression of the classical turning point for the Gamow penetration factor in quantum plasmas is obtained by the Lambert W-function. The closed expressions of the Gamow penetration factor and the cross section for the nuclear fusion reaction in quantum plasmas are obtained as functions of the plasmon energy and the relative kinetic energy by using the effective interaction potential with the WKB analysis. It is shown that the influence of quantum screening suppresses the Sommerfeld reaction factor. It is also shown that the Gamow penetration factor increases with an increase of the plasmon energy. It is also shown that the quantum shielding effect enhances the deuterium formation by the proton-proton reaction in quantum plasmas. In addition, it is found that the energy dependences on the reaction cross section and the Gamow penetration factor are more significant in high plasmon-energy domains.

  3. 2001 activity report of the development and research line in controlled thermonuclear fusion of the Plasma Associated Laboratory

    International Nuclear Information System (INIS)

    Ludwig, Gerson Otto

    2002-01-01

    The year 2001 activities of the controlled thermonuclear fusion research line of the Plasma Associated Laboratory at the National Institute for Space Research - Brazil are reported. The report approaches the staff, participation in congresses, goals for the year 2002 and papers on Tokamak plasmas, plasma diagnostic, bootstraps, plasma equilibrium and diagnostic

  4. Structural stability analysis considerations in fusion reactor plasma chamber design

    International Nuclear Information System (INIS)

    Delaney, M.J.; Cramer, B.A.

    1978-01-01

    This paper presents an approach to analyzing a toroidal plasma chamber for the prevention of both static and dynamic buckling. Results of stability analyses performed for the doublet shaped plasma chamber of the General Atomic 3.8 meter radius TNS ignition test reactor are presented. Load conditions are the static external atmospheric pressure load and the dynamic plasma disruption pulse load. Methods for analysis of plasma chamber structures are presented for both types of load. Analysis for static buckling is based on idealizing the plasma chamber into standard structural shapes and applying classical cylinder and circular torus buckling equations. Results are verified using the Buckling of Shells of Revolution (BOSOR4) finite difference computer code. Analysis for the dynamic loading is based on a pulse buckling analysis method for circular cylinders

  5. Development of time dependent safety analysis code for plasma anomaly events in fusion reactors

    International Nuclear Information System (INIS)

    Honda, Takuro; Okazaki, Takashi; Bartels, H.W.; Uckan, N.A.; Seki, Yasushi.

    1997-01-01

    A safety analysis code SAFALY has been developed to analyze plasma anomaly events in fusion reactors, e.g., a loss of plasma control. The code is a hybrid code comprising a zero-dimensional plasma dynamics and a one-dimensional thermal analysis of in-vessel components. The code evaluates the time evolution of plasma parameters and temperature distributions of in-vessel components. As the plasma-safety interface model, we proposed a robust plasma physics model taking into account updated data for safety assessment. For example, physics safety guidelines for beta limit, density limit and H-L mode confinement transition threshold power, etc. are provided in the model. The model of the in-vessel components are divided into twenty temperature regions in the poloidal direction taking account of radiative heat transfer between each surface of each region. This code can also describe the coolant behavior under hydraulic accidents with the results by hydraulics code and treat vaporization (sublimation) from plasma facing components (PFCs). Furthermore, the code includes the model of impurity transport form PFCs by using a transport probability and a time delay. Quantitative analysis based on the model is possible for a scenario of plasma passive shutdown. We examined the possibility of the code as a safety analysis code for plasma anomaly events in fusion reactors and had a prospect that it would contribute to the safety analysis of the International Thermonuclear Experimental Reactor (ITER). (author)

  6. Plasma sprayed TiC coatings for first wall protection in fusion devices

    International Nuclear Information System (INIS)

    Groot, P.; Laan, J.G. van der; Laas, L.; Mack, M.; Dvorak, M.

    1989-01-01

    For protection of plasma facing components in nuclear fusion devices thick titanium carbide coatings are being developed. Coatings have been produced by plasma spraying at atmospheric pressure (APS) and low pressure (LPPS) and analyzed with respect to microstructure and chemical composition. Thermo-mechanical evaluation has been performed by applying short pulse laser heat flux tests. The influence of coating thickness and porosity on the resistance to spalling by thermal shocks appears to be more important than aspects of chemical composition. (author)

  7. Plasma diagnostic techniques in thermal-barrier tandem-mirror fusion experiments

    International Nuclear Information System (INIS)

    Silver, E.H.; Clauser, J.F.; Carter, M.R.; Failor, B.H.; Foote, J.H.; Hornady, R.S.; James, R.A.; Lasnier, C.J.; Perkins, D.E.

    1986-01-01

    We review two classes of plasma diagnostic techniques used in thermal-barrier tandem-mirror fusion experiments. The emphasis of the first class is to study mirror-trapped electrons at the thermal-barrier location. The focus of the second class is to measure the spatial and temporal behavior of the plasma space potential at various axial locations. The design and operation of the instruments in these two categories are discussed and data that are representative of their performance is presented

  8. Gettering high energy plasma in the end loss region of the Mirror Fusion Test Facility

    International Nuclear Information System (INIS)

    Goldner, A.I.; Margolies, D.S.

    1979-01-01

    The ions escaping from the end loss fan of the Mirror Fusion Test Facility (MFTF) neutralize when they hit the surface of the end dome. If the neutrals then bounce back into the oncoming plasma, they are likely to reionize, drawing power from the center of the plasma and reducing the overall electron temperature. In this paper we describe two methods for reducing the reionization rate and a computer code for estimating their effectiveness

  9. Raman-Brillouin interplay for inertial confinement fusion relevant laser–plasma interaction

    Czech Academy of Sciences Publication Activity Database

    Riconda, C.; Weber, Stefan A.

    2016-01-01

    Roč. 4, Jul (2016), 1-16, č. článku e23. ISSN 2095-4719 R&D Projects: GA MŠk EF15_008/0000162 Grant - others:ELI Beamlines(XE) CZ.02.1.01/0.0/0.0/15_008/0000162 Institutional support: RVO:68378271 Keywords : inertial confinement fusion * kinetic effects * laser- plasma interaction Subject RIV: BL - Plasma and Gas Discharge Physics

  10. Review of Burning Plasma Physics. Fusion Energy Sciences Advisory Committee (FESAC)

    International Nuclear Information System (INIS)

    Berk, Herb; Betti, Riccardo; Dahlburg, Jill; Freidberg, Jeff; Hopper, Bick; Meade, Dale; Navritil, Jerry; Nevins, Bill; Ono, Masa; Perkins, Rip; Prager, Stewart; Schoenburg, Kurt; Taylor, Tony; Uckan, Nermin

    2001-01-01

    The next frontier in the quest for magnetic fusion energy is the development of a basic understanding of plasma behavior in the regime of strong self-heating, the so called burning plasma regime. The general consensus in the fusion community is that the exploration of this frontier requires a new, relatively large experimental facility - a burning plasma experiment. The motivation, justification, and steps required to build such a facility are the primary focus of our report. The specific goals of the report are as follows. First, the report describes the critical scientific and engineering phenomena that are expected to arise for the first time, or else in a strongly modified form, in a burning plasma. Second, the report shows that the capabilities of existing experiments are inadequate to investigate these phenomena, thereby providing a major justification for a new facility. Third, the report compares the features and predicted performance of the three major next generation burning plasma experiments under current consideration (ITER-FEAT, FIRE, and IGNITOR), which are aimed at addressing these problems. Deliberately, no selection of the best option is made or attempted since such a decision involves complex scientific and cost issues that are beyond the scope of the present panel report. Fourth, the report makes specific recommendations regarding a process to move the burning plasma program forward, including a procedure for choosing the best option and the future activities of the Next Step Option (NSO) program. Fifth, the report attempts to provide a proper perspective for the role of burning plasmas with respect to the overall U.S. fusion program. The introduction provides the basic background information required for understanding the context in which the U.S. fusion community thinks about burning plasma issues. It sets the stage for the remainder of the report.

  11. One-Dimensional Burn Dynamics of Plasma-Jet Magneto-Inertial Fusion

    Science.gov (United States)

    Santarius, John

    2009-11-01

    This poster will discuss several issues related to using plasma jets to implode a Magneto-Inertial Fusion (MIF) liner onto a magnetized plasmoid and compress it to fusion-relevant temperatures [1]. The problem of pure plasma jet convergence and compression without a target present will be investigated. Cases with a target present will explore how well the liner's inertia provides transient plasma stability and confinement. The investigation uses UW's 1-D Lagrangian radiation-hydrodynamics code, BUCKY, which solves single-fluid equations of motion with ion-electron interactions, PdV work, table-lookup equations of state, fast-ion energy deposition, and pressure contributions from all species. Extensions to the code include magnetic field evolution as the plasmoid compresses plus dependence of the thermal conductivity and fusion product energy deposition on the magnetic field.[4pt] [1] Y.C. F. Thio, et al.,``Magnetized Target Fusion in a Spheroidal Geometry with Standoff Drivers,'' in Current Trends in International Fusion Research, E. Panarella, ed. (National Research Council of Canada, Ottawa, Canada, 1999), p. 113.

  12. X-Pinch Plasma Generation Testing for Neutron Source Development and Nuclear Fusion

    Directory of Open Access Journals (Sweden)

    Hossam A.Gabbar

    2018-04-01

    Full Text Available Nuclear fusion is a sought-out technology in which two light elements are fused together to create a heavier element and releases energy. Two primary nuclear fusion technologies are being researched today: magnetic and inertial confinement. However, a new type of nuclear fusion technology is currently being research: multi-pinch plasma beams. At the University of Ontario Institute of Technology, there is research on multi-pinch plasma beam technology as an alternative to nuclear fusion. The objective is to intersect two plasma arcs at the center of the chamber. This is a precursor of nuclear fusion using multi-pinch. The innovation portion of the students’ work is the miniaturization of this concept using high energy electrical DC pulses. The experiment achieved the temperature of 2300 K at the intersection. In comparison to the simulation data, the temperature from the simulation is 7000 K at the intersection. Additionally, energy harvesting devices, both photovoltaics and a thermoelectric generator, were placed in the chamber to observe the viable energy extraction.

  13. Current fusion plasma theory grant: Task I, Magnetic confinement fusion plasma theory: Final report, December 1, 1987--November 14, 1988

    International Nuclear Information System (INIS)

    Callen, J.D.

    1988-07-01

    The research performed under this grant over the current 11-1/2 month period has concentrated on key tokamak plasma confinement and heating theory issues: extensions of neoclassical MHD; viscosity coefficients and transport; nonlinear resistive MHD simulations of Tokapole II plasmas; ICRF and edge plasma interactions; energy confinement degradation due to macroscopic phenomena; and coordination of a new transport initiative. Progress and publications in these areas are briefly summarized in this report. 21 refs

  14. Deuterium-tritium plasmas in novel regimes in the Tokamak Fusion Test Reactor

    International Nuclear Information System (INIS)

    Bell, M.G.; Beer, M.

    1997-02-01

    Experiments in the Tokamak Fusion Test Reactor (TFTR) have explored several novel regimes of improved tokamak confinement in deuterium-tritium (D-T) plasmas, including plasmas with reduced or reversed magnetic shear in the core and high-current plasmas with increased shear in the outer region (high-l i ). New techniques have also been developed to enhance the confinement in these regimes by modifying the plasma-limiter interaction through in-situ deposition of lithium. In reversed-shear plasmas, transitions to enhanced confinement have been observed at plasma currents up to 2.2 MA (q a ∼ 4.3), accompanied by the formation of internal transport barriers, where large radial gradients develop in the temperature and density profiles. Experiments have been performed to elucidate the mechanism of the barrier formation and its relationship with the magnetic configuration and with the heating characteristics. The increased stability of high-current, high-l i plasmas produced by rapid expansion of the minor cross-section, coupled with improvement in the confinement by lithium deposition has enabled the achievement of high fusion power, up to 8.7 MW, with D-T neutral beam heating. The physics of fusion alpha-particle confinement has been investigated in these regimes, including the interactions of the alphas with endogenous plasma instabilities and externally applied waves in the ion cyclotron range of frequencies. In D-T plasmas with q 0 > 1 and weak magnetic shear in the central region, a toroidal Alfven eigenmode instability driven purely by the alpha particles has been observed for the first time. The interactions of energetic ions with ion Bernstein waves produced by mode-conversion from fast waves in mixed-species plasmas have been studied as a possible mechanism for transferring the energy of the alphas to fuel ions

  15. Atomic and plasma-material interaction data for fusion. V. 14

    International Nuclear Information System (INIS)

    Clark, R.E.H.

    2008-01-01

    Plasmas in fusion energy devices consist of hot core plasmas with cooler regions near the edge. The temperatures are much lower in the edge region than in the core and there is a relatively high population of neutral species. Neutral and charged molecular species may form in this region and influence the plasma diagnostics. A variety of molecules, including species of hydrocarbons, form in the edge region, and hydrocarbon species up to C 3 H 8 may be produced. As the plasma interacts with the surface of the containment vessel, erosion from the surface will take place. There is then the potential for a number of chemical reactions to occur near the surface. A wide variety of interaction processes will take place involving these molecules in the edge region. It is not well known to what extent these processes affect the efficiency of the divertor itself. Thus there is a need to gather spectroscopic and collisional data to better understand the extent to which these processes are important in the edge regions, including data derived from infrared spectroscopy. The importance of these molecular processes to fusion research led to a strong recommendation from the A+M Subcommittee of the International Fusion Research Council at its twelfth meeting in May 2000 to initiate a coordinated research project (CRP) to address data needs in this area. The IAEA initiated the CRP on Data for Molecular Processes in Edge Plasmas in 2001. The purpose of the CRP was to identify the specific molecular processes that are important to the plasma physics in the edge region and to provide data for some of these processes. During the course of the CRP that concluded in 2005, new data have been generated for a variety of processes impacting a number of issues in the edge region of fusion plasmas. Essentially all the goals of the original work plan were fulfilled during the course of the CRP, with the generation of new theoretical and measured cross-sections for a variety of processes in

  16. Explosive-driven hemispherical implosions for generating fusion plasmas

    International Nuclear Information System (INIS)

    Sagie, D.; Glass, I.I.

    1982-03-01

    The UTIAS explosive-driven-implosion facility was used to produce stable, centered and focussed hemispherical implosions to generate neutrons from D-D reactions. A high resolution scintillator-detection system measured the neutrons and γ-rays resulting from the fusion of deuterium. Several approaches were used to initiate fusion in deuterium. The simplest and most direct proved to be in a predetonated stoichiometric mixture of deuterium-oxygen. The other successful method was a miniature Voitenko-type compressor where a plane diaphragm was driven by the implosion wave into a secondary small spherical cavity that contained pure deuterium gas at one atmosphere. A great deal of work still remains in order to measure accurately the neutron flux and its velocity distribution as well as the precise interactions of the neturons with the steel chamber which produced the γ-rays. Nevertheless, this is the only known work where fusion neutrons were produced by chemical energy only in a direct and indirect manner

  17. Generation and compression of a target plasma for magnetized target fusion

    International Nuclear Information System (INIS)

    Kirkpatrick, R.C.; Lindemuth, I.R.; Sheehey, P.T.

    1998-01-01

    This is the final report of a three-year, Laboratory Directed Research and Development (LDRD) project at the Los Alamos National Laboratory (LANL). Magnetized target fusion (MTF) is intermediate between the two very different approaches to fusion: inertial and magnetic confinement fusion (ICF and MCF). Results from collaboration with a Russian MTF team on their MAGO experiments suggest they have a target plasma suitable for compression to provide an MTF proof of principle. This LDRD project had tow main objectives: first, to provide a computational basis for experimental investigation of an alternative MTF plasma, and second to explore the physics and computational needs for a continuing program. Secondary objectives included analytic and computational support for MTF experiments. The first objective was fulfilled. The second main objective has several facets to be described in the body of this report. Finally, the authors have developed tools for analyzing data collected on the MAGO and LDRD experiments, and have tested them on limited MAGO data

  18. Critical plasma-wall interaction issues for plasma-facing materials and components in near-term fusion devices

    International Nuclear Information System (INIS)

    Federici, G.; Coad, J.P.; Haasz, A.A.; Janeschitz, G.; Noda, N.; Philipps, V.; Roth, J.; Skinner, C.H.; Tivey, R.; Wu, C.H.

    2000-01-01

    The increase in pulse duration and cumulative run-time, together with the increase of the plasma energy content, will represent the largest changes in operation conditions in future fusion devices such as the International Thermonuclear Experimental Reactor (ITER) compared to today's experimental facilities. These will give rise to important plasma-physics effects and plasma-material interactions (PMIs) which are only partially observed and accessible in present-day experiments and will open new design, operation and safety issues. For the first time in fusion research, erosion and its consequences over many pulses (e.g., co-deposition and dust) may determine the operational schedule of a fusion device. This paper identifies the most critical issues arising from PMIs which represent key elements in the selection of materials, the design, and the optimisation of plasma-facing components (PFCs) for the first-wall and divertor. Significant advances in the knowledge base have been made recently, as part of the R and D supporting the engineering design activities (EDA) of ITER, and some of the most relevant data are reviewed here together with areas where further R and D work is urgently needed

  19. Review of the works on plasma-wall interactions in fusion reactors, 1

    International Nuclear Information System (INIS)

    Sone, Kazuho

    1975-09-01

    A review is made of the works on sputtering as one of the plasma-wall interactions in thermonuclear fusion devices. The present status and future problems are described mainly in experiments of low-energy light ions such as H + , H 2 + , D + , D 2 + and He + , heavy ions including self-ions, and fast neutrons for polycrystalline metal targets. (auth.)

  20. Plasma physics and controlled nuclear fusion research 1994. V. 3. Proceedings of the fifteenth international conference

    International Nuclear Information System (INIS)

    1996-01-01

    This is the third volume of the proceedings of the 15th International Atomic Energy Agency Conference on Plasma Physics and Controlled Nuclear Fusion Research held in Seville, Spain, from 26 September - 1 October 1994. Contained in it are 29 papers on inertial confinement and 46 papers on magnetic confinement. Refs, figs, tabs

  1. Atomic and plasma-material interaction data for fusion. V.4

    International Nuclear Information System (INIS)

    1993-01-01

    The International Atomic Energy Agency, through its Atomic and Molecular Data Unit, coordinates a wide spectrum of programmes for the compilation, evaluation, and generation of atomic, molecular, and plasma-wall interaction data for fusion research. The present volume is exclusively devoted to cross sections for collisions of hydrogen atoms with electron, protons and multiply charged ions

  2. Ti-doped isotropic graphite: A promising armour material for plasma-facing components

    Science.gov (United States)

    García-Rosales, C.; López-Galilea, I.; Ordás, N.; Adelhelm, C.; Balden, M.; Pintsuk, G.; Grattarola, M.; Gualco, C.

    2009-04-01

    Finely dispersed Ti-doped isotropic graphites with 4 at.% Ti have been manufactured using synthetic mesophase pitch 'AR' as raw material. These new materials show a thermal conductivity at room temperature of ˜200 W/mK and flexural strength close to 100 MPa. Measurement of the total erosion yield by deuterium bombardment at ion energies and sample temperatures for which pure carbon shows maximum values, resulted in a reduction of at least a factor of 4, mainly due to dopant enrichment at the surface caused by preferential erosion of carbon. In addition, ITER relevant thermal shock loads were applied with an energetic electron beam at the JUDITH facility. The results demonstrated a significantly improved performance of Ti-doped graphite compared to pure graphite. Finally, Ti-doped graphite was successfully brazed to a CuCrZr block using a Mo interlayer. These results let assume that Ti-doped graphite can be a promising armour material for divertor plasma-facing components.

  3. Ti-doped isotropic graphite: A promising armour material for plasma-facing components

    Energy Technology Data Exchange (ETDEWEB)

    Garcia-Rosales, C. [CEIT and Tecnun (University of Navarra), Paseo de Manuel Lardizabal, 15, E-20018 San Sebastian (Spain)], E-mail: cgrosales@ceit.es; Lopez-Galilea, I.; Ordas, N. [CEIT and Tecnun (University of Navarra), Paseo de Manuel Lardizabal, 15, E-20018 San Sebastian (Spain); Adelhelm, C.; Balden, M. [Max-Planck-Institut fuer Plasmaphysik, EURATOM Association, D-85748 Garching (Germany); Pintsuk, G. [Forschungszentrum Juelich GmbH, EURATOM Association, D-52425 Juelich (Germany); Grattarola, M.; Gualco, C. [Ansaldo Ricerche S.p.A., I-16152 Genoa (Italy)

    2009-04-30

    Finely dispersed Ti-doped isotropic graphites with 4 at.% Ti have been manufactured using synthetic mesophase pitch 'AR' as raw material. These new materials show a thermal conductivity at room temperature of {approx}200 W/mK and flexural strength close to 100 MPa. Measurement of the total erosion yield by deuterium bombardment at ion energies and sample temperatures for which pure carbon shows maximum values, resulted in a reduction of at least a factor of 4, mainly due to dopant enrichment at the surface caused by preferential erosion of carbon. In addition, ITER relevant thermal shock loads were applied with an energetic electron beam at the JUDITH facility. The results demonstrated a significantly improved performance of Ti-doped graphite compared to pure graphite. Finally, Ti-doped graphite was successfully brazed to a CuCrZr block using a Mo interlayer. These results let assume that Ti-doped graphite can be a promising armour material for divertor plasma-facing components.

  4. Ti-doped isotropic graphite: A promising armour material for plasma-facing components

    International Nuclear Information System (INIS)

    Garcia-Rosales, C.; Lopez-Galilea, I.; Ordas, N.; Adelhelm, C.; Balden, M.; Pintsuk, G.; Grattarola, M.; Gualco, C.

    2009-01-01

    Finely dispersed Ti-doped isotropic graphites with 4 at.% Ti have been manufactured using synthetic mesophase pitch 'AR' as raw material. These new materials show a thermal conductivity at room temperature of ∼200 W/mK and flexural strength close to 100 MPa. Measurement of the total erosion yield by deuterium bombardment at ion energies and sample temperatures for which pure carbon shows maximum values, resulted in a reduction of at least a factor of 4, mainly due to dopant enrichment at the surface caused by preferential erosion of carbon. In addition, ITER relevant thermal shock loads were applied with an energetic electron beam at the JUDITH facility. The results demonstrated a significantly improved performance of Ti-doped graphite compared to pure graphite. Finally, Ti-doped graphite was successfully brazed to a CuCrZr block using a Mo interlayer. These results let assume that Ti-doped graphite can be a promising armour material for divertor plasma-facing components.

  5. Atomic and plasma-material interaction data for fusion. Vol. 13

    International Nuclear Information System (INIS)

    Clark, R.E.H.

    2007-01-01

    Plasmas generated in fusion energy research cover a wide range of conditions involving electron temperature, electron density and plasma constituents, as well as electric and magnetic fields. Performing diagnostics on such plasmas is a complex problem requiring many different types of atomic and molecular (A+M) data. The typical plasmas in fusion research naturally divide into a core region and an edge/divertor region, and the physical conditions differ significantly between these two regions. There is a need to use soft X-ray spectroscopy as well as optical spectroscopy for diagnostics in the core region. This requires information on the emission properties of the plasma under the core conditions. Information about several different processes for atomic species relevant to the plasma is needed in this process. Some data can be measured directly in experimental devices such as the electron beam ion trap (EBIT). This type of measurement would prove very useful in furthering databases for plasma diagnostics of core regions. Heating beams are used to raise the core temperature and doped beams are used for diagnostic purposes. Thus, beam spectroscopy is an important consideration in the core region. Radiation from impurities in the edge region is very important in understanding the formation of advanced discharge regimes (transport barriers). Temperatures are significantly lower in the edge/ divertor region and there is a relatively high population of neutral species. Molecules will also form in this region, requiring extensive data on a variety of molecular processes for diagnostic procedures. Processes such as charge exchange will also be important for diagnostic purposes in the edge - data needed for diagnostics include radiative as well as collision processes. Collision processes include both electron and heavy particle collisions. The importance of generating new data for support of diagnostics in fusion plasmas led to a strong recommendation at the 12th meeting

  6. Development of Laser Based Plasma Diagnostics for Fusion Research on NSTX-U

    Science.gov (United States)

    Barchfeld, Robert Adam

    Worldwide demand for power, and in particular electricity, is growing. Increasing population, expanding dependence on electrical devices, as well as the development of emerging nations, has created significant challenges for the power production. Compounding the issue are concerns over pollution, natural resource supplies, and political obstacles in troubled parts of the world. Many believe that investment in renewable energy will solve the expected energy crisis; however, renewable energy has many shortfalls. Consequently, additional sources of energy should be explored to provide the best options for the future. Electricity from fusion power offers many advantages over competing technologies. It can potentially produce large amounts of clean energy, without the serious concerns of fission power plant safety and nuclear waste. Fuel supplies for fusion are plentiful. Fusion power plants can be operated as needed, without dependence on location, or local conditions. However, there are significant challenges before fusion can be realized. Many factors currently limit the effectiveness of fusion power, which prevents a commercial power plant from being feasible. Scientists in many countries have built, and operate, experimental fusion plants to study the fusion process. The leading examples are magnetic confinement reactors known as tokamaks. At present, reactor gain is near unity, where the fusion power output is nearly the same as the power required to operate the reactor. A tenfold increase in gain is what reactors such as ITER hope to achieve, where 50 MW will be used for plasma heating, magnetic fields, and so forth, with a power output of 500 MW. Before this can happen, further research is required. Loss of particle and energy confinement is a principal cause of low performance; therefore, increasing confinement time is key. There are many causes of thermal and particle transport that are being researched, and the prime tools for conducting this research are

  7. Fusion spectroscopy

    International Nuclear Information System (INIS)

    Peacock, N.J.

    1995-09-01

    This article traces developments in the spectroscopy of high temperature laboratory plasma used in controlled fusion research from the early 1960's until the present. These three and a half decades have witnessed many orders of magnitude increase in accessible plasma parameters such as density and temperature as well as particle and energy confinement timescales. Driven by the need to interpret the radiation in terms of the local plasma parameters, the thrust of fusion spectroscopy has been to develop our understanding of (i) the atomic structure of highly ionised atoms, usually of impurities in the hydrogen isotope fuel; (ii) the atomic collision rates and their incorporation into ionization structure and emissivity models that take into account plasma phenomena like plasma-wall interactions, particle transport and radiation patterns; (iii) the diagnostic applications of spectroscopy aided by increasingly sophisticated characterisation of the electron fluid. These topics are discussed in relation to toroidal magnetically confined plasmas, particularly the Tokamak which appears to be the most promising approach to controlled fusion to date. (author)

  8. Preface to Special Topic: Advances in Radio Frequency Physics in Fusion Plasmas

    International Nuclear Information System (INIS)

    Tuccillo, Angelo A.; Ceccuzzi, Silvio; Phillips, Cynthia K.

    2014-01-01

    It has long been recognized that auxiliary plasma heating will be required to achieve the high temperature, high density conditions within a magnetically confined plasma in which a fusion “burn” may be sustained by copious fusion reactions. Consequently, the application of radio and microwave frequency electromagnetic waves to magnetically confined plasma, commonly referred to as RF, has been a major part of the program almost since its inception in the 1950s. These RF waves provide heating, current drive, plasma profile control, and Magnetohydrodynamics (MHD) stabilization. Fusion experiments employ electromagnetic radiation in a wide range of frequencies, from tens of MHz to hundreds of GHz. The fusion devices containing the plasma are typically tori, axisymmetric or non, in which the equilibrium magnetic fields are composed of a strong toroidal magnetic field generated by external coils, and a poloidal field created, at least in the symmetric configurations, by currents flowing in the plasma. The waves are excited in the peripheral regions of the plasma, by specially designed launching structures, and subsequently propagate into the core regions, where resonant wave-plasma interactions produce localized heating or other modification of the local equilibrium profiles. Experimental studies coupled with the development of theoretical models and advanced simulation codes over the past 40+ years have led to an unprecedented understanding of the physics of RF heating and current drive in the core of magnetic fusion devices. Nevertheless, there are serious gaps in our knowledge base that continue to have a negative impact on the success of ongoing experiments and that must be resolved as the program progresses to the next generation devices and ultimately to “demo” and “fusion power plant.” A serious gap, at least in the ion cyclotron (IC) range of frequencies and partially in the lower hybrid frequency ranges, is the difficulty in coupling large amount of

  9. Preface to Special Topic: Advances in Radio Frequency Physics in Fusion Plasmas

    Science.gov (United States)

    Tuccillo, Angelo A.; Phillips, Cynthia K.; Ceccuzzi, Silvio

    2014-06-01

    It has long been recognized that auxiliary plasma heating will be required to achieve the high temperature, high density conditions within a magnetically confined plasma in which a fusion "burn" may be sustained by copious fusion reactions. Consequently, the application of radio and microwave frequency electromagnetic waves to magnetically confined plasma, commonly referred to as RF, has been a major part of the program almost since its inception in the 1950s. These RF waves provide heating, current drive, plasma profile control, and Magnetohydrodynamics (MHD) stabilization. Fusion experiments employ electromagnetic radiation in a wide range of frequencies, from tens of MHz to hundreds of GHz. The fusion devices containing the plasma are typically tori, axisymmetric or non, in which the equilibrium magnetic fields are composed of a strong toroidal magnetic field generated by external coils, and a poloidal field created, at least in the symmetric configurations, by currents flowing in the plasma. The waves are excited in the peripheral regions of the plasma, by specially designed launching structures, and subsequently propagate into the core regions, where resonant wave-plasma interactions produce localized heating or other modification of the local equilibrium profiles. Experimental studies coupled with the development of theoretical models and advanced simulation codes over the past 40+ years have led to an unprecedented understanding of the physics of RF heating and current drive in the core of magnetic fusion devices. Nevertheless, there are serious gaps in our knowledge base that continue to have a negative impact on the success of ongoing experiments and that must be resolved as the program progresses to the next generation devices and ultimately to "demo" and "fusion power plant." A serious gap, at least in the ion cyclotron (IC) range of frequencies and partially in the lower hybrid frequency ranges, is the difficulty in coupling large amount of power to the

  10. A two photon absorption laser induced fluorescence diagnostic for fusion plasmas

    Energy Technology Data Exchange (ETDEWEB)

    Magee, R. M.; Galante, M. E.; McCarren, D.; Scime, E. E. [Physics Department, West Virginia University, Morgantown, West Virginia 26506 (United States); Boivin, R. L.; Brooks, N. H.; Groebner, R. J.; Hill, D. N. [General Atomics, San Diego, California 92121 (United States); Porter, G. D. [Lawrence Livermore National Laboratory, Livermore, California 94550 (United States)

    2012-10-15

    The quality of plasma produced in a magnetic confinement fusion device is influenced to a large extent by the neutral gas surrounding the plasma. The plasma is fueled by the ionization of neutrals, and charge exchange interactions between edge neutrals and plasma ions are a sink of energy and momentum. Here we describe a diagnostic capable of measuring the spatial distribution of neutral gas in a magnetically confined fusion plasma. A high intensity (5 MW/cm{sup 2}), narrow bandwidth (0.1 cm{sup -1}) laser is injected into a hydrogen plasma to excite the Lyman {beta} transition via the simultaneous absorption of two 205 nm photons. The absorption rate, determined by measurement of subsequent Balmer {alpha} emission, is proportional to the number of particles with a given velocity. Calibration is performed in situ by filling the chamber to a known pressure of neutral krypton and exciting a transition close in wavelength to that used in hydrogen. We present details of the calibration procedure, including a technique for identifying saturation broadening, measurements of the neutral density profile in a hydrogen helicon plasma, and discuss the application of the diagnostic to plasmas in the DIII-D tokamak.

  11. A two photon absorption laser induced fluorescence diagnostic for fusion plasmas.

    Science.gov (United States)

    Magee, R M; Galante, M E; McCarren, D; Scime, E E; Boivin, R L; Brooks, N H; Groebner, R J; Hill, D N; Porter, G D

    2012-10-01

    The quality of plasma produced in a magnetic confinement fusion device is influenced to a large extent by the neutral gas surrounding the plasma. The plasma is fueled by the ionization of neutrals, and charge exchange interactions between edge neutrals and plasma ions are a sink of energy and momentum. Here we describe a diagnostic capable of measuring the spatial distribution of neutral gas in a magnetically confined fusion plasma. A high intensity (5 MW/cm(2)), narrow bandwidth (0.1 cm(-1)) laser is injected into a hydrogen plasma to excite the Lyman β transition via the simultaneous absorption of two 205 nm photons. The absorption rate, determined by measurement of subsequent Balmer α emission, is proportional to the number of particles with a given velocity. Calibration is performed in situ by filling the chamber to a known pressure of neutral krypton and exciting a transition close in wavelength to that used in hydrogen. We present details of the calibration procedure, including a technique for identifying saturation broadening, measurements of the neutral density profile in a hydrogen helicon plasma, and discuss the application of the diagnostic to plasmas in the DIII-D tokamak.

  12. CONFERENCE DESCRIPTION Theory of Fusion Plasmas: Varenna-Lausanne International Workshop

    Science.gov (United States)

    Garbet, X.; Sauter, O.

    2010-12-01

    The Joint Varenna-Lausanne international workshop on Theory of Fusion Plasmas takes place every other year in a place particularly favourable for informal and in-depth discussions. Invited and contributed papers present state-of-the-art research in theoretical plasma physics, covering all domains relevant to fusion plasmas. This workshop always welcomes a fruitful mix of experienced researchers and students, to allow a better understanding of the key theoretical physics models and applications. Theoretical issues related to burning plasmas Anomalous Transport (Turbulence, Coherent Structures, Microinstabilities) RF Heating and Current Drive Macroinstabilities Plasma-Edge Physics and Divertors Fast particles instabilities Further details: http://Varenna-Lausanne.epfl.ch The conference is organized by: Centre de Recherches en Physique des Plasmas, Ecole Polytechnique Fédérale de Lausanne, Association EURATOM - Confédération Suisse 'Piero Caldirola' International Centre for the Promotion of Science and International School of Plasma Physics Istituto di Fisica del Plasma del CNR, Milano Editors: X Garbet (CEA, Cadarache, France) and O Sauter (CRPP-EPFL, Lausanne, Switzerland)

  13. Development of a Plasma Streaming System for the Mirror Fusion Test Facility

    International Nuclear Information System (INIS)

    Holdsworth, T.; Clark, R.N.; McCotter, R.E.; Rossow, T.L.; Cruz, G.E.

    1979-01-01

    The Plasma Streaming System (PSS) is an essential portion of the Mirror Fusion Test Facility (MFTF), scheduled for completion in October 1981. The PSS will develop a plasma density of at least 2 x 10 12 particles/cm 3 at the MFTF magnet centerline by injecting particles along the field lines. The plasma will have a midplane plasma radius as large as 40 cm with variable plasma particle energy and beam geometry. Minimum amounts of impurities will be injected, with emphasis on minimizing high Z materials. Each of the 60 PSS units will consist of a gun magnet assembly (GMA) and a power supply. Each GMA consists of a plasma streaming gun, a pulse magnet that provides variable beam shaping, and a fast reaction pulse gas valve

  14. Safety analyses for transient behavior of plasma and in-vessel components during plasma abnormal events in fusion reactor

    International Nuclear Information System (INIS)

    Honda, Takuro; Okazaki, Takashi; Bartels, H.W.; Uckan, N.A.; Seki, Yasushi.

    1997-01-01

    Safety analyses on plasma abnormal events have been performed using a hybrid code of a plasma dynamics model and a heat transfer model of in-vessel components. Several abnormal events, e.g., increase in fueling rate, were selected for the International Thermonuclear Experimental Reactor (ITER) and transient behavior of the plasma and the invessel components during the events was analyzed. The physics model for safety analysis was conservatively prepared. In most cases, the plasma is terminated by a disruption or it returns to the original operation point. When the energy confinement improves by a factor of 2.0 in the steady state, which is a hypothetical assumption under the present plasma data, the maximum fusion power reaches about 3.3 GW at about 3.6 s and the plasma is terminated due to a disruption. However, the results obtained in this study show the confinement boundary of ITER can be kept almost intact during the abnormal plasma transients, as long as the cooling system works normally. Several parametric studies are needed to comprehend the overpower transient including structure behavior, since many uncertainties are connected to the filed of the plasma physics. And, future work will need to discuss the burn control scenario considering confinement mode transition, system specifications, experimental plans and safety regulations, etc. to confirm the safety related to the plasma anomaly. (author)

  15. Fusion

    CERN Document Server

    Mahaffey, James A

    2012-01-01

    As energy problems of the world grow, work toward fusion power continues at a greater pace than ever before. The topic of fusion is one that is often met with the most recognition and interest in the nuclear power arena. Written in clear and jargon-free prose, Fusion explores the big bang of creation to the blackout death of worn-out stars. A brief history of fusion research, beginning with the first tentative theories in the early 20th century, is also discussed, as well as the race for fusion power. This brand-new, full-color resource examines the various programs currently being funded or p

  16. Energetic particle physics with applications in fusion and space plasmas

    International Nuclear Information System (INIS)

    Cheng, C.Z.

    1997-01-01

    Energetic particle physics is the study of the effects of energetic particles on collective electromagnetic (EM) instabilities and energetic particle transport in plasmas. Anomalously large energetic particle transport is often caused by low frequency MHD instabilities, which are driven by these energetic particles in the presence of a much denser background of thermal particles. The theory of collective energetic particle phenomena studies complex wave-particle interactions in which particle kinetic physics involving small spatial and fast temporal scales can strongly affect the MHD structure and long-time behavior of plasmas. The difficulty of modeling kinetic-MHD multiscale coupling processes stems from the disparate scales which are traditionally analyzed separately: the macroscale MHD phenomena are studied using the fluid MHD framework, while microscale kinetic phenomena are best described by complicated kinetic theories. The authors have developed a kinetic-MHD model that properly incorporates major particle kinetic effects into the MHD fluid description. For tokamak plasmas a nonvariational kinetic-MHD stability code, the NOVA-K code, has been successfully developed and applied to study problems such as the excitation of fishbone and Toroidal Alfven Eigenmodes (TAE) and the sawtooth stabilization by energetic ions in tokamaks. In space plasmas the authors have employed the kinetic-MHD model to study the energetic particle effects on the ballooning-mirror instability which explains the multisatellite observation of the stability and field-aligned structure of compressional Pc 5 waves in the magnetospheric ring current plasma

  17. Possible further subjects of study in the field of fusion plasma theory in Latvia

    International Nuclear Information System (INIS)

    Dumbrajs, O.

    2004-01-01

    Full text: First fusion plasma theory relevant studies in Latvia were related to edge localized modes (ELMs). This work has been carried out at the Institute of Solid Physics and is nearing successful completion. The next suggested topic 'Stochastisation of magnetic field lines and its impact on fusion plasma' is related to the theory of ergotic magnetic fields. The stochastisation of magnetic field lines is thought to play a major role in fast energy loss events from magnetically confined fusion plasma due to magnetohydrodynamic (MHD) modes. Classical examples are sawtooth crashes and disruptions. Here it is thought that stochastisation plays a role in the enhanced reconnection rate, which is often observed. More recently, this process has also been proposed as an explanation for the neoclassical tearing modes (NTM) phenomenon, which is repetitive rapid decrease of a neoclassical magnetic island due to its interaction with other MHD modes. The timescale for this phenomenon is clearly too fast to be explained by a conventional reconnection. The theoretical study of the onset of stochastisation will be illustrated for plasma parameters typical for the ASDEX Upgrade tokamak operated at the Max-Planc-Institute for Plasma Physics in Garching, Germany

  18. Progress report 1990/91 of the Division of Fusion Plasma Physics

    International Nuclear Information System (INIS)

    Lehnert, B.

    1991-08-01

    A summary is given of the historical background, research, education and available resources of the Division of Fusion Plasma Physics at the newly established Alfven Laboratory. Experimental and theoretical research is performed, including basic physics of magnetized plasma as well as applications to magnetically confined fusion plasma, and to certain technical and cosmical problems. The major project consists of the 'Extrap' high-beta confinement scheme within which a large experimental facility, EXTRAP T2, is under preparation. This research is performed in terms of extensive international collaboration and commitments, in particular with the European Community (Euratom). The education includes pregraduate and postgraduate teaching, the latter being based on obligatory, optional and extra courses which are connected with the research activities

  19. Nonthermal fusion reactor concept based on Hall-effect magnetohydrodynamics plasma theory

    International Nuclear Information System (INIS)

    Witalis, E.A.

    1988-01-01

    The failure of magnetic confinement controlled thermonuclear fusion research to achieve its goal is attributed to its foundation on the incomplete MHD plasma description instead of the more general HMHD (Hall-effect magnetohydrodynamics) theory. The latter allows for a certain magnetic plasma self-confinement under described stringent conditions. A reactor concept based on the formation, acceleration, and forced disintegration of magnetized whirl structures, plasmoids, is proposed. The four conventional MHD theory objections, i.e., absence of dynamo action, fast decay caused by resistivity, non-existence of magnetic self-confinement, and negligible non-thermal fusion yield, are shown not to apply. Support for the scheme from dense plasma focus research is pointed out. (orig.) [de

  20. Educational Outreach at the M.I.T. Plasma Fusion Center

    Science.gov (United States)

    Censabella, V.

    1996-11-01

    Educational outreach at the MIT Plasma Fusion Center consists of volunteers working together to increase the public's knowledge of fusion and plasma-related experiments. Seeking to generate excitement about science, engineering and mathematics, the PFC holds a number of outreach activities throughout the year, such as Middle and High School Outreach Days. Outreach also includes the Mr. Magnet Program, which uses an interactive strategy to engage elementary school children. Included in this year's presentation will be a new and improved C-MOD Jr, a confinement video game which helps students to discover how computers manipulate magnetic pulses to keep a plasma confined for as long as possible. Also on display will be an educational toy created by the Cambridge Physics Outlet, a PFC spin-off company. The PFC maintains a Home Page on the World Wide Web, which can be reached at http://cmod2.pfc.mit.edu/.

  1. Classical impurity ion confinement in a toroidal magnetized fusion plasma.

    Science.gov (United States)

    Kumar, S T A; Den Hartog, D J; Caspary, K J; Magee, R M; Mirnov, V V; Chapman, B E; Craig, D; Fiksel, G; Sarff, J S

    2012-03-23

    High-resolution measurements of impurity ion dynamics provide first-time evidence of classical ion confinement in a toroidal, magnetically confined plasma. The density profile evolution of fully stripped carbon is measured in MST reversed-field pinch plasmas with reduced magnetic turbulence to assess Coulomb-collisional transport without the neoclassical enhancement from particle drift effects. The impurity density profile evolves to a hollow shape, consistent with the temperature screening mechanism of classical transport. Corroborating methane pellet injection experiments expose the sensitivity of the impurity particle confinement time to the residual magnetic fluctuation amplitude.

  2. Plasma Physics and Controlled Nuclear Fusion Research. Vol. II. Proceedings of a Conference on Plasma Physics and Controlled Physics Research

    International Nuclear Information System (INIS)

    1966-01-01

    Research on controlled nuclear fusion was first disclosed at the Second United Nations Conference on the Peaceful Uses of Atomic Energy, held at Geneva in 1958. From the information given, it was evident that a better understanding of the behaviour of hot dense plasmas was needed before the goal of economic energy release from nuclear fusion could be reached. The fact that research since then has been most complex and costly has enhanced the desirability of international co-operation and exchange of information and experience. Having organized its First Conference on Plasma Physics and Controlled Nuclear Fusion Research at Salzburg in 1961, the International Atomic Energy Agency again provided the means for such cooperation in organizing its Second Conference on this subject on 6-10 September, 1965, at Culham, Abingdon, Berks, England. The meeting was arranged with the generous help of the United Kingdom Atomic Energy Authority at their Culham Laboratory, where the facilities and assistance of the staff were greatly appreciated. At the meeting, which was attended by 268 participants from 26 member states and three international organizations, significant results from many experiments, including those from the new and larger machines, became available. It has now become feasible to intercorrelate data obtained from a number of similar machines; this has led to a more complete understanding of plasma behaviour. No breakthrough was reported nor had been expected towards the economical release of the energy from fusion, but there was increased understanding of the problems of production, control and containment of high-density and high-temperature plasmas

  3. Atomic physics for fusion plasma spectroscopy; a soft x-ray study of molybdenum ions

    International Nuclear Information System (INIS)

    Fournier, K.B.

    1996-01-01

    Understanding the radiative patterns of the ions of heavy atoms (Z approx-gt 18) is crucial to fusion experiments. The present thesis applies ab initio, relativistic calculations of atomic data to modeling the emission of molybdenum (Z = 42) ions in magnetically confined fusion plasmas. The models are compared to observations made in the Alcator C-Mod tokamak (Plasma Fusion Center, Massachusetts Institute of Technology), and the Frascati Tokamak Upgrade. Experimental confirmation of these models allows confidence in calculations of the total molybdenum concentration and quantitative estimates of the total power lost from the plasmas due to molybdenum line radiation. Charge states in the plasma core (Mo 33+ to Mo 29+ ) emit strong x-ray and XUV spectra which allow benchmarking of models for the spatial distribution of highly stripped molybdenum ions; the models only achieve agreement with observations when the rates of indirect ionization and recombination processes are included in the calculation of the charge state distribution of the central molybdenum ions. The total concentration of molybdenum in the core of the plasma is found, and the total power radiated from the plasma core is computed. Observations of line emission from more highly charged molybdenum ions (Mo 36+ to Mo 34+ ) are presented. open-quotes Bulkclose quotes molybdenum charge states (Mo 25+ to Mo 23+ ) emit complicated XUV spectra from a position in the plasma near C-Mod's half radius; spatial profiles of these ions' emission are analyzed. Models for the line-emission spectra of adjacent ions (Mo 28+ to Mo 26+ ) are offered, and the accuracy and limits of ab initio energy level calculations are discussed. open-quotes Edgeclose quotes charge states (Mo 22+ to Mo 15 ) extend to the last closed magnetic flux surface of the C-Mod plasma. The strongest features from these charge states are emitted in a narrow band from ∼70 Angstrom

  4. Spectra of heliumlike krypton from tokamak fusion test reactor plasmas

    International Nuclear Information System (INIS)

    Bitter, M.; Hsuan, H.; Bush, C.; Cohen, S.; Cummings, C.J.; Grek, B.; Hill, K.W.; Schivell, J.; Zarnstorff, M.; Smith, A.; Fraenkel, B.

    1993-04-01

    Krypton has been injected into ohmically-heated TFTR plasmas with peak electron temperatures of 6 key to study the effects of krypton on the plasma performance and to investigate the emitted krypton line radiation, which is of interest for future-generation tokamaks such as ITER, both as a diagnostic of the central ion temperature and for the control of energy release from the plasma by radiative cooling. The emitted radiation was monitored with a bolometer array, an X-ray pulse height analysis system, and a high-resolution Johann-type crystal spectrometer; and it was found to depend very sensitively on the electron temperature profile. Satellite spectra of heliumlike krypton, KrXXXV, near 0.95 Angstrom including lithiumlike, berylliumlike and boronlike features were recorded in second order Bragg reflection. Radiative cooling and reduced particle recycling at the plasma edge region were observed as a result of the krypton injection for all investigated discharges. The observations are in reasonable agreement with modeling calculations of the krypton ion charge state distribution including radial transport

  5. Simulation of transition dynamics to high confinement in fusion plasmas

    DEFF Research Database (Denmark)

    Nielsen, Anders Henry; Xu, G. S.; Madsen, Jens

    2015-01-01

    The transition dynamics from the low (L) to the high (H) confinement mode in magnetically confined plasmas is investigated using a first-principles four-field fluid model. Numerical results are in agreement with measurements from the Experimental Advanced Superconducting Tokamak - EAST...

  6. Neutron degradation of UV enhanced optical fibers for fusion installation plasma diagnostics

    International Nuclear Information System (INIS)

    Sporea, D.; Vata, I.; Dudu, D.; Danis, Ana

    2004-01-01

    The remote diagnostics of plasmas in fusion installations requires adequate connection links to transfer the measured signals in media subjected to high electromagnetic disturbances. We evaluated the neutron irradiation induced optical absorption in several commercially available optical fibers, as they were assessed for their possible use in fusion installations. Optical fiber samples were subjected to subsequent irradiation with fluences from 6 x 10 11 to 6 x 10 13 n/cm 2 . Significant radiation induced absorption was observed in the 220-260 nm spectral band, mainly for small core diameter optical fibers (200/220 μm), independent of the cladding material used

  7. Consideration on nuclear fusion in plasma by the magnetic confinement as a heat engine

    International Nuclear Information System (INIS)

    Tsuji, Yoshio

    1990-01-01

    In comparing nuclear fusion in plasma by the magnetic confinement with nuclear fission and chemical reactions, the power density and the function of a heat engine are discussed using a new parameter G introduced as an eigenvalue of a reaction and the value of q introduced to estimate the thermal efficiency of a heat engine. It is shown that the fusion reactor by the magnetic confinement is very difficult to be a modern heat engine because of the lack of some indispensable functions as a modern heat engine. The value of G and q have the important role in the consideration. (author)

  8. An effect of nuclear electric quadrupole moments in thermonuclear fusion plasmas

    Science.gov (United States)

    De, B. R.; Srnka, L. J.

    1978-01-01

    Consideration of the nuclear electric quadrupole terms in the expression for the fusion Coulomb barrier suggests that this electrostatic barrier may be substantially modified from that calculated under the usual plasma assumption that the nuclei are electric monopoles. This effect is a result of the nonspherical potential shape and the spatial quantization of the nuclear spins of the fully stripped ions in the presence of a magnetic field. For monopole-quadrupole fuel cycles like p-B-11, the fusion cross-section may be substantially increased at low energies if the protons are injected at a small angle relative to the confining magnetic field.

  9. Participation of the Instituto de Pesquisas Espaciais in the national program for plasma physics and controlled thermonuclear fusion

    International Nuclear Information System (INIS)

    1990-01-01

    This is a report concerning the participation of the Instituto de Pesquisas Espaciais in the national program for plasma physics and controlled thermonuclear fusion. The report lists all the personnel enroled in research activities, both theoretical and experimental. The research subjects are the following: relativistic electron beams; plasma produced by laser; plasma theory; quiescent plasma; plasma centrifugal; ionic propulsion. (A.C.A.S.) [pt

  10. Plasma Surface Interactions Common to Advanced Fusion Wall Materials and EUV Lithography - Lithium and Tin

    Science.gov (United States)

    Ruzic, D. N.; Alman, D. A.; Jurczyk, B. E.; Stubbers, R.; Coventry, M. D.; Neumann, M. J.; Olczak, W.; Qiu, H.

    2004-09-01

    Advanced plasma facing components (PFCs) are needed to protect walls in future high power fusion devices. In the semiconductor industry, extreme ultraviolet (EUV) sources are needed for next generation lithography. Lithium and tin are candidate materials in both areas, with liquid Li and Sn plasma material interactions being critical. The Plasma Material Interaction Group at the University of Illinois is leveraging liquid metal experimental and computational facilities to benefit both fields. The Ion surface InterAction eXperiment (IIAX) has measured liquid Li and Sn sputtering, showing an enhancement in erosion with temperature for light ion bombardment. Surface Cleaning of Optics by Plasma Exposure (SCOPE) measures erosion and damage of EUV mirror samples, and tests cleaning recipes with a helicon plasma. The Flowing LIquid surface Retention Experiment (FLIRE) measures the He and H retention in flowing liquid metals, with retention coefficients varying between 0.001 at 500 eV to 0.01 at 4000 eV.

  11. Teaching and research in fusion plasmas and technology at the University of Illinois

    International Nuclear Information System (INIS)

    Miley, G.H.; Southworth, F.H.

    1975-01-01

    Teaching in fusion at the University of Illinois is an integrated part of the nuclear engineering curriculum. Through the use of two key courses, ''Introduction to Fusion'' and ''Fusion Systems,'' basic preparation for those wishing to specialize in fusion is provided. These courses are primarily directed to plasma aspects of fusion, but materials and other engineering aspects have been integrated into the curriculum through a broadened coverage in such existing courses as nuclear materials, shielding, and reactor physics. Research is primarily focused at the PhD level, although some MS studies are in progress. While current theses involve a wide variety of topics, one major area being pursued is the study of advanced fuel (non-deuterium-tritium) reactors based on two-component fusion and other concepts. This effort consists of a series of loosely knit subtasks related to such problems as cyclotron emission and direct energy conversion. Also, various research involving charge-exchange losses during neutral-beam injection, vacuum-wall sputtering, and related topics has developed as a direct outgrowth of the PROMETHEUS project, which involved the conceptual design of a power-consuming mirror-type reactor for materials and engineering tests

  12. H-1NF: Australian national fusion plasma research facility

    International Nuclear Information System (INIS)

    Blackwell, B.D.; Borg, G.G.; Dewar, R.L.; Howard, J.; Gardner, H.J.; Rudakov, D.L.; Sharp, L.E.; Shats, M.G.; Warr, G.B.

    1997-01-01

    The H-1 heliac is a helical axis stellarator of moderate size and novel, flexible configuration. Since commissioning, H-1 has operated in quasi-continuous mode at low magnetic field. For higher fields ≤1T an ECRH heating system (28GHz, 200kW) has been installed under a collaborative agreement between ANU and NIFS. H-1 has recently been promoted to national facility status (H-1NF), which will include upgrades of the rf and ech heating systems to megawatt powers, and power supply and diagnostic and data system enhancements. This facilitates collaborative research locally (through the Australian Fusion Research Group consortium) and internationally. Results of a number of basic experiments in quasi-continuous mode are presented. (author)

  13. High-density-plasma diagnostics in magnetic-confinement fusion

    International Nuclear Information System (INIS)

    Jahoda, F.C.

    1982-01-01

    The lectures will begin by defining high density in the context of magnetic confinement fusion research and listing some alternative reactor concepts, ranging from n/sub e/ approx. 2 x 10 14 cm -3 to several orders of magnitude greater, that offer potential advantages over the main-line, n/sub e/ approx. 1 x 10 14 cm -3 , Tokamak reactor designs. The high density scalings of several major diagnostic techniques, some favorable and some disadvantageous, will be discussed. Special emphasis will be given to interferometric methods, both electronic and photographic, for which integral n/sub e/dl measurements and associated techniques are accessible with low wavelength lasers. Reactor relevant experience from higher density, smaller dimension devices exists. High density implies high β, which implies economies of scale. The specialized features of high β diagnostics will be discussed

  14. Pulse compression radar reflectometry for density measurements on fusion plasmas

    Energy Technology Data Exchange (ETDEWEB)

    Costley, A; Prentice, R [Commission of the European Communities, Abingdon (United Kingdom). JET Joint Undertaking; Laviron, C [Compagnie Generale des Matieres Nucleaires (COGEMA), 78 - Velizy-Villacoublay (France); Prentice, R [Toulouse-3 Univ., 31 (France). Centre d` Etude Spatiale des Rayonnements

    1994-07-01

    On tokamaks and other toroidal machines, reflectometry is a very rapidly developing technique for density profile measurements, particularly near the edge. Its principle relies on the total reflection of an electromagnetic wave at a cutoff layer, where the critical density is reached and the local refractive index goes to zero. With the new fast frequency synthesizers now available, a method based on pulse compression radar is proposed for plasma reflectometry, overcoming the limitations of the previous reflectometry methods. The measurement can be made on a time-scale which is effectively very short relatively to the plasma fluctuations, and the very high reproducibility and stability of the source allows an absolute calibration of the waveguides to be made, which corrects for the effects of the parasitic reflections. 2 refs., 5 figs.

  15. Fluctuations and transport in fusion plasmas. Final report

    International Nuclear Information System (INIS)

    Gould, R.W.; Liewer, P.C.

    1995-01-01

    The energy confinement in tokamaks in thought to be limited by transport caused by plasma turbulence. Three dimensional plasma particle-in-cell (PIC) codes are used to model the turbulent transport in tokamaks to attempt to understand this phenomena so that tokamaks can be made more efficient. Presently, hundreds of hours of Cray time are used to model these experiments and much bigger and longer runs are desired, to model a large tokamak with realistic parameters is beyond the capability of existing sequential supercomputers. Parallel supercomputers might be a cost effect tool for performing such large scale 3D tokamak simulations. The goal of the work was to develop algorithms for performing PIC codes on coarse-grained message passing parallel computers and to evaluate the performance of such parallel computers on PIC codes. This algorithm would be used in a large scale PIC production code such as the UCLA 3D gyrokinetic code

  16. Light absorption and scattering mechanisms in laser fusion plasmas

    International Nuclear Information System (INIS)

    Barnes, C.; Estabrook, K.G.; Kruer, W.L.; Langdon, A.B.; Lasinski, B.F.; Max, C.E.; Randall, C.; Thomson, J.J.

    1977-01-01

    The picture of laser light absorption and scattering which is emerging from theory and computer simulation studies of laser-plasma interactions is described. On the subject of absorption, we discuss theoretical and experimental evidence that resonance absorption in a steepened density profile is a dominant absorption mechanism. Recent work also indicates the presence of critical surface ripples, which we study using two and three dimensional computer simulations. Predictions of hot electron spectra due to resonance absorption are described, as are effects of plasma outflow. We then discuss two regimes where stimulated scattering may occur. Brillouin scattering is expected in the underdense target blow-off, for long laser pulses, and is limited by ion heating. Raman scattering in the background gas of a reactor target chamber is predicted to be at most a 10 percent effect for 1 μm lasers

  17. Impeding hohlraum plasma stagnation in inertial-confinement fusion.

    Science.gov (United States)

    Li, C K; Séguin, F H; Frenje, J A; Rosenberg, M J; Rinderknecht, H G; Zylstra, A B; Petrasso, R D; Amendt, P A; Landen, O L; Mackinnon, A J; Town, R P J; Wilks, S C; Betti, R; Meyerhofer, D D; Soures, J M; Hund, J; Kilkenny, J D; Nikroo, A

    2012-01-13

    This Letter reports the first time-gated proton radiography of the spatial structure and temporal evolution of how the fill gas compresses the wall blowoff, inhibits plasma jet formation, and impedes plasma stagnation in the hohlraum interior. The potential roles of spontaneously generated electric and magnetic fields in the hohlraum dynamics and capsule implosion are discussed. It is shown that interpenetration of the two materials could result from the classical Rayleigh-Taylor instability occurring as the lighter, decelerating ionized fill gas pushes against the heavier, expanding gold wall blowoff. This experiment showed new observations of the effects of the fill gas on x-ray driven implosions, and an improved understanding of these results could impact the ongoing ignition experiments at the National Ignition Facility.

  18. MHD equilibrium of toroidal fusion plasma with stationary flows

    International Nuclear Information System (INIS)

    Galkowski, A.

    1994-01-01

    Non-linear ideal MHD equilibria in axisymmetric system with flows are examined, both in 1st and 2nd ellipticity regions. Evidence of the bifurcation of solutions is provided and numerical solutions of several problems in a tokamak geometry are given, exhibiting bifurcation phenomena. Relaxation of plasma in the presence of zero-order flows is studied in a realistic toroidal geometry. The field aligned flow allows equilibria with finite pressure gradient but with homogeneous temperature distribution. Numerical calculations have been performed for the 1st and 2nd ellipticity regimes of the extended Grad-Shafranov-Schlueter equation. Numerical technique, alternative to the well-known Grad's ADM methods has been proposed to deal with slow adiabatic evolution of toroidal plasma with flows. The equilibrium problem with prescribed adiabatic constraints may be solved by simultaneous calculations of flux surface geometry and original profile functions. (author). 178 refs, 37 figs, 5 tabs

  19. Effect of impurities on kinetic transport processes in fusion plasmas

    Energy Technology Data Exchange (ETDEWEB)

    Braun, Stefanie

    2010-12-10

    Within the framework of this thesis, different problems arising in connection with impurities have been investigated. Collisional damping of zonal flows in tokamaks: Since the Coulomb collision frequency increases with increasing ion charge, heavy, highly charged impurities play an important role in this process. The effect of such impurities on the linear response of the plasma to an external potential perturbation, as caused by zonal flows, is calculated with analytical methods. In comparison with a pure plasma, the damping of the flows occurs, as expected, considerably faster; for experimentally relevant parameters, the enhancement exceeds the effective charge Z{sub eff} of the plasma. Impurity transport driven by microturbulence in tokamaks: With regard to impurities, it is especially important whether the resulting flows are directed inwards or outwards, since they are deleterious for core energy confinement on the one hand, but on the other hand help protecting plasma-facing components from too high energy fluxes in the edge region. A semi-analytical model is presented describing the resulting impurity fluxes and the stability boundary of the underlying mode. The main goal is to bridge the gap between, on the one hand, costly numerical simulations, which are applicable to a broad range of problems but yield scarcely traceable results, and, on the other hand, analytical theory, which might ease the interpretation of the results but is so far rather rudimentary. The model is based on analytical formulae whenever possible but resorts to a numerical treatment when the approximations necessary for an analytical solution would lead to a substantial distortion of the results. Both the direction of the impurity flux and the stability boundary are found to depend sensitively on the plasma parameters such as the impurity density and the temperature gradient. Pfirsch-Schlueter transport in stellarators: Due to geometry effects, collisional transport plays a much more

  20. Experimental setup for producing tungsten coated graphite tiles using plasma enhanced chemical vapor deposition technique for fusion plasma applications

    International Nuclear Information System (INIS)

    Chauhan, Sachin Singh; Sharma, Uttam; Choudhary, K.K.; Sanyasi, A.K.; Ghosh, J.; Sharma, Jayshree

    2013-01-01

    Plasma wall interaction (PWI) in fusion grade machines puts stringent demands on the choice of materials in terms of high heat load handling capabilities and low sputtering yields. Choice of suitable material still remains a challenge and open topic of research for the PWI community. Carbon fibre composites (CFC), Beryllium (Be), and Tungsten (W) are now being considered as first runners for the first wall components of future fusion machines. Tungsten is considered to be one of the suitable materials for the job because of its superior properties than carbon like low physical sputtering yield and high sputter energy threshold, high melting point, fairly high re-crystallization temperature, low fuel retention capabilities, low chemical sputtering with hydrogen and its isotopes and most importantly the reparability with various plasma techniques both ex-situ and in-situ. Plasma assisted chemical vapour deposition is considered among various techniques as the most preferable technique for fabricating tungsten coated graphite tiles to be used as tokamak first wall and target components. These coated tiles are more favourable compared to pure tungsten due to their light weight and easier machining. A system has been designed, fabricated and installed at SVITS, Indore for producing tungsten coated graphite tiles using Plasma Enhanced Chemical Vapor Deposition (PE-CVD) technique for Fusion plasma applications. The system contains a vacuum chamber, a turbo-molecular pump, two electrodes, vacuum gauges, mass analyzer, mass flow controllers and a RF power supply for producing the plasma using hydrogen gas. The graphite tiles will be put on one of the electrodes and WF6 gas will be inserted in a controlled manner in the hydrogen plasma to achieve the tungsten-coating with WF6 dissociation. The system is integrated at SVITS, Indore and a vacuum of the order of 3*10 -6 is achieved and glow discharge plasma has been created to test all the sub-systems. The system design with

  1. Multichannel far-infrared phase imaging for fusion plasmas

    International Nuclear Information System (INIS)

    Young, P.E.; Neikirk, D.P.; Tong, P.P.; Rutledge, D.B.; Luhmann, N.C. Jr.

    1985-01-01

    A 20-channel far-infrared imaging interferometer system has been used to obtain single-shot density profiles in the UCLA Microtor tokamak. This system differs from conventional multichannel interferometers in that the phase distribution produced by the plasma is imaged onto a single, monolithic, integrated microbolometer linear detector array and provides significantly more channels than previous far-infrared interferometers. The system has been demonstrated to provide diffraction-limited phase images of dielectric targets

  2. Burn stability of tokamak fusion plasmas with synergetic current drive

    International Nuclear Information System (INIS)

    Anderson, D.; Lisak, M.; Kolesnichenko, Ya.

    1991-01-01

    The stability of thermonuclear burn in Tokamak-reactors with non-inductive current generated with the simultaneous application of various methods is investigated. Particular emphasis is given to the ITER synergetic current drive scenario involving LH waves, neoclassical effects and NB injection. For ITER-like confinement laws, it is shown that this scenario may be unstable on the plasma skin time scale. Figs

  3. 2003 activity report of the development and research line in controlled thermonuclear fusion of the Plasma Associated Laboratory

    International Nuclear Information System (INIS)

    Ludwig, Gerson Otto

    2004-01-01

    This document represents the 2003 activity report of the development and research line in controlled thermonuclear fusion of the Plasma Associated Laboratory - Brazil, approaching the areas of toroidal systems for magnetic confinement, plasma heating, current generation and high temperature plasma diagnostic

  4. Including plasma and fusion topics in the science education in school

    International Nuclear Information System (INIS)

    Kado, Shinichiro

    2015-01-01

    Yutori education (more relaxed education policy) started with the revision of the Courses of Study to introduce 'five-day week system' in 1989, continued with the reduction of the content of school lessons by 30% in 1998, and ended with the introduction of the New Courses of Study in 2011. Focusing on science education, especially in the topics of plasma and nuclear fusion, the modality of the education system in Japan is discussed considering the transition of academic performance based on the Program for International Student Assessment (PISA) in comparison with the examples in other countries. Particularly, the issues with high school textbooks are pointed out from the assessment of current textbooks, and the significance and the need for including the topic of 'plasma' in them are stated. Lastly, in order to make the general public acknowledged with plasma and nuclear fusion, it is suggested to include them also in junior high school textbooks, by briefly mentioning the terms related to plasma, solar wind, aurora phenomenon, and nuclear fusion energy. (S.K.)

  5. Role of Radio Frequency and Microwaves in Magnetic Fusion Plasma Research

    Directory of Open Access Journals (Sweden)

    Hyeon K. Park

    2017-10-01

    Full Text Available The role of electromagnetic (EM waves in magnetic fusion plasma—ranging from radio frequency (RF to microwaves—has been extremely important, and understanding of EM wave propagation and related technology in this field has significantly advanced magnetic fusion plasma research. Auxiliary heating and current drive systems, aided by various forms of high-power RF and microwave sources, have contributed to achieving the required steady-state operation of plasmas with high temperatures (i.e., up to approximately 10 keV; 1 eV = 10000 K that are suitable for future fusion reactors. Here, various resonance values and cut-off characteristics of wave propagation in plasmas with a nonuniform magnetic field are used to optimize the efficiency of heating and current drive systems. In diagnostic applications, passive emissions and active sources in this frequency range are used to measure plasma parameters and dynamics; in particular, measurements of electron cyclotron emissions (ECEs provide profile information regarding electron temperature. Recent developments in state-of-the-art 2D microwave imaging systems that measure fluctuations in electron temperature and density are largely based on ECE. The scattering process, phase delays, reflection/diffraction, and the polarization of actively launched EM waves provide us with the physics of magnetohydrodynamic instabilities and transport physics.

  6. Plasma-material Interactions in Current Tokamaks and their Implications for Next-step Fusion Reactors

    International Nuclear Information System (INIS)

    Federici, G.; Skinner, C.H.; Brooks, J.N.; Coad, J.P.; Grisolia, C.

    2001-01-01

    The major increase in discharge duration and plasma energy in a next-step DT (deuterium-tritium) fusion reactor will give rise to important plasma-material effects that will critically influence its operation, safety, and performance. Erosion will increase to a scale of several centimeters from being barely measurable at a micron scale in today's tokamaks. Tritium co-deposited with carbon will strongly affect the operation of machines with carbon plasma-facing components. Controlling plasma wall interactions is critical to achieving high performance in present-day tokamaks and this is likely to continue to be the case in the approach to practical fusion reactors. Recognition of the important consequences of these phenomena has stimulated an internationally coordinated effort in the field of plasma-surface interactions supporting the Engineering Design Activities of the International Thermonuclear Experimental Reactor (ITER) project and significant progress has been made in better under standing these issues. This paper reviews the underlying physical processes and the existing experimental database of plasma-material interactions both in tokamaks and laboratory simulation facilities for conditions of direct relevance to next-step fusion reactors. Two main topical groups of interactions are considered: (i) erosion/redeposition from plasma sputtering and disruptions, including dust and flake generation, (ii) tritium retention and removal. The use of modeling tools to interpret the experimental results and make projections for conditions expected in future devices is explained. Outstanding technical issues and specific recommendations on potential R and D (Research and Development) avenues for their resolution are presented

  7. Plasma-material Interactions in Current Tokamaks and their Implications for Next-step Fusion Reactors

    Energy Technology Data Exchange (ETDEWEB)

    Federici, G.; Skinner, C.H.; Brooks, J.N.; Coad, J.P.; Grisolia, C. [and others

    2001-01-10

    The major increase in discharge duration and plasma energy in a next-step DT [deuterium-tritium] fusion reactor will give rise to important plasma-material effects that will critically influence its operation, safety, and performance. Erosion will increase to a scale of several centimeters from being barely measurable at a micron scale in today's tokamaks. Tritium co-deposited with carbon will strongly affect the operation of machines with carbon plasma-facing components. Controlling plasma wall interactions is critical to achieving high performance in present-day tokamaks and this is likely to continue to be the case in the approach to practical fusion reactors. Recognition of the important consequences of these phenomena has stimulated an internationally coordinated effort in the field of plasma-surface interactions supporting the Engineering Design Activities of the International Thermonuclear Experimental Reactor (ITER) project and significant progress has been made in better under standing these issues. This paper reviews the underlying physical processes and the existing experimental database of plasma-material interactions both in tokamaks and laboratory simulation facilities for conditions of direct relevance to next-step fusion reactors. Two main topical groups of interactions are considered: (i) erosion/redeposition from plasma sputtering and disruptions, including dust and flake generation, (ii) tritium retention and removal. The use of modeling tools to interpret the experimental results and make projections for conditions expected in future devices is explained. Outstanding technical issues and specific recommendations on potential R and D [Research and Development] avenues for their resolution are presented.

  8. Interaction between sheared flows and turbulent transport in magnetized fusion-grade plasmas; Interaction entre ecoulements cisailles et transport turbulent dans les plasmas de fusion magnetique

    Energy Technology Data Exchange (ETDEWEB)

    Leconte, M.

    2008-11-15

    The H confinement regime is set when the heating power reaches a threshold value P{sub c} and is linked to the formation of a transport barrier in the edge region of the plasma. Such a barrier is characterized by a high pressure gradient and is submitted to ELM (edge localized mode) instabilities. ELM instabilities trigger violent quasi-periodical ejections of matter and heat that induce quasi-periodical relaxations of the transport barrier called relaxation oscillations. In this work we studied the interaction between sheared flows and turbulence in fusion plasmas. In particular, we studied the complex dynamics of a transport barrier and we show through a simulation that resonant magnetic perturbations could control relaxation oscillations without a significant loss of confinement

  9. Fusion plasma theory. Task I. Magnetic confinement fusion plasma theory. Annual progress report, January 1, 1982-December 31, 1982

    International Nuclear Information System (INIS)

    Callen, J.D.

    1982-08-01

    The research on this contract over the past year has concentrated on some key tandem mirror confinement and heating issues (barrier trapping current, rf heating, low mode number stability) and on developing a comprehensive neoclassical transport theory for nonaxisymmetric toroidal plasmas (e.g., stellarators). Progress in these and some other miscellaneous areas are summarized briefly in this progress report

  10. Plasma-Jet-Driven Magneto-Inertial Fusion (PJMIF): Physics and Design for a Plasma Liner Formation Experiment

    Science.gov (United States)

    Hsu, Scott; Cassibry, Jason; Witherspoon, F. Douglas

    2014-10-01

    Spherically imploding plasma liners are a potential standoff compression driver for magneto-inertial fusion, which is a hybrid of and operates in an intermediate density between those of magnetic and inertial fusion. We propose to use an array of merging supersonic plasma jets to form a spherically imploding plasma liner. The jets are to be formed by pulsed coaxial guns with contoured electrodes that are placed sufficiently far from the location of target compression such that no hardware is repetitively destroyed. As such, the repetition rate can be higher (e.g., 1 Hz) and ultimately the power-plant economics can be more attractive than most other MIF approaches. During the R&D phase, a high experimental shot rate at reasonably low cost (e.g., gun plasma-liner-formation experiment, which will provide experimental data on: (i) scaling of peak liner ram pressure versus initial jet parameters, (ii) liner non-uniformity characterization and control, and (iii) control of liner profiles for eventual gain optimization.

  11. Fusion plasma theory: Task 3, Auxiliary heating in tokamaks

    International Nuclear Information System (INIS)

    Scharer, J.E.

    1989-07-01

    The research that we have accomplished during the past year (1988--1989) includes the topics of ICRF fast wave waveguide coupling to H-mode profiles simulating CIT and full wave ICRF field solutions and a power conservation relation based on fundamental principles with JET and CIT heating applications. We have also published work on Fokker-Planck simulations of minority ion ICRF strong core electron sawteeth processes in JET, a publication on the effect of plasma edge density fluctuation and ponderomotive force effects on the coupling of ion Bernstein waves and a publication on the coupling of dielectric filled waveguides to plasmas in the ICRF. The analysis of ICRF H-mode coupling is crucial to the economic success of proposed ignition devices such as CIT and ITER. We have analyzed the coupling of ICRF waveguide launchers to H-mode density profiles modelled by a pedestal width and Gaussian edge variations with gradients comparable to current machines. We find that the launcher aperture spectrum, density gradients and width of the pedestal are important parameters in determining the coupling efficiency. The launcher-plasma admittance spectrum in k y -k z space is utilized to show that the H-mode launcher reflections increase when compared to the L-mode profile, but that they can be handled by launcher matching circuits and modest modifications of the H-mode profile. We plan to analyze the recent successful JET ICRF H-mode operation utilizing our formalism. We have also carried out a full wave ICRF field solution and the associated power conservation relation with expressions evaluated up to the third harmonic. We have implemented this in a computer code which utilizes invariant imbedding to solve the system of equations. 7 refs., 1 tab

  12. III Workshop on Microwave Reflectometry for Fusion Plasma Diagnostics

    International Nuclear Information System (INIS)

    Sanchez, J.; Luna, E. de la.

    1997-11-01

    Microwave reflectometry is based on the analysis of the properties (phase delay, time delay, amplitude) of a millimeter wave beam which is launched and reflected at the plasma critical layer. Operation with a fixed frequency beam can be used to analyze the electron density fluctuations in the reflecting region. If several frequencies are launched, information about the density profile can be obtained. In these proceedings, a collection of papers is presented on the issues of density fluctuation studies and profile analysis as well as a special contribution about the development of reflectometry for the ITER project. (Author) 145 refs

  13. III Workshop on Microwave Reflectometry for Fusion Plasma Diagnostics

    Energy Technology Data Exchange (ETDEWEB)

    Sanchez, J; Luna, E de la

    1997-11-01

    Microwave reflectometry is based on the analysis of the properties (phase delay, time delay, amplitude) of a millimeter wave beam which is launched and reflected at the plasma critical layer. Operation with a fixed frequency beam can be used to analyze the electron density fluctuations in the reflecting region. If several frequencies are launched, information about the density profile can be obtained. In these proceedings, a collection of papers is presented on the issues of density fluctuation studies and profile analysis as well as a special contribution about the development of reflectometry for the ITER project. (Author) 145 refs.

  14. Control of ITBs in Fusion Self-Heated Plasmas

    Science.gov (United States)

    Panta, Soma; Newman, David; Terry, Paul; Sanchez, Raul

    2015-11-01

    Simple dynamical models have been able to capture a remarkable amount of the dynamics of the transport barriers found in many devices, including the often disconnected nature of the electron thermal transport channel sometimes observed in the presence of a standard (``ion channel'') barrier. By including in this rich though simple dynamic transport model an evolution equation for electron fluctuations we have previously investigated the interaction between the formation of the standard ion channel barrier and the somewhat less common electron channel barrier. The electron channel formation and evolution is even more sensitive to the alignment of the various gradients making up the sheared radial electric field then the ion barrier is. Because of this sensitivity and coupling of the barrier dynamics, the dynamic evolution of the fusion self-heating profile can have a significant impact on the barrier location and dynamics. To investigate this, self-heating has been added this model and the impact of the self-heating on the formation and controllability of the various barriers is explored. It has been found that the evolution of the heating profiles can suppress or collapse the electron channel barrier. NBI and RF schemes will be investigated for profile/barrier control.

  15. Steady State Turbulent Transport in Magnetic Fusion Plasmas

    International Nuclear Information System (INIS)

    Lee, W.W.; Ethier, S.; Kolesnikov, R.; Wang, W.X.; Tang, W.M.

    2007-01-01

    For more than a decade, the study of microturbulence, driven by ion temperature gradient (ITG) drift instabilities in tokamak devices, has been an active area of research in magnetic fusion science for both experimentalists and theorists alike. One of the important impetus for this avenue of research was the discovery of the radial streamers associated the ITG modes in the early nineties using a Particle-In-Cell (PIC) code. Since then, ITG simulations based on the codes with increasing realism have become possible with the dramatic increase in computing power. The notable examples were the demonstration of the importance of nonlinearly generated zonal flows in regulating ion thermal transport and the transition from Bohm to GyroBoham scaling with increased device size. In this paper, we will describe another interesting nonlinear physical process associated with the parallel acceleration of the ions, that is found to play an important role for the steady state turbulent transport. Its discovery is again through the use of the modern massively parallel supercomputers

  16. Studies of neutron measurement methods for fusion plasma diagnostics

    International Nuclear Information System (INIS)

    Beimer, K.H.

    1986-03-01

    This thesis comprises several studies mainly devoted to neutron measurement systems for plasma diagnostics at JET (Joint European Torus). An in situ calibration of the U-235 fission chamber detectors located at JET is presented. These detectors are used for measuring the neutron yield from the thermonuclear reactions in the plasma. The energy spectrum of the neutrons from the reactions D(d,n) 3 He has been studied by means of a 3 He spectrometer. Especially, it was found that by measuring the width of the full energy peak in the response spectrum of the 3 He-spectrometer, the deuterium distribution in the deuterium targets used can be estimated. In order to measure different neutron energies it is necessary to obtain a detailed knowledge of the response of the spectrometer. Therefore, the response function to monoenergetic neutrons in the energy range 130-3030 keV was experimentally determined. Some work has been related to a design study of a 14 MeV spectrometer for neutron diagnostics. It is a combined proton-recoil and time-of-flight spectrometer for high resolution measurements. The main parts of it are the collimator, the scattering foil, and the detectors for the recoil protons and the scattered neutrons. The influence of proton straggling in the foil on the resolution and efficiency of the spectrometer has been studied. Furthermore, a three dimensional Monte Carlo code has been written and used for the design of the collimator. (author)

  17. A unified model of density limit in fusion plasmas

    Science.gov (United States)

    Zanca, P.; Sattin, F.; Escande, D. F.; Pucella, G.; Tudisco, O.

    2017-05-01

    In this work we identify by analytical and numerical means the conditions for the existence of a magnetic and thermal equilibrium of a cylindrical plasma, in the presence of Ohmic and/or additional power sources, heat conduction and radiation losses by light impurities. The boundary defining the solutions’ space having realistic temperature profile with small edge value takes mathematically the form of a density limit (DL). Compared to previous similar analyses the present work benefits from dealing with a more accurate set of equations. This refinement is elementary, but decisive, since it discloses a tenuous dependence of the DL on the thermal transport for configurations with an applied electric field. Thanks to this property, the DL scaling law is recovered almost identical for two largely different devices such as the ohmic tokamak and the reversed field pinch. In particular, they have in common a Greenwald scaling, linearly depending on the plasma current, quantitatively consistent with experimental results. In the tokamak case the DL dependence on any additional heating approximately follows a 0.5 power law, which is compatible with L-mode experiments. For a purely externally heated configuration, taken as a cylindrical approximation of the stellarator, the DL dependence on transport is found stronger. By adopting suitable transport models, DL takes on a Sudo-like form, in fair agreement with LHD experiments. Overall, the model provides a good zeroth-order quantitative description of the DL, applicable to widely different configurations.

  18. Workshop on Molecule Assisted Recombination and Other Processes in Fusion Divertor Plasmas, September 8-9, 2000

    International Nuclear Information System (INIS)

    Janev, R.K.; Schultz, D.R.

    2000-01-01

    A brief proceedings of the two-day Workshop on Molecule Assisted Recombination and Other Processes in Fusion Divertor Plasmas, organized by the ORNL Controlled Fusion Atomic Data Center on September 8-9, 2000, is presented. The conclusions and recommendations of the workshop regarding the topics discussed and the collaboration of the U.S. fusion research and atomic physics communities are also summarized

  19. Noise temperature improvement for magnetic fusion plasma millimeter wave imaging systems.

    Science.gov (United States)

    Lai, J; Domier, C W; Luhmann, N C

    2014-03-01

    Significant progress has been made in the imaging and visualization of magnetohydrodynamic and microturbulence phenomena in magnetic fusion plasmas [B. Tobias et al., Plasma Fusion Res. 6, 2106042 (2011)]. Of particular importance have been microwave electron cyclotron emission imaging and microwave imaging reflectometry systems for imaging T(e) and n(e) fluctuations. These instruments have employed heterodyne receiver arrays with Schottky diode mixer elements directly connected to individual antennas. Consequently, the noise temperature has been strongly determined by the conversion loss with typical noise temperatures of ~60,000 K. However, this can be significantly improved by making use of recent advances in Monolithic Microwave Integrated Circuit chip low noise amplifiers to insert a pre-amplifier in front of the Schottky diode mixer element. In a proof-of-principle design at V-Band (50-75 GHz), significant improvement of noise temperature from the current 60,000 K to measured 4000 K has been obtained.

  20. Noise temperature improvement for magnetic fusion plasma millimeter wave imaging systems

    International Nuclear Information System (INIS)

    Lai, J.; Domier, C. W.; Luhmann, N. C.

    2014-01-01

    Significant progress has been made in the imaging and visualization of magnetohydrodynamic and microturbulence phenomena in magnetic fusion plasmas [B. Tobias et al., Plasma Fusion Res. 6, 2106042 (2011)]. Of particular importance have been microwave electron cyclotron emission imaging and microwave imaging reflectometry systems for imaging T e and n e fluctuations. These instruments have employed heterodyne receiver arrays with Schottky diode mixer elements directly connected to individual antennas. Consequently, the noise temperature has been strongly determined by the conversion loss with typical noise temperatures of ∼60 000 K. However, this can be significantly improved by making use of recent advances in Monolithic Microwave Integrated Circuit chip low noise amplifiers to insert a pre-amplifier in front of the Schottky diode mixer element. In a proof-of-principle design at V-Band (50–75 GHz), significant improvement of noise temperature from the current 60 000 K to measured 4000 K has been obtained

  1. Effects of large-angle Coulomb collisions on inertial confinement fusion plasmas.

    Science.gov (United States)

    Turrell, A E; Sherlock, M; Rose, S J

    2014-06-20

    Large-angle Coulomb collisions affect the rates of energy and momentum exchange in a plasma, and it is expected that their effects will be important in many plasmas of current research interest, including in inertial confinement fusion. Their inclusion is a long-standing problem, and the first fully self-consistent method for calculating their effects is presented. This method is applied to "burn" in the hot fuel in inertial confinement fusion capsules and finds that the yield increases due to an increase in the rate of temperature equilibration between electrons and ions which is not predicted by small-angle collision theories. The equilibration rate increases are 50%-100% for number densities of 10(30)  m(-3) and temperatures around 1 keV.

  2. Beam plasma 14 MeV neutron source for fusion materials development

    International Nuclear Information System (INIS)

    Ravenscroft, D.; Bulmer, D.; Coensgen, F.; Doggett, J.; Molvik, A.; Souza, P.; Summers, L.; Williamson, V.

    1991-09-01

    The conceptual engineering design and expected performance for a 14 MeV DT neutron source is detailed. The source would provide an intense neutron flux for accelerated testing of fusion reactor materials. The 150-keV neutral beams inject energetic deuterium atoms, that ionize, are trapped, then react with a warm (200 eV), dense tritium target plasma. This produces a neutron source strength of 3.6 x 10 17 n/sec for a neutron power density at the plasma edge of 5--10 MW/m 2 . This is several times the ∼2 MW/m 2 anticipated at the first wall of fusion reactors. This high flux provides accelerated end-of-life tests of 1- to 2-year duration, thus making materials development possible. The modular design of the source and the facilities are described

  3. Developing a plasma focus research training system for the fusion energy age

    International Nuclear Information System (INIS)

    Lee, S.

    2014-01-01

    The 3 kJ UNU/ICTP Plasma Focus Facility is the most significant device associated with the AAAPT (Asian African Association for Plasma Training). In original and modified/upgraded form it has trained generations of plasma focus (PF) researchers internationally, producing many PhD theses and peer-reviewed papers. The Lee Model code was developed for the design of this PF. This code has evolved to cover all PF machines for design, interpretation and optimization, for derivation of radiation scaling laws; and to provide insights into yield scaling limitations, radiative collapse, speed-enhanced and current-stepped PF variants. As example of fresh perspectives derivable from this code, this paper presents new results on energy transfers of the axial and radial phases of generalized PF devices. As the world moves inexorably towards the Fusion Energy Age it becomes ever more important to train plasma fusion researchers. A recent workshop in Nepal shows that demand for such training continues. Even commercial project development consultants are showing interest. We propose that the AAAPT-proven research package be upgraded, by modernizing the small PF for extreme modes of operation, switchable from the typical strong-focus mode to a slow-mode which barely pinches, thus producing a larger, more uniform plasma stream with superior deposition properties. Such a small device would be cost-effective and easily duplicated, and have the versatility of a range of experiments from intense multi-radiation generation and target damage studies to superior advanced-materials deposition. The complementary code is used to reference experiments up to the largest existing machine. This is ideal for studying machine limitations and scaling laws and to suggest new experiments. Such a modernized versatile PF machine complemented by the universally versatile code would extend the utility of the PF experience; so that AAAPT continues to provide leadership in pulsed plasma research training in

  4. A DOE/Fusion Energy Sciences Research/Education Program at PVAMU Study of Rotamak Plasmas

    Energy Technology Data Exchange (ETDEWEB)

    Huang, Tian-Sen [Prairie View A& M Univ., Prairie View, TX (United States); Saganti, Premkumar [Prairie View A& M Univ., Prairie View, TX (United States)

    2017-02-17

    During recent years (2004-2015), with DOE support, the PVAMU plasma research group accomplished new instrumentation development, conducted several new plasma experiments, and is currently poised to advance with standing-wave microwave plasma propulsion research. On the instrumentation development, the research group completed: (i) building a new plasma chamber with metal CF flanges, (ii) setting up of a 6kW/2450MHz microwave input system as an additional plasma heating source at our rotamak plasma facility, (iii) installation of one programmatic Kepco ATE 6-100DMG fast DC current supply system used in rotamak plasma shape control experiment, built a new microwave, standing-wave experiment chamber and (iv) established a new plasma lab with field reversal configuration capability utilizing 1MHz/200kW RF (radio frequency) wave generator. Some of the new experiments conducted in this period also include: (i) assessment of improved magnetic reconnection at field-reversed configuration (FRC) plasma, (ii) introduction of microwave heating experiments, and (iii) suppression of n = 1 tilt instability by one coil with a smaller current added inside the rotamak’s central pipe. These experiments led to publications in Physical Review Letters, Reviews of Scientific Instruments, Division of Plasma Physics (DPP) of American Physical Society (APS) Reports, Physics of Plasmas Controlled Fusion, and Physics of Plasmas (between 2004 and 2015). With these new improvements and advancements, we also initiated and accomplished design and fabrication of a plasma propulsion system. Currently, we are assembling a plasma propulsion experimental system that includes a 5kW helicon plasma source, a 25 cm diameter plasma heating chamber with 1MHz/200kW RF power rotating magnetic field, and a 60 cm diameter plasma exhaust chamber, and expect to achieve a plasma mass flow of 0.1g/s with 60km/s ejection. We anticipate several propulsion applications in near future as we advance our capabilities

  5. Using plasma waves to create in tokamaks the necessary quasi-stationary conditions for controlled fusion

    International Nuclear Information System (INIS)

    Moreau, D.

    1993-04-01

    It is studied, on the one hand, how using hybrid waves with frequency near from lower hybrid frequency in fusion plasma. Works about coupling waves in plasma (chap.I), their propagation and response of the plasma to the absorption of the waves (chap.II). This method is the most effective until today. Because of limits, it has been investigated, on the other hand, fast magnetosonic wave to control current density in the centre of the discharge in a reactor or a very hot plasma. Theoretical study (chap.III) and experimental results (chap.IV) are presented. Experiments are in progress or planned in following tokamaks: D3-D (USA), JET (Europe), TORE SUPRA (France), JT-60 (Japan). figs. refs. tabs

  6. Self-limitation of impurity production by radiation cooling at the edge of a fusion plasma

    International Nuclear Information System (INIS)

    Neuhauser, J.; Lackner, K.; Wunderlich, R.

    1982-04-01

    The influence of radiation cooling at the edge of a fusion plasma on the plasma-wall interaction is numerically studied for parameters typical of the ZEPHYR ignition experiment. Various transport and impurity influx models and different external heating methods are studied using the 1D tokamak transport code BALDUR developed at Princeton. The results demonstrate the self-consistent formation of a radiating boundary layer (photosphere) for a wide range of parameters, limiting the impurity concentration in the plasma to a tolerable value. While the plasma behaviour is rather insensitive to model assumptions, the sputtering rate and the corresponding wall erosion depend on various parameters. Methods for external control of the photosphere and - more important - of the wall erosion are also discussed. (orig.)

  7. Fusion reaction yield in focused discharges with variable energy and plasma fine structure

    International Nuclear Information System (INIS)

    Bortolotti, A.; Brzosko, J.S.; Chiara, P. De; Kilic, H.; Mezzetti, F.; Nardi, V.; Powell, C.; Wang, J.

    1992-01-01

    The same linear correlation between the distribution parameters (ΔT and Max ΔV) of the radial current density J between electrodes and the fusion reaction yield per pulse, Y, in the plasma focus (PF) pinch was quantitatively determined from different PF machines. Contact prints of current-sheath fragments (CSF) ejected from the pinch are obtained from 2.5-MeV-D + ions. CSF's show the same submillimetric fine structure of the pinch. (author) 3 refs., 2 tabs

  8. EU-US transport task force workshop on transport in fusion plasmas: transport near operational limits

    International Nuclear Information System (INIS)

    Connor, J W; Garbet, X; Giannone, L; Greenwald, M; Hidalgo, C; Loarte, A; Mantica, P

    2003-01-01

    This conference report summarizes the contributions to, and discussions at, the 9th EU-US transport task force workshop on 'transport in fusion plasmas: transport near operational limits', held in Cordoba, Spain, during 9-12 September 2002. The workshop was organized under three main headings: edge localized mode physics and confinement, profile dynamics and confinement and confinement near operational limits: density and beta limits; this report follows the same structure

  9. Characterization of the Plasma Edge for Technique of Atomic Helium Beam in the CIEMAT Fusion Device

    International Nuclear Information System (INIS)

    Hidalgo, A.

    2003-01-01

    In this report, the measurement of Electron Temperature and Density in the Boundary Plasma of TJ-II with a Supersonic Helium Beam Diagnostic and work devoted to the upgrading of this technique are described. Also, simulations of Laser Induced Fluorescence (LIF) studies of level populations of electronically excited He atoms are shown. This last technique is now being installed in the CIEMAT fusion device. (Author )

  10. Prospects for x-ray polarimetry measurements of magnetic fields in magnetized liner inertial fusion plasmas.

    Science.gov (United States)

    Lynn, Alan G; Gilmore, Mark

    2014-11-01

    Magnetized Liner Inertial Fusion (MagLIF) experiments, where a metal liner is imploded to compress a magnetized seed plasma may generate peak magnetic fields ∼10(4) T (100 Megagauss) over small volumes (∼10(-10)m(3)) at high plasma densities (∼10(28)m(-3)) on 100 ns time scales. Such conditions are extremely challenging to diagnose. We discuss the possibility of, and issues involved in, using polarimetry techniques at x-ray wavelengths to measure magnetic fields under these extreme conditions.

  11. Preliminary study on power balance in the plasma of an experimental fusion reactor

    International Nuclear Information System (INIS)

    Tone, Tatsuzo; Yamato, Harumi

    1976-03-01

    The preliminary study on power balance in the plasma is described in the first-stage design of an experimental fusion reactor. The purpose is to show the ranges of plasma parameters for the design output of about 100 MW with an injection power less than 50 MW. The impurity is permitted to the extent of Zsub(eff) -- 5 to meet the design requirement. Influences of the uncertainty in scaling law on the power output and injection power are discussed, and also possibility of the self-ignition. (auth.)

  12. On the link between ExB sheared flows and rational surfaces in fusion plasmas

    International Nuclear Information System (INIS)

    Hidalgo, C.; Erents, K.; Matthews, G.

    2000-11-01

    Experimental evidence of flattening in plasma profiles has been observed in the edge region of the JET tokamak. This observation has been interpreted in terms of the influence of rational surfaces on plasma profiles. In the framework of this interpretation, significant ExB sheared flows linked to rational surfaces have been identified. These ExB sheared flows are close to the critical value to trigger the transition to improved confinement regimes. These results can explain the link between the magnetic topology and the generation of transport barriers reported in fusion devices. (author)

  13. Some considerations on a plasma in the JAERI experimental fusion reactor

    International Nuclear Information System (INIS)

    Tone, T.; Yamato, H.; Maki, K.

    1976-01-01

    The preliminary analysis of the plasma characteristics for the JAERI tokamak experimental fusion reactor is reported. In order to make the reactor compact, the self-sustaining condition has been removed. Stationary heating by 200 keV neutral deuteron beam to maintain the power balance is applied expecting the power amplification by the TCT effect. The main parameters determined are power output of 100 MW, toroidal field on axis of 6 T, aspect ratio of 4.5 and major radius of 6.75 m. The results of the plasma power balance, fueling by means of the gas blanket scheme, power stabilization with feedback and the start-up are presented

  14. Interaction of heavy ions beams with hot and dense plasmas. Application to inertial fusion

    International Nuclear Information System (INIS)

    Maynard, Gilles

    1987-01-01

    The subject of this work is the variation with time, on one of the energy and charge state of an heavy ion beam which through a plasma, and on another side, of a target used in ion inertial confinement fusion. We take in account projectile excitation, and higher order corrections to the Born stopping power formula are calculated. Comparison with experimental results in gas and solid are good. In hot plasma case, non-equilibrium charge states are described. We present an hydrodynamic simulation code of one dimension and three temperatures. We show that the shortening of the heavy ions beams with temperature reinforces the radiative transfer importance. (author) [fr

  15. Gyrokinetic theory for particle and energy transport in fusion plasmas

    Science.gov (United States)

    Falessi, Matteo Valerio; Zonca, Fulvio

    2018-03-01

    A set of equations is derived describing the macroscopic transport of particles and energy in a thermonuclear plasma on the energy confinement time. The equations thus derived allow studying collisional and turbulent transport self-consistently, retaining the effect of magnetic field geometry without postulating any scale separation between the reference state and fluctuations. Previously, assuming scale separation, transport equations have been derived from kinetic equations by means of multiple-scale perturbation analysis and spatio-temporal averaging. In this work, the evolution equations for the moments of the distribution function are obtained following the standard approach; meanwhile, gyrokinetic theory has been used to explicitly express the fluctuation induced fluxes. In this way, equations for the transport of particles and energy up to the transport time scale can be derived using standard first order gyrokinetics.

  16. Interactions between plasma and wall materials in fusion reactors

    International Nuclear Information System (INIS)

    Marot, L.; Moser, L.

    2016-11-01

    First mirrors of optical diagnostics in ITER were exposed in Magnum-PSI linear plasma device and JET-ILW tokamak. For JET-ILW the mirrors with a rhodium (Rh) or a molybdenum (Mo) coating exhibited a decrease of the reflectivity according the location in the torus and especially the amount of beryllium (Be) deposited on them. No delamination of the coated reflective film was observed. Under very harsh erosion conditions in Magnum-PSI, Rh thick coated mock ups, cooled or not, for a high flux exposure the films underwent delamination. Mo coating on water cooled mock up mirrors exhibited a high diffuse reflectivity after H 2 /Ar plasma exposure inducing an important decrease of the specular reflectivity and show important oxidation of the surface. Cleaning of mirrors was extensively studied during this period, with magnetic field in collaboration with the SPC Lausanne, or in term of repetitive cleaning till 34 cycles. Polycrystalline molybdenum mirror shows a high diffuse reflectivity after cleaning cycle and clearly demonstrate that they are not suitable for this purpose. Coated Rh or Mo mirrors like single crystal maintained good reflectivity. Test under magnetic field revealed the non-uniform erosion of the mirrors according the orientation between the field and the mirror. All these tests bring to a suitable schematic of the implementation of this technique in ITER and were deeply explained. The cleaning of the Be contaminated mirrors will be carried out using new parameters in December 2016. Investigations on formation of tungsten fuzz were carried out either in Basel using a new setup or in Pilot-PSI. These thickness measurements showed the fuzz growth is in square root dependence to time or fluence. From the results in Pilot-PSI, it has been shown that time was a critical parameter for the development of He-induced morphology changes and one needs to keep that factor in mind. (authors)

  17. Fusion in the Era of Burning Plasma Studies: Workforce Planning for 2004 to 2014. Final report to FESA C

    Energy Technology Data Exchange (ETDEWEB)

    none,

    2004-03-29

    This report has been prepared in response to Dr. R. Orbach’s request of the Fusion Energy Sciences Advisory Committee (FESAC) to “address the issue of workforce development in the U.S. fusion program.” The report addresses three key questions: what is the current status of the fusion science, technology, and engineering workforce; what is the workforce that will be needed and when it will be needed to ensure that the U.S. is an effective partner in ITER and to enable the U.S. to successfully carry out the fusion program; and, what can be done to ensure a qualified, diversified, and sufficiently large workforce and a pipeline to maintain that workforce? In addressing the charge, the Panel considers a workforce that allows for a vigorous national program of fusion energy research that includes participation in magnetic fusion (ITER) and inertial fusion (NIF) burning plasma experiments.

  18. Hybrid modeling of plasma and applications to fusion and space physics

    International Nuclear Information System (INIS)

    Kazeminejad, F.

    1989-01-01

    Obtaining reasonable solutions to the nonlinear equations is crucial to the understanding of the behavior of plasmas. With the advent of high speed computers, computer modeling of plasmas has moved into the front row of the tools used in research of their nonlinear plasma dynamics. There are roughly speaking two types of plasma models, particle models and fluid models. Particle models try to emulate nature by following the motion of a large number of charged particles in their self consistent electromagnetic fields. Fluid models on the other hand use macroscopic fluid equations to model the plasma. MHD models are typical of this type. Particle models in general require larger memory for the computer due to the massive amount of data associated with the particles' kinematical variables. Particle models are generally limited to studying small regions of plasma for relatively short time intervals. Fluid models are better fit to handle large scales and long times; i.e., quite often the complete plasma involved in an experiment. The drawback of the fluid models however is that, they miss the physical phenomenon taking place at the microscale and these phenomenon can influence the properties of fluid. Another approach is to start with fluid models and incorporate more physics. Such models are referred to as hybrid models. In this thesis, two such models are discussed. They are then applied to two problems; the first is a simulation of the artificial comet generated by the AMPTE experiment; the second is the production of enhanced noise in fusion plasmas by injected energetic ions or by fusion reaction products. In both cases the models demonstrate qualitative agreement with the experimental observations

  19. Fusion reactivity, confinement, and stability of neutral-beam heated plasmas in TFTR and other tokamaks

    International Nuclear Information System (INIS)

    Park, Hyeon, K.

    1996-05-01

    The hypothesis that the heating beam fueling profile shape connects the edge condition and improved core confinement and fusion reactivity is extensively studied on TFTR and applied to other tokamaks. The derived absolute scalings based on beam fueling profile shape for the stored energy and neutron yield can be applied to the deuterium discharges at different major radii in TFTR. These include Supershot, High poloidal beta, L-mode, and discharges with a reversed shear (RS) magnetic configuration. These scalings are also applied to deuterium-tritium discharges. The role of plasma parameters, such as plasma current, Isdo2(p), edge safety factor, qsdo5(a), and toroidal field, Bsdo2(T), in the performance and stability of the discharges is explicitly studied. Based on practical and externally controllable plasma parameters, the limitation and optimization of fusion power production of the present TFTR is investigated and a path for a discharge condition with fusion power gain, Q > 1 is suggested based on this study. Similar physics interpretation is provided for beam heated discharges on other major tokamaks

  20. Evaluation of compatibility of flowing liquid lithium curtain for blanket with core plasma in fusion reactors

    International Nuclear Information System (INIS)

    Deng Baiquan; Huang Jinhua; Peng Lilin; Yan Jiancheng

    2003-01-01

    A global model analysis of the compatibility of flowing liquid lithium curtain for blanket with core plasma has been performed. The relationships between the surface temperature of lithium curtain and mean effective plasma charges, fuel dilution and produced fusion power have been obtained. Results show that under normal circumstances, the evaporation of liquid lithium does not affect Z eff seriously, but affects fuel dilution and fusion power sensitively. The authors have investigated the relationships between the flow velocity of liquid lithium and its surface temperature rise based on the conditions of the option II of the fusion experimental breeder (FEB-E) design with reversed shear configuration and fairly high power density. The authors concluded that the effects of evaporation from liquid lithium curtain for FEB-E on plasma are negligible even if the flow velocity of liquid lithium is as low as 0.5 m·s -1 . Finally, the sputtering yield of liquid lithium saturated by hydrogen isotopes is briefly discussed

  1. Fusion Plasma Modelling Using Atomic and Molecular Data. Summary report of a Joint ICTP-IAEA Workshop

    International Nuclear Information System (INIS)

    Braams, B.J.

    2012-03-01

    The Joint ICTP-IAEA Workshop on Fusion Plasma Modelling using Atomic and Molecular Data was held from 23-27 January 2012 at Abdus Salam International Centre for Theoretical Physics in Trieste, Italy. Ten lecturers presented tutorials and reviews on topics in fusion plasma modelling and atomic, molecular and plasma-material interaction processes. There were 20 participants, generally early-career researchers in the area of A+M+PMI processes and also plasma modellers. The participants presented their work in short talks and a poster session. The proceedings of the workshop are summarized here. (author)

  2. Atomic and plasma-material interaction data for fusion. V. 7, part B. Particle induced erosion of Be, C and W in fusion plasmas. Part B: Physical sputtering and radiation-enhanced sublimation

    International Nuclear Information System (INIS)

    Eckstein, W.; Stephens, J.A.; Clark, R.E.H.; Davis, J.W.; Haasz, A.A.; Vietzke, E.; Hirooka, Y.

    2001-01-01

    The present volume of Atomic and Plasma-Material Interaction Data for Fusion is devoted to a critical review of the physical sputtering and radiation enhanced sublimation (RES) behaviour of fusion plasma-facing materials, in particular carbon, beryllium and tungsten. The present volume is intended to provide fusion reactor designers a detailed survey and parameterization of existing, critically assessed data for the chemical erosion of plasma-facing materials by particle impact. The survey and data compilation is presented for a variety of materials containing the elements C, Be and W (including dopants in carbon materials) and impacting plasma species. The dependencies of physical sputtering and RES yields on the material temperature, incident projectile energy, and incident flux are considered. The main data compilation is presented as separate data sheets indicating the material, impacting plasma species, experimental conditions, and parameterizations in terms of analytic functions

  3. Fusion plasma theory. Task I. Magnetic confinement fusion plasma theory. Final report, October 1, 1984-December 31, 1985

    International Nuclear Information System (INIS)

    Callen, J.D.

    1985-07-01

    The research performed under this contract over the current 15 month period has concentrated on some key Phaedrus tandem mirror plasma confinement and heating issues (ambipolar potential formation due to ICRF, second harmonic ECH, ponderomotive force effects, drift-pumping calculations, moment approach to transport), on development of tokamak neoclassical MHD theory (equations, instabilities, transport), and on some tokamak-specific topics (ballooning modes on a divertor separatrix, equilibrium and resistive evolution codes for Tokapole II). Progress in these and some other miscellaneous areas are briefly summarized in this final progress report for this contract, which is to evolve into a special research grant in the future

  4. Fusion, space and solar plasmas as complex systems

    International Nuclear Information System (INIS)

    Dendy, R O; Chapman, S C; Paczuski, M

    2007-01-01

    Complex systems science seeks to identify simple universal models that capture the key physics of extended macroscopic systems, whose behaviour is governed by multiple nonlinear coupled processes that operate across a wide range of spatiotemporal scales. In such systems, it is often the case that energy release occurs intermittently, in bursty events, and the phenomenology can exhibit scaling, that is a significant degree of self-similarity. Within plasma physics, such systems include Earth's magnetosphere, the solar corona and toroidal magnetic confinement experiments. Guided by broad understanding of the dominant plasma processes-for example, turbulent transport in tokamaks or reconnection in some space and solar contexts-one may construct minimalist complex systems models that yield relevant global behaviour. Examples considered here include the sandpile approach to tokamaks and the magnetosphere and a multiple loops model for the solar coronal magnetic carpet. Such models can address questions that are inaccessible to analytical treatment and are too demanding for contemporary computational resources; thus they potentially yield new insights, but risk being simplistic. Central to the utility of these models is their capacity to replicate distinctive aspects of observed global phenomenology, often strongly nonlinear, or of event statistics, for which no explanation can be obtained from first principles considerations such as the underlying equations. For example, a sandpile model, which embodies critical-gradient-triggered avalanching transport associated with nearest-neighbour mode coupling and simple boundary conditions (and little else), can be used to generate some of the distinctive observed elements of tokamak confinement phenomenology such as ELMing and edge pedestals. The same sandpile model can also generate distributions of energy-release events whose distinctive statistics resemble those observed in the auroral zone. Similarly, a multiple loops model

  5. Fast Particle Interaction With Waves In Fusion Plasmas

    International Nuclear Information System (INIS)

    Breizman, Boris

    2006-01-01

    There are two well-known motivations for theoretical studies of fast particle interaction with waves in magnetic confinement devices. One is the challenge of avoiding strong collective losses of alpha particles and beam ions in future burning plasma experiments. The other one is the compelling need to quantitatively interpret the large amount of experimental data from JET, TFTR, JT-60U, DIII-D, and other machines. Such interpretation involves unique diagnostic opportunities offered by MHD spectroscopy. This report discusses how the present theory responds to the stated challenges and what theoretical and computational advances are required to address the outstanding problems. More specifically, this paper deals with the following topics: predictive capabilities of linear theory and simulations; theory of Alfven cascades; diagnostic opportunities based on linear and nonlinear properties of unstable modes; interplay of kinetic and fluid nonlinearities; fast chirping phenomena for non-perturbative modes; and global transport of fast particles. Recent results are presented on some of the listed topics, although the main goal is to identify critical issues for future work

  6. Plasma driving system requirements for commercial tokamak fusion reactors

    International Nuclear Information System (INIS)

    Brooks, J.N.; Kustom, R.C.; Stacey, W.M. Jr.

    1978-01-01

    The plasma driving system for a tokamak reactor is composed of an ohmic heating (OH) coil, equilibrium field (EF) coil, and their respective power supplies. Conceptual designs of an Experimental Power Reactor (EPR) and scoping studies of a Demonstration Power Reactor have shown that the driving system constitutes a significant part of the overall reactor cost. The capabilities of the driving system also set or help set important parameters of the burn cycle, such as the startup time, and the net power output. Previous detailed studies on driving system dynamics have helped to define the required characteristics for fast-pulsed superconducting magnets, homopolar generators, and very high power (GVA) power supplies for an EPR. This paper summarizes results for a single reactor configuration together with several design concepts for the driving system. Both the reactor configuration and the driving system concepts are natural extensions from the EPR. Thus, the new results presented in this paper can be compared with the previous EPR results to obtain a consistent picture of how the driving system requirements will evolve--for one particular design configuration

  7. Plasma driving system requirements for commercial tokamak fusion reactors

    International Nuclear Information System (INIS)

    Brooks, J.N.; Kustom, R.C.; Stacey, W.M. Jr.

    1977-01-01

    The plasma driving system for a tokamak reactor is composed of an ohmic heating (OH) coil, equilibrium field (EF) coil, and their respective power supplies. Conceptual designs of an Experimental Power Reactor (EPR) and scoping studies of a Demonstration Power Reactor have shown that the driving system constitutes a significant part of the overall reactor cost. The capabilities of the driving system also set or help set important parameters of the burn cycle, such as the startup time, and the net power output. Previous detailed studies on driving system dynamics have helped to define the required characteristics for fast-pulsed superconducting magnets, homopolar generators, and very high power (GVA) power supplies for an EPR. This paper summarizes results for a single reactor configuration together with several design concepts for the driving system. Both the reactor configuration and the driving system concepts are natural extensions from the EPR. Thus, the new results can be compared with the previous EPR results to obtain a consistent picture of how the driving system requirements will evolve--for one particular design configuration

  8. Forthcoming Break-Even Conditions of Tokamak Plasma Performance for Fusion Energy Development

    Science.gov (United States)

    Hiwatari, Ryoji; Okano, Kunihiko; Asaoka, Yoshiyuki; Tokimatsu, Koji; Konishi, Satoshi; Ogawa, Yuichi

    The present study reveals forthcoming break-even conditions of tokamak plasma performance for the fusion energy development. The first condition is the electric break-even condition, which means that the gross electric power generation is equal to the circulating power in a power plant. This is required for fusion energy to be recognized as a suitable candidate for an alternative energy source. As for the plasma performance (normalized beta value ΒN), confinement improvement factor for H-mode HH, the ratio of plasma density to Greenwald density fnGW), the electric break-even condition requires the simultaneous achievement of 1.2 market. By using a long-term world energy scenario, a break-even price for introduction of fusion energy in the year 2050 is estimated to lie between 65 mill/kWh and 135 mill/kWh under the constraint of 550 ppm CO2 concentration in the atmosphere. In the present study, this break-even price is applied to the economic break-even condition. However, because this break-even price is based on the present energy scenario including uncertainties, the economic break-even condition discussed here should not be considered the sufficient condition, but a necessary condition. Under the conditions of Btmax = 16 T, ηe = 40 %, plant availability 60 %, and a radial build with/without CS coil, the economic break-even condition requires ΒN ˜ 5.0 for 65 mill/kWh of lower break-even price case. Finally, the present study reveals that the demonstration of steady-state operation with ΒN ˜ 3.0 in the ITER project leads to the upper region of the break-even price in the present world energy scenario, which implies that it is necessary to improve the plasma performance beyond that of the ITER advanced plasma operation.

  9. A review of laser–plasma interaction physics of indirect-drive fusion

    International Nuclear Information System (INIS)

    Kirkwood, R K; Moody, J D; Dewald, E; Glenzer, S; Divol, L; Michel, P; Hinkel, D; Berger, R; Williams, E; Milovich, J; MacGowan, B; Landen, O; Rosen, M; Lindl, J; Kline, J; Yin, L; Rose, H

    2013-01-01

    The National Ignition Facility (NIF) has been designed, constructed and has recently begun operation to investigate the ignition of nuclear fusion with a laser with up to 1.8 MJ of energy per pulse. The concept for fusion ignition on the NIF, as first proposed in 1990, was based on an indirectly driven spherical capsule of fuel in a high-Z hohlraum cavity filled with low-Z gas (Lindl et al 2004 Phys. Plasmas 11 339). The incident laser energy is converted to x-rays with keV energy on the hohlraums interior wall. The x-rays then impinge on the surface of the capsule, imploding it and producing the fuel conditions needed for ignition. It was recognized at the inception that this approach would potentially be susceptible to scattering of the incident light by the plasma created in the gas and the ablated material in the hohlraum interior. Prior to initial NIF operations, expectations for laser–plasma interaction (LPI) in ignition-scale experiments were based on experimentally benchmarked simulations and models of the plasma effects that had been carried out as part of the original proposal for NIF and expanded during the 13-year design and construction period. The studies developed the understanding of the stimulated Brillouin scatter, stimulated Raman scatter and filamentation that can be driven by the intense beams. These processes produce scatter primarily in both the forward and backward direction, and by both individual beams and collective interaction of multiple beams. Processes such as hot electron production and plasma formation and transport were also studied. The understanding of the processes so developed was the basis for the design and planning of the recent experiments in the ignition campaign at NIF, and not only indicated that the plasma instabilities could be controlled to maximize coupling, but predicted that, for the first time, they would be beneficial in controlling drive symmetry. The understanding is also now a critical component in the

  10. Experimental investigation of opacity models for stellar interior, inertial fusion, and high energy density plasmas

    International Nuclear Information System (INIS)

    Bailey, J. E.; Rochau, G. A.; Mancini, R. C.; Iglesias, C. A.; MacFarlane, J. J.; Golovkin, I. E.; Blancard, C.; Cosse, Ph.; Faussurier, G.

    2009-01-01

    Theoretical opacities are required for calculating energy transport in plasmas. In particular, understanding stellar interiors, inertial fusion, and Z pinches depends on the opacities of mid-atomic-number elements over a wide range of temperatures. The 150-300 eV temperature range is particularly interesting. The opacity models are complex and experimental validation is crucial. For example, solar models presently disagree with helioseismology and one possible explanation is inadequate theoretical opacities. Testing these opacities requires well-characterized plasmas at temperatures high enough to produce the ion charge states that exist in the sun. Typical opacity experiments heat a sample using x rays and measure the spectrally resolved transmission with a backlight. The difficulty grows as the temperature increases because the heating x-ray source must supply more energy and the backlight must be bright enough to overwhelm the plasma self-emission. These problems can be overcome with the new generation of high energy density (HED) facilities. For example, recent experiments at Sandia's Z facility [M. K. Matzen et al., Phys. Plasmas 12, 055503 (2005)] measured the transmission of a mixed Mg and Fe plasma heated to 156±6 eV. This capability will also advance opacity science for other HED plasmas. This tutorial reviews experimental methods for testing opacity models, including experiment design, transmission measurement methods, accuracy evaluation, and plasma diagnostics. The solar interior serves as a focal problem and Z facility experiments illustrate the techniques.

  11. The materials irradiation experiment for testing plasma facing materials at fusion relevant conditions

    Energy Technology Data Exchange (ETDEWEB)

    Garrison, L. M., E-mail: garrisonlm@ornl.gov; Egle, B. J. [Oak Ridge National Laboratory, 1 Bethel Valley Road, Oak Ridge, Tennessee 37831 (United States); Fusion Technology Institute, University of Wisconsin-Madison, 1500 Engineering Drive, Madison, Wisconsin 53706 (United States); Zenobia, S. J.; Kulcinski, G. L.; Santarius, J. F. [Fusion Technology Institute, University of Wisconsin-Madison, 1500 Engineering Drive, Madison, Wisconsin 53706 (United States)

    2016-08-15

    The Materials Irradiation Experiment (MITE-E) was constructed at the University of Wisconsin-Madison Inertial Electrostatic Confinement Laboratory to test materials for potential use as plasma-facing materials (PFMs) in fusion reactors. PFMs in fusion reactors will be bombarded with x-rays, neutrons, and ions of hydrogen and helium. More needs to be understood about the interactions between the plasma and the materials to validate their use for fusion reactors. The MITE-E simulates some of the fusion reactor conditions by holding samples at temperatures up to 1000 °C while irradiating them with helium or deuterium ions with energies from 10 to 150 keV. The ion gun can irradiate the samples with ion currents of 20 μA–500 μA; the typical current used is 72 μA, which is an average flux of 9 × 10{sup 14} ions/(cm{sup 2} s). The ion gun uses electrostatic lenses to extract and shape the ion beam. A variable power (1-20 W), steady-state, Nd:YAG laser provides additional heating to maintain a constant sample temperature during irradiations. The ion beam current reaching the sample is directly measured and monitored in real-time during irradiations. The ion beam profile has been investigated using a copper sample sputtering experiment. The MITE-E has successfully been used to irradiate polycrystalline and single crystal tungsten samples with helium ions and will continue to be a source of important data for plasma interactions with materials.

  12. Collision excitation studies useful for plasma diagnostics in astrophysics and fusion research

    International Nuclear Information System (INIS)

    Man Mohan; Aggarwal, Sunny

    2015-01-01

    The urgent research for energy sources has led many countries to collaborate on demonstrating the scientific and technological feasibility of magnetic fusion through the construction of International Thermonuclear Experimental Reactor in France. Data on highly charged ions with high Z will be important in this quest. Atomic data such as energy levels, radiative rates and collision excitation plays an important role in fusion research and extensive knowledge of atomic parameters is needed for plasma diagnostics. There is a very limited knowledge so far about the heavy atoms due to involvement of strong relativistic effects. For heavy atoms, electron correlation effects and relativistic effects are strongly coupled making it necessary to use a relativistic theory which also incorporates 'electron correlations effects on the same footing. For treating heavy atoms there have been new developments and many codes in the relativistic domain have been developed by various authors. Among them, multi-configuration Hartree (Dirac) Fock (MCDF) model based codes have been found very useful in ab-initio investigations. We have calculated the energy levels, radiative rates and lifetimes for heavy charged F, Na and Mg like tungsten ions using MCDF and FAC and compared our results with the other available theoretical and experimental results. Also, we have performed collision excitation calculations for F, Na and Mg like tungsten ions which will be useful for astrophysical and fusion, plasma. Also, we have compared our collision excitation results with distorted wave calculations and they are found to be in good agreement. The main goal of this paper is to provide useful atomic physics data for use in fusion research and in astrophysical and industrial plasmas. (author)

  13. Modifications of the laser beam coherence inertial confinement fusion plasmas; Modifications des proprietes de coherence des faisceaux laser dans les plasmas de fusion par confinement inertiel

    Energy Technology Data Exchange (ETDEWEB)

    Grech, M

    2007-06-15

    Inertial confinement fusion by laser requires smoothed laser beam with well-controlled coherence properties. Such beams are made of many randomly distributed intensity maxima: the so-called speckles. As the laser beam propagates through plasma its temporal and spatial coherence can be reduced. This phenomenon is called plasma induced smoothing. For high laser intensities, instabilities developing independently inside the speckles are responsible for the coherence loss. At lower intensities, only collective effects, involving many speckles, can lead to induced smoothing. This thesis is a theoretical, numerical and experimental study of these mechanisms. Accounting for the partially incoherent behavior of the laser beams requires the use of statistical description of the laser-plasma interaction. A model is developed for the multiple scattering of the laser light on the self-induced density perturbations that is responsible for a spreading of the temporal and spatial spectra of the transmitted light. It also serves as a strong seed for the instability of forward stimulated Brillouin scattering that induces both, angular spreading and red-shift of the transmitted light. A statistical model is developed for this instability. A criterion is obtained that gives a laser power (below the critical power for filamentation) above which the instability growth is important. Numerical simulations with the interaction code PARAX and an experiment performed on the ALISE laser facility confirm the importance of these forward scattering mechanisms in the modification of the laser coherence properties. (author)

  14. Application of diffusion theory to the transport of neutral particles in fusion plasmas

    International Nuclear Information System (INIS)

    Hasan, M.Z.

    1985-01-01

    It is shown that the widely held view that diffusion theory can not provide good accuracy for the transport of neutral particles in fusion plasmas is misplaced. In fact, it is shown that multigroup diffusion theory gives quite good accuracy as compared to the transport theory. The reasons for this are elaborated and some of the physical and theoretical reasons which make the multigroup diffusion theory provide good accuracy are explained. Energy dependence must be taken into consideration to obtain a realistic neutral atom distribution in fusion plasmas. There are two reasons for this; presence of either is enough to necessitate an energy dependent treatment. First, the plasma temperature varies spatially, and second, the ratio of charge-exchange to total plasma-neutral interaction cross section (c) is not close to one. A computer code to solve the one-dimensional multigroup diffusion theory in general geometry (slab, cylindrical and spherical) has been written for use on Cray computers, and its results are compared with those from the one-dimensional transport code ANISN to support the above finding. A fast, compact and versatile two-dimensional finite element multigroup diffusion theory code, FINAT, in X-Y and R-Z cylindrical/toroidal geometries has been written for use on CRAY computers. This code has been compared with the two dimensional transport code DOT-4.3. The accuracy is very good, and FENAT runs much faster compared even to DOT-4.3 which is a finite difference code

  15. Application of spatially resolved high resolution crystal spectrometry to inertial confinement fusion plasmas.

    Science.gov (United States)

    Hill, K W; Bitter, M; Delgado-Aparacio, L; Pablant, N A; Beiersdorfer, P; Schneider, M; Widmann, K; Sanchez del Rio, M; Zhang, L

    2012-10-01

    High resolution (λ∕Δλ ∼ 10 000) 1D imaging x-ray spectroscopy using a spherically bent crystal and a 2D hybrid pixel array detector is used world wide for Doppler measurements of ion-temperature and plasma flow-velocity profiles in magnetic confinement fusion plasmas. Meter sized plasmas are diagnosed with cm spatial resolution and 10 ms time resolution. This concept can also be used as a diagnostic of small sources, such as inertial confinement fusion plasmas and targets on x-ray light source beam lines, with spatial resolution of micrometers, as demonstrated by laboratory experiments using a 250-μm (55)Fe source, and by ray-tracing calculations. Throughput calculations agree with measurements, and predict detector counts in the range 10(-8)-10(-6) times source x-rays, depending on crystal reflectivity and spectrometer geometry. Results of the lab demonstrations, application of the technique to the National Ignition Facility (NIF), and predictions of performance on NIF will be presented.

  16. Liquid Metals as Plasma-facing Materials for Fusion Energy Systems: From Atoms to Tokamaks

    Energy Technology Data Exchange (ETDEWEB)

    Stone, Howard A. [Princeton Univ., NJ (United States); Koel, Bruce E. [Princeton Univ., NJ (United States); Bernasek, Steven L. [Princeton Univ., NJ (United States); Carter, Emily A. [Princeton Univ., NJ (United States); Debenedetti, Pablo G. [Princeton Univ., NJ (United States); Panagiotopoulos, Athanassios Z. [Princeton Univ., NJ (United States)

    2017-06-23

    The objective of our studies was to advance our fundamental understanding of liquid metals as plasma-facing materials for fusion energy systems, with a broad scope: from atoms to tokamaks. The flow of liquid metals offers solutions to significant problems of the plasma-facing materials for fusion energy systems. Candidate metals include lithium, tin, gallium, and their eutectic combinations. However, such liquid metal solutions can only be designed efficiently if a range of scientific and engineering issues are resolved that require advances in fundamental fluid dynamics, materials science and surface science. In our research we investigated a range of significant and timely problems relevant to current and proposed engineering designs for fusion reactors, including high-heat flux configurations that are being considered by leading fusion energy groups world-wide. Using experimental and theoretical tools spanning atomistic to continuum descriptions of liquid metals, and bridging surface chemistry, wetting/dewetting and flow, our research has advanced the science and engineering of fusion energy materials and systems. Specifically, we developed a combined experimental and theoretical program to investigate flows of liquid metals in fusion-relevant geometries, including equilibrium and stability of thin-film flows, e.g. wetting and dewetting, effects of electromagnetic and thermocapillary fields on liquid metal thin-film flows, and how chemical interactions and the properties of the surface are influenced by impurities and in turn affect the surface wetting characteristics, the surface tension, and its gradients. Because high-heat flux configurations produce evaporation and sputtering, which forces rearrangement of the liquid, and any dewetting exposes the substrate to damage from the plasma, our studies addressed such evaporatively driven liquid flows and measured and simulated properties of the different bulk phases and material interfaces. The range of our studies

  17. Collective laser light scattering from electron density fluctuations in fusion research plasmas (invited)

    International Nuclear Information System (INIS)

    Holzhauer, E.; Dodel, G.

    1990-01-01

    In magnetically confined plasmas density fluctuations of apparently turbulent nature with broad spectra in wave number and frequency space are observed which are thought to be the cause for anomalous energy and particle transport across the confining magnetic field. Collective laser light scattering has been used to study the nature of these fluctuations. Specific problems of scattering from fusion plasmas are addressed and illustrated with experimental results from the 119 μm far infrared laser scattering experiment operated on the ASDEX tokamak. Using the system in the heterodyne mode the direction of propagation with respect to the laboratory frame can be determined. Spatial resolution has bean improved by making use of the change in pitch of the total magnetic field across the minor plasma radius. Special emphasis is placed on the ohmic phase where a number of parameter variations including electron density, electron temperature, toroidal magnetic field, and filling gas were performed

  18. Spectra of neutrons and fusion charged products produced in a dense laser plasma

    International Nuclear Information System (INIS)

    Burtsev, V.A.; Dyatlov, V.D.; Krzhizhanovskij, R.E.; Levkovskij, A.A.

    1977-01-01

    The possibility of laser-produced plasma diagnostics has been investigated by measuring spectra of neutrons and alpha particles produced in the T(d,n) 4 He reaction. Using the Monte Carlo method the spectra have been calculated for nine states of the deuterium-tritium plasma with the temperature of 1;5 and 10 keV and the density of 0.2; 1 and 10 g/cm 3 respectively. The initial radius of the target was assumed to be 0.01 cm at the density of 0.2 g/cm 3 . It is shown that the neutron and alpha spectra can serve as plasma diagnostics parameters in laser fusion

  19. Improved Frequency Fluctuation Model for Spectral Line Shape Calculations in Fusion Plasmas

    International Nuclear Information System (INIS)

    Ferri, S.; Calisti, A.; Mosse, C.; Talin, B.; Lisitsa, V.

    2010-01-01

    A very fast method to calculate spectral line shapes emitted by plasmas accounting for charge particle dynamics and effects of an external magnetic field is proposed. This method relies on a new formulation of the Frequency Fluctuation Model (FFM), which yields to an expression of the dynamic line profile as a functional of the static distribution function of frequencies. This highly efficient formalism, not limited to hydrogen-like systems, allows to calculate pure Stark and Stark-Zeeman line shapes for a wide range of density, temperature and magnetic field values, which is of importance in plasma physics and astrophysics. Various applications of this method are presented for conditions related to fusion plasmas.

  20. Determination of the Tritium Concentration in Deuterium-Tritium Fusion Plasmas from the Jet TTE Campaign

    International Nuclear Information System (INIS)

    Gatu Johnson, Maria

    2004-01-01

    This thesis describes the development and implementation of methods for tritium concentration determination for JET fusion plasmas. The usefulness of MPR data in this context is investigated. It is shown that results from MPR spectral analysis can simplify the calculations for neutral beam heated plasmas and that it is essential for calculations for radio frequency heated plasmas. The described methods are applied to pulses from the Trace Tritium Experiment (TTE), staged at JET in October 2003. Results from simple, time resolved analysis using MPR and other public JET data are presented and the assumptions made in the calculations are discussed. The results agree with expectations but would be even more interesting if spatial variations were taken into account

  1. Determination of the Tritium Concentration in Deuterium-Tritium Fusion Plasmas from the Jet TTE Campaign

    Energy Technology Data Exchange (ETDEWEB)

    Gatu Johnson, Maria

    2004-01-01

    This thesis describes the development and implementation of methods for tritium concentration determination for JET fusion plasmas. The usefulness of MPR data in this context is investigated. It is shown that results from MPR spectral analysis can simplify the calculations for neutral beam heated plasmas and that it is essential for calculations for radio frequency heated plasmas. The described methods are applied to pulses from the Trace Tritium Experiment (TTE), staged at JET in October 2003. Results from simple, time resolved analysis using MPR and other public JET data are presented and the assumptions made in the calculations are discussed. The results agree with expectations but would be even more interesting if spatial variations were taken into account.

  2. Plasma exposure behavior of re-deposited tungsten on structural materials of fusion reactors

    Energy Technology Data Exchange (ETDEWEB)

    Xu, Yu-Ping; Wang, Jing [Institute of Plasma Physics, Chinese Academy of Sciences, Hefei 230031 (China); Science Island Branch of Graduate School, University of Science & Technology of China, Hefei 230031 (China); Zhou, Hai-Shan, E-mail: haishanzhou@ipp.ac.cn [Institute of Plasma Physics, Chinese Academy of Sciences, Hefei 230031 (China); Liu, Feng [Institute of Plasma Physics, Chinese Academy of Sciences, Hefei 230031 (China); Li, Zeng-De [General Research Institute for Nonferrous Metals, Beijing 100088 (China); Li, Xiao-Chun; Lu, Tao [Institute of Plasma Physics, Chinese Academy of Sciences, Hefei 230031 (China); Liu, Hao-Dong [Institute of Plasma Physics, Chinese Academy of Sciences, Hefei 230031 (China); Science Island Branch of Graduate School, University of Science & Technology of China, Hefei 230031 (China); Ding, Fang; Mao, Hong-Min; Zhao, Ming-Zhong [Institute of Plasma Physics, Chinese Academy of Sciences, Hefei 230031 (China); Lin, Chen-Guang [General Research Institute for Nonferrous Metals, Beijing 100088 (China); Luo, Guang-Nan [Institute of Plasma Physics, Chinese Academy of Sciences, Hefei 230031 (China); Science Island Branch of Graduate School, University of Science & Technology of China, Hefei 230031 (China); Hefei Center for Physical Science and Technology, Hefei 230031 (China); Hefei Science Center of Chinese Academy of Science, Hefei 230027 (China)

    2017-05-15

    To evaluate the effects of re-deposited tungsten (W) on the surface modification and hydrogen isotope retention behavior of fusion structural materials, the plasma exposure behavior of re-deposited W samples prepared by magnetron sputtering on the F82H steel, the V-5Cr-5Ti alloy as well as bare substrate samples was investigated. All the samples were exposed to 367 shots of deuterium plasmas in the 2015 spring EAST campaign. After the plasma exposure, large area of W layer was exfoliated, while big blisters were found at the interface between the remaining W layer and the substrate materials. The deuterium retention behavior of the samples with re-deposited W layer was characterized by thermal desorption spectroscopy and compared with the bare substrate samples.

  3. Assessment of ion-atom collision data for magnetic fusion plasma edge modelling

    International Nuclear Information System (INIS)

    Phaneuf, R.A.

    1990-01-01

    Cross-section data for ion-atom collision processes which play important roles in the edge plasma of magnetically-confined fusion devices are surveyed and reviewed. The species considered include H, He, Li, Be, C, O, Ne, Al, Si, Ar, Ti, Cr, Fe, Ni, Cu, Mo, W and their ions. The most important ion-atom collision processes occurring in the edge plasma are charge-exchange reactions. Excitation and ionization processes are also considered. The scope is limited to atomic species and to collision velocities corresponding to plasma ion temperatures in the 2-200 eV range. Sources of evaluated or recommended data are presented where possible, and deficiencies in the data base are indicated. 42 refs., 1 fig., 4 tabs

  4. Advanced real-time control systems for magnetically confined fusion plasmas

    International Nuclear Information System (INIS)

    Goncalves, B.; Sousa, J.; Fernandes, H.; Rodrigues, A.P.; Carvalho, B.B.; Neto, A.; Varandas, C.A.F.

    2008-01-01

    Real-time control of magnetically confined plasmas is a critical issue for the safety, operation and high performance scientific exploitation of the experimental devices on regimes beyond the current operation frontiers. The number of parameters and the data volumes used for the plasma properties identification scale normally not only with the machine size but also with the technology improvements, leading to a great complexity of the plant system. A strong computational power and fast communication infrastructure are needed to handle in real-time this information, allowing just-in-time decisions to achieve the fusion critical plasma conditions. These advanced control systems require a tiered infrastructure including the hardware layer, the signal-processing middleware, real-time timing and data transport, the real-time operating system tools and drivers, the framework for code development, simulation, deployment and experiment parameterization and the human real-time plasma condition monitoring and management. This approach is being implemented at CFN by offering a vertical solution for the forthcoming challenges, including ITER, the first experimental fusion reactor. A given set of tools and systems are described on this paper, namely: (i) an ATCA based hardware multiple-input-multiple-output (MIMO) platform, PCI and PCIe acquisition and control modules; (ii) FPGA and DSP parallelized signal processing algorithms; (iii) a signal data and event distribution system over a 2.5/10Gb optical network with sub-microsecond latencies; (iv) RTAI and Linux drivers; and (v) the FireSignal, FusionTalk, SDAS FireCalc application tools. (author)

  5. D-D nuclear fusion processes induced in polyethylene foams by TW Laser-generated plasma

    Directory of Open Access Journals (Sweden)

    Torrisi L.

    2015-01-01

    Full Text Available Deuterium-Deuterium fusion processes were generated by focusing the 3 TW PALS Laser on solid deuterated polyethylene targets placed in vacuum. Deuterium ion acceleration of the order of 4 MeV was obtained using laser irradiance Iλ2 ∼ 5 × 1016 W μm2/cm2 on the target. Thin and thick targets, at low and high density, were irradiated and plasma properties were monitored “on line” and “off line”. The ion emission from plasma was monitored with Thomson Parabola Spectrometer, track detectors and ion collectors. Fast semiconductor detectors based on SiC and fast plastic scintillators, both employed in time-of-flight configuration, have permitted to detect the characteristic 3.0 MeV protons and 2.45 MeV neutrons emission from the nuclear fusion reactions. From massive absorbent targets we have evaluated the neutron flux by varying from negligible values up to about 5 × 107 neutrons per laser shot in the case of foams targets, indicating a reaction rate of the order of 108 fusion events per laser shot using “advanced targets”.

  6. The potential role of electric fields and plasma barodiffusion on the inertial confinement fusion databasea)

    Science.gov (United States)

    Amendt, Peter; Wilks, S. C.; Bellei, C.; Li, C. K.; Petrasso, R. D.

    2011-05-01

    The generation of strong, self-generated electric fields (GV/m) in direct-drive, inertial-confinement-fusion (ICF) capsules has been reported [Rygg et al., Science 319, 1223 (2008); Li et al., Phys. Rev. Lett. 100, 225001 (2008)]. A candidate explanation for the origin of these fields based on charge separation across a plasma shock front was recently proposed [Amendt et al., Plasma Phys. Controlled Fusion 51 124048 (2009)]. The question arises whether such electric fields in imploding capsules can have observable consequences on target performance. Two well-known anomalies come to mind: (1) an observed ≈2× greater-than-expected deficit of neutrons in an equimolar D3He fuel mixture compared with hydrodynamically equivalent D [Rygg et al., Phys. Plasmas 13, 052702 (2006)] and DT [Herrmann et al., Phys. Plasmas 16, 056312 (2009)] fuels, and (2) a similar shortfall of neutrons when trace amounts of argon are mixed with D in indirect-drive implosions [Lindl et al., Phys. Plasmas 11, 339 (2004)]. A new mechanism based on barodiffusion (or pressure gradient-driven diffusion) in a plasma is proposed that incorporates the presence of shock-generated electric fields to explain the reported anomalies. For implosions performed at the Omega laser facility [Boehly et al., Opt. Commun. 133, 495 (1997)], the (low Mach number) return shock has an appreciable scale length over which the lighter D ions can diffuse away from fuel center. The depletion of D fuel is estimated and found to lead to a corresponding reduction in neutrons, consistent with the anomalies observed in experiments for both argon-doped D fuels and D3He equimolar mixtures. The reverse diffusional flux of the heavier ions toward fuel center also increases the pressure from a concomitant increase in electron number density, resulting in lower stagnation pressures and larger imploded cores in agreement with gated, self-emission, x-ray imaging data.

  7. Millimeter-wave imaging of magnetic fusion plasmas: technology innovations advancing physics understanding

    Science.gov (United States)

    Wang, Y.; Tobias, B.; Chang, Y.-T.; Yu, J.-H.; Li, M.; Hu, F.; Chen, M.; Mamidanna, M.; Phan, T.; Pham, A.-V.; Gu, J.; Liu, X.; Zhu, Y.; Domier, C. W.; Shi, L.; Valeo, E.; Kramer, G. J.; Kuwahara, D.; Nagayama, Y.; Mase, A.; Luhmann, N. C., Jr.

    2017-07-01

    Electron cyclotron emission (ECE) imaging is a passive radiometric technique that measures electron temperature fluctuations; and microwave imaging reflectometry (MIR) is an active radar imaging technique that measures electron density fluctuations. Microwave imaging diagnostic instruments employing these techniques have made important contributions to fusion science and have been adopted at major fusion facilities worldwide including DIII-D, EAST, ASDEX Upgrade, HL-2A, KSTAR, LHD, and J-TEXT. In this paper, we describe the development status of three major technological advancements: custom mm-wave integrated circuits (ICs), digital beamforming (DBF), and synthetic diagnostic modeling (SDM). These have the potential to greatly advance microwave fusion plasma imaging, enabling compact and low-noise transceiver systems with real-time, fast tracking ability to address critical fusion physics issues, including ELM suppression and disruptions in the ITER baseline scenario, naturally ELM-free states such as QH-mode, and energetic particle confinement (i.e. Alfvén eigenmode stability) in high-performance regimes that include steady-state and advanced tokamak scenarios. Furthermore, these systems are fully compatible with today’s most challenging non-inductive heating and current drive systems and capable of operating in harsh environments, making them the ideal approach for diagnosing long-pulse and steady-state tokamaks.

  8. Energetic Particle Physics In Fusion Research In Preparation For Burning Plasma Experiments

    Energy Technology Data Exchange (ETDEWEB)

    Gorelenkov, Nikolai N [PPPL

    2013-06-01

    The area of energetic particle (EP) physics of fusion research has been actively and extensively researched in recent decades. The progress achieved in advancing and understanding EP physics has been substantial since the last comprehensive review on this topic by W.W. Heidbrink and G.J. Sadler [1]. That review coincided with the start of deuterium-tritium (DT) experiments on Tokamak Fusion Test reactor (TFTR) and full scale fusion alphas physics studies. Fusion research in recent years has been influenced by EP physics in many ways including the limitations imposed by the "sea" of Alfven eigenmodes (AE) in particular by the toroidicityinduced AEs (TAE) modes and reversed shear Alfven (RSAE). In present paper we attempt a broad review of EP physics progress in tokamaks and spherical tori since the first DT experiments on TFTR and JET (Joint European Torus) including helical/stellarator devices. Introductory discussions on basic ingredients of EP physics, i.e. particle orbits in STs, fundamental diagnostic techniques of EPs and instabilities, wave particle resonances and others are given to help understanding the advanced topics of EP physics. At the end we cover important and interesting physics issues toward the burning plasma experiments such as ITER (International Thermonuclear Experimental Reactor).

  9. Refraction-enhanced backlit imaging of axially symmetric inertial confinement fusion plasmas.

    Science.gov (United States)

    Koch, Jeffrey A; Landen, Otto L; Suter, Laurence J; Masse, Laurent P; Clark, Daniel S; Ross, James S; Mackinnon, Andrew J; Meezan, Nathan B; Thomas, Cliff A; Ping, Yuan

    2013-05-20

    X-ray backlit radiographs of dense plasma shells can be significantly altered by refraction of x rays that would otherwise travel straight-ray paths, and this effect can be a powerful tool for diagnosing the spatial structure of the plasma being radiographed. We explore the conditions under which refraction effects may be observed, and we use analytical and numerical approaches to quantify these effects for one-dimensional radial opacity and density profiles characteristic of inertial-confinement fusion (ICF) implosions. We also show how analytical and numerical approaches allow approximate radial plasma opacity and density profiles to be inferred from point-projection refraction-enhanced radiography data. This imaging technique can provide unique data on electron density profiles in ICF plasmas that cannot be obtained using other techniques, and the uniform illumination provided by point-like x-ray backlighters eliminates a significant source of uncertainty in inferences of plasma opacity profiles from area-backlit pinhole imaging data when the backlight spatial profile cannot be independently characterized. The technique is particularly suited to in-flight radiography of imploding low-opacity shells surrounding hydrogen ice, because refraction is sensitive to the electron density of the hydrogen plasma even when it is invisible to absorption radiography. It may also provide an alternative approach to timing shockwaves created by the implosion drive, that are currently invisible to absorption radiography.

  10. A Novel Spectrometer for Measuring Laser-Produced Plasma X-Ray in Inertial Confinement Fusion

    Directory of Open Access Journals (Sweden)

    Zhu Gang

    2012-01-01

    Full Text Available In the experimental investigations of inertial confinement fusion, the laser-produced high-temperature plasma contains very abundant information, such as the electron temperature and density, ionization. In order to diagnose laser-plasma distribution in space and evolution in time, an elliptical curved crystal spectrometer has been developed and applied to diagnose X-ray of laser-produced plasma in 0.2~2.46 nm region. According to the theory of Bragg diffraction, four kinds of crystal including LiF, PET, MiCa, and KAP were chosen as dispersive elements. The distance of crystal lattice varies from 0.4 to 2.6 nm. Bragg angle is in the range of 30°~67.5°, and the spectral detection angle is in 55.4°~134°. The curved crystal spectrometer mainly consists of elliptical curved crystal analyzer, vacuum configuration, aligning device, spectral detectors and three-dimensional microadjustment devices. The spectrographic experiment was carried out on the XG-2 laser facility. Emission spectrum of Al plasmas, Ti plasma, and Au plasmas have been successfully recorded by using X-ray CCD camera. It is demonstrated experimentally that the measured wavelength is accorded with the theoretical value.

  11. Joint Varenna-Lausanne International Workshop on the Theory of Fusion Plasmas 2016

    International Nuclear Information System (INIS)

    2016-01-01

    The joint Varenna-Lausanne international workshop on the theory of fusion plasmas took place in Varenna from August 29 to September 2 2016. Several issues of interest for fusion plasmas were addressed, namely MHD stability, RF heating, collisional and turbulent transport, plasma wall interaction, and physics of burning plasmas. The articles published in this special issue illustrate nicely the well balanced combination of physics, applied mathematics, and computer sciences that characterizes this workshop. Let us mention several attractive topics, which are addressed in this issue. The question of 3D MHD equilibrium in tokamaks has received a great deal of attention, in connection with external resonant magnetic perturbations in tokamaks, and also stochastic edge in stellarators. The reader will also find some recent developments related to the effect of current drive and heating on the stability of tearing modes. As usual, turbulent transport is addressed in much detail. Several papers address specific numerical aspects of fluid and gyrokinetic codes, including code optimisation. Physics issues are abundantly dealt with, such as the impact of fast particles on turbulence, and particle transport. New numerical techniques to model wave propagation are presented, which provide significant advances in the field. Refinements such as the effect of density fluctuation on wave propagation, or the interaction between particles and the electromagnetic field near antennas, have also been studied in depth. Finally, specific issues such as nonlocal transport, decay of zonal flows, and the effect of neutrals on rotation have been investigated. A striking feature of the 2016 edition was the large number of young faces among the participants. This is a great satisfaction for the organizers since a new generation of scientists is certainly needed whilst several devices come to operation, or will do so in a foreseeable future. The diversity and quality of the papers published in

  12. Forthcoming break-even conditions of tokamak plasma performance for fusion energy development

    International Nuclear Information System (INIS)

    Hiwatari, Ryoji; Okano, Kunihiko; Asaoka, Yoshiyuki; Tokimatsu, Koji; Konishi, Satoshi; Ogawa, Yuichi

    2005-01-01

    The present study reveals forthcoming break-even conditions of tokamak plasma performance for the fusion energy development. The first condition is the electric break-even condition, which means that the gross electric power generation is equal to the circulating power in a power plant. This is required for fusion energy to be recognized as a suitable candidate for an alternative energy source. As for the plasma performance (normalized beta value β N , confinement improvement factor for H-mode HH, the ratio of plasma density to Greenwald density fn GW ), the electric break-even condition requires the simultaneous achievement of 1.2 N GW tmax =16 T, thermal efficiency η e =30%, and current drive power P NBI N ∼1.8, HH≠1.0, and fn GW ∼0.9, which correspond to the ITER reference operation parameters, have a strong potential to achieve the electric break-even condition. The second condition is the economic break-even condition, which is required for fusion energy to be selected as an alternative energy source in the energy market. By using a long-term world energy scenario, a break-even price for introduction of fusion energy in the year 2050 is estimated to lie between 65 mill/kWh and 135 mill/kWh under the constraint of 550 ppm CO 2 concentration in the atmosphere. In the present study, this break-even price is applied to the economic break-even condition. However, because this break-even price is based on the present energy scenario including uncertainties, the economic break-even condition discussed here should not be considered the sufficient condition, but a necessary condition. Under the conditions of B tmax =16 T, η e =40%, plant availability 60%, and a radial build with/without CS coil, the economic break-even condition requires β N ∼5.0 for 65 mill/kWh of lower break-even price case. Finally, the present study reveals that the demonstration of steady-state operation with β N ∼3.0 in the ITER project leads to the upper region of the break

  13. Extending the capabilities of the DIII-D Plasma Control System for worldwide fusion research collaborations

    International Nuclear Information System (INIS)

    Penaflor, B.G.; Ferron, J.R.; Walker, M.L.; Humphreys, D.A.; Leuer, J.A.; Piglowski, D.A.; Johnson, R.D.; Xiao, B.J.; Hahn, S.H.; Gates, D.A.

    2009-01-01

    This paper will discuss the recent enhancements which have been made to the DIII-D Plasma Control System (PCS) in order to further extend its usefulness as a shared tool for worldwide fusion research. The PCS developed at General Atomics is currently being used in a number of fusion research experiments worldwide, including the DIII-D Tokamak Facility in San Diego, and most recently the KSTAR Tokamak in South Korea. A number of enhancements have been made to support the ongoing needs of the DIII-D Tokamak in addition to meeting the needs of other PCS users worldwide. Details of the present PCS hardware and software architecture along with descriptions of the latest enhancements will be given.

  14. Properties of the ion-ion hybrid resonator in fusion plasmas

    International Nuclear Information System (INIS)

    Morales, George J.

    2015-01-01

    The project developed theoretical and numerical descriptions of the properties of ion-ion hybrid Alfvn resonators that are expected to arise in the operation of a fusion reactor. The methodology and theoretical concepts were successfully compared to observations made in basic experiments in the LAPD device at UCLA. An assessment was made of the excitation of resonator modes by energetic alpha particles for burning plasma conditions expected in the ITER device. The broader impacts included the generation of basic insight useful to magnetic fusion and space science researchers, defining new avenues for exploration in basic laboratory experiments, establishing broader contacts between experimentalists and theoreticians, completion of a Ph.D. dissertation, and promotion of interest in science through community outreach events and classroom instruction.

  15. Papers presented at the fourteenth international conference on plasma physics and controlled nuclear fusion research

    International Nuclear Information System (INIS)

    1994-01-01

    This report contains the contributions of the CIEMAT's Fusion Unit to the 14th International Conference on Plasma Physics and Controlled Nuclear Fusion Research that was held by the International Atomic Energy Agency in Wurzburg, Germany from 30 September to 7 October 1992. Three papers were presented that summarized the main lines of work done in the Unit during the previous two years: The first one on the theoretical advances in the understanding of the Flexible Heliac TJ-II under construction, the second on the confinement studies performed in the operating TJ-I Tokamak and the third one on the description of the physical properties of the soon to be started TJ-IU Torsatron. (Author) 25 refs

  16. Magnetic stochasticity in magnetically confined fusion plasmas chaos of field lines and charged particle dynamics

    CERN Document Server

    Abdullaev, Sadrilla

    2014-01-01

    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  statisti...

  17. The Rayleigh-Taylor instability in inertial fusion, astrophysical plasma and flames

    International Nuclear Information System (INIS)

    Bychkov, V; Modestov, M; Akkerman, V; Eriksson, L-E

    2007-01-01

    Previous results are reviewed and new results are presented on the Rayleigh-Taylor instability in inertial confined fusion, flames and supernovae including gravitational and thermonuclear explosion mechanisms. The instability couples micro-scale plasma effects to large-scale hydrodynamic phenomena. In inertial fusion the instability reduces target compression. In supernovae the instability produces large-scale convection, which determines the fate of the star. The instability is often accompanied by mass flux through the unstable interface, which may have either a stabilizing or a destabilizing influence. Destabilization happens due to the Darrieus-Landau instability of a deflagration front. Still, it is unclear whether the instabilities lead to well-organized large-scale structures (bubbles) or to relatively isotropic turbulence (mixing layer)

  18. Exploring liquid metal plasma facing component (PFC) concepts-Liquid metal film flow behavior under fusion relevant magnetic fields

    International Nuclear Information System (INIS)

    Narula, M.; Abdou, M.A.; Ying, A.; Morley, N.B.; Ni, M.; Miraghaie, R.; Burris, J.

    2006-01-01

    The use of fast moving liquid metal streams or 'liquid walls' as a plasma contact surface is a very attractive option and has been looked upon with considerable interest over the past several years, both by the plasma physics and fusion engineering programs. Flowing liquid walls provide an ever replenishing contact surface to the plasma, leading to very effective particle pumping and surface heat flux removal. A key feasibility issue for flowing liquid metal plasma facing component (PFC) systems, pertains to their magnetohydrodynamic (MHD) behavior under the spatially varying magnetic field environment, typical of a fusion device. MHD forces hinder the development of a smooth and controllable liquid metal flow needed for PFC applications. The present study builds up on the ongoing research effort at UCLA, directed towards providing qualitative and quantitative data on liquid metal free surface flow behavior under fusion relevant magnetic fields

  19. Comprehensive ab initio simulations of turbulence in ITER-relevant fusion plasmas

    International Nuclear Information System (INIS)

    Jenko, Frank

    2014-01-01

    The astonishing improvements achieved in supercomputing capabilities over the past two decades have allowed groundbreaking new insights into the physics of plasma turbulence. Even though much has been learned already, fundamental challenges related to predicting the performance of future fusion reactors still remain. In particular, today's fusion experiments routinely achieve a transition to a high-confinement mode (H-mode) with a strong transport barrier at the plasma boundary. Understanding the formation conditions of this barrier and its characteristic size and height are crucial to predicting the efficiency of future fusion reactors, but a fully consistent numerical treatment has still been lacking up to now. A main challenge in the treatment of such barriers is their extreme profile variation, implying their susceptibility to finite-size effects. Global simulation capabilities such as demonstrated within the framework of the present project are thus essential in order to understand the dynamics of the edge transport barrier. Both present and future projects employing the GENE code will build on the experience established within this SuperMUC project and tackle this challenging issue. Another increasingly important field relates to turbulence studies in stellarators, which represent an alternative machine design for future fusion applications. With its newly developed capability of studying turbulence in stellarator geometry (i.e. retaining magnetic geometry variations within a magnetic surface), the GENE code is uniquely suited for this problem. With the new German stellarator experiment Wendelstein 7-X nearing completion, existing predictions already made with GENE for stellarator turbulence will be put to the test, and possibilities for validation will emerge. Due to the complex magnetic geometry, stellarator turbulence simulations have extreme computational requirements and will thus continue to challenge the available supercomputing capabilities also in

  20. Development and evaluation of plasma facing materials for future thermonuclear fusion reactors

    International Nuclear Information System (INIS)

    Linke, J.; Pintsuk, G.; Roedig, M.; Schmidt, A.; Thomser, C.

    2010-01-01

    More and more attention is directed towards thermonuclear fusion as a possible future energy source. Major advantages of this energy conversion technology are the almost inexhaustible resources and the option to produce energy without CO 2 -emissions. However, in the most advanced field of magnetic plasma confinement a number of technological challenges have to be met. In particular high-temperature resistant and plasma compatible meterials have to be developed and qualified which are able to withstand the extreme environments in a commercial thermonuclear power reactor. The plasma facing materials (PEMs) and components (PFCs) in such fusion devices, i.e. the first wall (FW), the limiters and the divertor, are strongly affected by the plasma wall interaction processes and the applied intense thermal loads during plasma operation. On the one hand, these mechanisms have a strong influence on the plasma performance; on the other hand, they have major impact on the lifetime of the plasma facing armour. Materials for plasma facing components have to fulfill a number of requirements. First of all the materials have to be plasma compatible, i.e. they should exhibit a low atomic number to avoid radiative losses whenever atoms from the wall material will be ionized in the plasma. In addition, the materials must have a high melting point, a high thermal conductivity, and adequate mechanical properties. To select the most suitable material candidates, a comprehensive data base is required which includes all thermo-physical and mechanical properties. In present-day and next step devices the resulting thermal steady state heat loads to the first wall remain below 1 MWm -2 , meanwhile the limiters and the divertor are expected to be exposed to power densities being at least one order of magnitude above the FW-level, i.e. up to 20 MWm -2 for next step tokamaks such as ITER or DEMO. These requirements are responsible for high demands on the selection of qualified PFMs and heat

  1. Development and evaluation of plasma facing materials for future thermonuclear fusion reactors

    Energy Technology Data Exchange (ETDEWEB)

    Linke, J.; Pintsuk, G.; Roedig, M.; Schmidt, A.; Thomser, C. [Forschungszentrum Juelich GmbH, EURATOM Association, Juelich (Germany)

    2010-07-01

    More and more attention is directed towards thermonuclear fusion as a possible future energy source. Major advantages of this energy conversion technology are the almost inexhaustible resources and the option to produce energy without CO{sub 2}-emissions. However, in the most advanced field of magnetic plasma confinement a number of technological challenges have to be met. In particular high-temperature resistant and plasma compatible meterials have to be developed and qualified which are able to withstand the extreme environments in a commercial thermonuclear power reactor. The plasma facing materials (PEMs) and components (PFCs) in such fusion devices, i.e. the first wall (FW), the limiters and the divertor, are strongly affected by the plasma wall interaction processes and the applied intense thermal loads during plasma operation. On the one hand, these mechanisms have a strong influence on the plasma performance; on the other hand, they have major impact on the lifetime of the plasma facing armour. Materials for plasma facing components have to fulfill a number of requirements. First of all the materials have to be plasma compatible, i.e. they should exhibit a low atomic number to avoid radiative losses whenever atoms from the wall material will be ionized in the plasma. In addition, the materials must have a high melting point, a high thermal conductivity, and adequate mechanical properties. To select the most suitable material candidates, a comprehensive data base is required which includes all thermo-physical and mechanical properties. In present-day and next step devices the resulting thermal steady state heat loads to the first wall remain below 1 MWm{sup -2}, meanwhile the limiters and the divertor are expected to be exposed to power densities being at least one order of magnitude above the FW-level, i.e. up to 20 MWm{sup -2} for next step tokamaks such as ITER or DEMO. These requirements are responsible for high demands on the selection of qualified PFMs

  2. Fusion performances and alpha heating in future JET D-T plasmas

    Energy Technology Data Exchange (ETDEWEB)

    Balet, B; Cordey, J G; Gibson, A; Lomas, P; Stubberfield, P M; Thomas, P [Commission of the European Communities, Abingdon (United Kingdom). JET Joint Undertaking

    1994-07-01

    The new pump divertor installed at JET should allow high performance pulses of a few seconds duration by both preventing the impurity influx and controlling the density evolution. The TRANSP code has been used in a predictive mode to assess the possible fusion performance of such plasmas fuelled with a 50:50 mixture of D and T, and the effect of alpha particles heating on Te and Ti. Several cases are considered: 50:50 D-T mix; 50:50 D-T mix, no C bloom; 50:50 D-T mix, VH phase, density control; 50:50 D-T mix, VH phase, density control, 6 Ma. The predictions show that if the the bloom and MHD instabilities can be controlled at higher plasma currents using a higher toroidal field to keep a reasonable beta value, then a higher fusion performance steady state plasma with Q{sub DT} superior to 2.5 should be possible. The alpha heating power of 4.9 MW would lead to a 74% increase in Te. 4 refs., 4 figs., 1 tab.

  3. High-Z plasma facing components in fusion devices: boundary conditions and operational experiences

    Science.gov (United States)

    Neu, R.

    2006-04-01

    In present day fusion devices optimization of the performance and experimental freedom motivates the use of low-Z plasma facing materials (PFMs). However, in a future fusion reactor, for economic reasons, a sufficient lifetime of the first wall components is essential. Additionally, tritium retention has to be small to meet safety requirements. Tungsten appears to be the most realistic material choice for reactor plasma facing components (PFCs) because it exhibits the lowest erosion. But besides this there are a lot of criteria which have to be fulfilled simultaneously in a reactor. Results from present day devices and from laboratory experiments confirm the advantages of high-Z PFMs but also point to operational restrictions, when using them as PFCs. These are associated with the central impurity concentration, which is determined by the sputtering yield, the penetration of the impurities and their transport within the confined plasma. The restrictions could exclude successful operation of a reactor, but concomitantly there exist remedies to ameliorate their impact. Obviously some price has to be paid in terms of reduced performance but lacking of materials or concepts which could substitute high-Z PFCs, emphasis has to be put on the development and optimization of reactor-relevant scenarios which incorporate the experiences and measures.

  4. High-Z plasma facing components in fusion devices: boundary conditions and operational experiences

    International Nuclear Information System (INIS)

    Neu, R.

    2006-01-01

    In present day fusion devices optimization of the performance and experimental freedom motivates the use of low-Z plasma facing materials (PFMs). However, in a future fusion reactor, for economic reasons, a sufficient lifetime of the first wall components is essential. Additionally, tritium retention has to be small to meet safety requirements. Tungsten appears to be the most realistic material choice for reactor plasma facing components (PFCs) because it exhibits the lowest erosion. But besides this there are a lot of criteria which have to be fulfilled simultaneously in a reactor. Results from present day devices and from laboratory experiments confirm the advantages of high-Z PFMs but also point to operational restrictions, when using them as PFCs. These are associated with the central impurity concentration, which is determined by the sputtering yield, the penetration of the impurities and their transport within the confined plasma. The restrictions could exclude successful operation of a reactor, but concomitantly there exist remedies to ameliorate their impact. Obviously some price has to be paid in terms of reduced performance but lacking of materials or concepts which could substitute high-Z PFCs, emphasis has to be put on the development and optimization of reactor-relevant scenarios which incorporate the experiences and measures

  5. Application of SSNTDs for measurements of fusion reaction products in high-temperature plasma experiments

    Energy Technology Data Exchange (ETDEWEB)

    Malinowska, A., E-mail: a.malinowska@ipj.gov.p [Andrzej Soltan Institute for Nuclear Studies (IPJ), 05-400 Otwock-Swierk (Poland); Szydlowski, A.; Malinowski, K. [Andrzej Soltan Institute for Nuclear Studies (IPJ), 05-400 Otwock-Swierk (Poland); Sadowski, M.J. [Andrzej Soltan Institute for Nuclear Studies (IPJ), 05-400 Otwock-Swierk (Poland); Institute of Plasma Physics and Laser Microfusion (IPPLM), 00-908 Warsaw (Poland); Zebrowski, J. [Andrzej Soltan Institute for Nuclear Studies (IPJ), 05-400 Otwock-Swierk (Poland); Scholz, M.; Paduch, M.; Zielinska, E. [Institute of Plasma Physics and Laser Microfusion (IPPLM), 00-908 Warsaw (Poland); Jaskola, M.; Korman, A. [Andrzej Soltan Institute for Nuclear Studies (IPJ), 05-400 Otwock-Swierk (Poland)

    2009-10-15

    The paper describes the application of SSNTDs of the PM-355 type to diagnostics of reaction products emitted from high-temperature deuterium plasmas produced in Plasma Focus (PF) facilities. Acceleration processes occurring in plasma lead often to the generation of high-energy ion beams. Such beams induce nuclear reactions and contribute to the emission of fast neutrons, fusion protons and alpha particles from PF discharges with a deuterium gas. Ion measurements are of primary importance for understanding the mechanisms of the physical processes which drive the charged-particle acceleration. The main aim of the present studies was to perform measurements of spatial- and energy-distributions of fusion-reaction protons (about 3 MeV) within a PF facility. Results obtained from energy measurements were compared with the proton-energy spectra computed theoretically. The protons were measured by means of a set of ion pinhole cameras equipped with PM-355 detectors, which were placed at different angles relative to the electrode axis of the PF facility.

  6. Roles of plasma neutron source reactor in development of fusion reactor engineering: Comparison with fission reactor engineering

    International Nuclear Information System (INIS)

    Hirayama, Shoichi; Kawabe, Takaya

    1995-01-01

    The history of development of fusion power reactor has come to a turning point, where the main research target is now shifting from the plasma heating and confinement physics toward the burning plasma physics and reactor engineering. Although the development of fusion reactor system is the first time for human beings, engineers have experience of development of fission power reactor. The common feature between them is that both are plants used for the generation of nuclear reactions for the production of energy, nucleon, and radiation on an industrial scale. By studying the history of the development of the fission reactor, one can find the existence of experimental neutron reactors including irradiation facilities for fission reactor materials. These research neutron reactors played very important roles in the development of fission power reactors. When one considers the strategy of development of fusion power reactors from the points of fusion reactor engineering, one finds that the fusion neutron source corresponds to the neutron reactor in fission reactor development. In this paper, the authors discuss the roles of the plasma-based neutron source reactors in the development of fusion reactor engineering, by comparing it with the neutron reactors in the history of fission power development, and make proposals for the strategy of the fusion reactor development. 21 refs., 6 figs

  7. Kinetic transport in a magnetically confined and flux-constrained fusion plasma; Transport cinetique dans un plasma de fusion magnetique a flux force

    Energy Technology Data Exchange (ETDEWEB)

    Darmet, G

    2007-11-15

    This work deals with the kinetic transport in a fusion plasma magnetically confined and flux-constrained. The author proposes a new interpretation of the dynamics of zonal flows. The model that has been studied is a gyrokinetic model reduced to the transport of trapped ions. The inter-change stability that is generated allows the study of the kinetic transport of trapped ions. This model has a threshold instability and can be simulated over a few tens confining time for either thermal bath constraint or flux constraint. For thermal baths constraint, the simulation shows a metastable state where zonal flows are prevailing while turbulence is non-existent. In the case of a flux-constraint, zonal flows appear and relax by exchanging energy with system's kinetic energy and turbulence energy. The competition between zonal flows and turbulence can be then simulated by a predator-prey model. 2 regimes can be featured out: an improved confining regime where zonal flows dominate transport and a turbulent regime where zonal flows and turbulent transport are of the same magnitude order. We show that flux as well as the Reynolds tensor play an important role in the dynamics of the zonal flows and that the gyrokinetic description is relevant for all plasma regions. (A.C.)

  8. EDITORIAL: The interaction of radio-frequency fields with fusion plasmas: the JET experience The interaction of radio-frequency fields with fusion plasmas: the JET experience

    Science.gov (United States)

    Ongena, Jef

    2012-07-01

    The JET Task Force Heating is proud to present this special issue. It is the result of hard and dedicated work by everybody participating in the Task Force over the last four years and gives an overview of the experimental and theoretical results obtained in the period 2008-2010 with radio frequency heating of JET fusion plasmas. Topics studied and reported in this issue are: investigations into the operation of lower hybrid heating accompanied by new modeling results; new experimental results and insights into the physics of various ion cyclotron range of frequencies (ICRF) heating scenarios; progress in studies of intrinsic and ion cyclotron wave-induced plasma rotation and flows; a summary of the developments over the last years in designing an ion cyclotron radiofrequency heating (ICRH) system that can cope with the presence of fast load variations in the edge, as e.g. caused by pellets or edge localized modes (ELMs) during H-Mode operation; an overview of the results obtained with the ITER-like antenna operating in H-Mode with a packed array of straps and power densities close to those of the projected ITER ICRH antenna; and, finally, a summary of the results obtained in applying ion cyclotron waves for wall conditioning of the tokamak. This issue would not have been possible without the strong motivation and efforts (sometimes truly heroic) of all colleagues of the JET Task Force Heating. A sincere word of thanks, therefore, to all authors and co-authors involved in the experiments, analysis and compilation of the papers. It was a special privilege to work with all of them during the past very intense years. Thanks also to all other European and non-European scientists who contributed to the JET scientific programme, the operations team of JET and the colleagues of the Close Support Unit in Culham. Thanks also to the editors, Editorial Board and referees of Plasma Physics and Controlled Fusion, together with the publishing staff of IOPP, who have not only

  9. On the economics of fusion breeders

    International Nuclear Information System (INIS)

    Greenspan, E.

    1984-01-01

    The potential for improving the economics of tandem mirror fusion breeders by assisting them with tritium produced in the control of the client light water reactors and/or by operating them with polarized plasma is assessed. Also assessed is the promise of a Starfire tokamak and a compact reversed field pinch fusion driver for fusion breeder applications. All three approaches are found to promise a significant reduction in the cost of fusion breeder produced fissile fuel, potentially making the FB-LWR system economically competitive with conventional nuclear energy systems. (orig.) [de

  10. Kinetic advantage of controlled intermediate nuclear fusion

    International Nuclear Information System (INIS)

    Guo Xiaoming

    2012-01-01

    The dominated process of controlled fusion is to let nuclei gain enough kinetic energy to overcome Coulomb barrier. As a result, a fusion scheme can consider two factors in its design: to increase kinetic energy of nuclei and to alter the Coulomb barrier. Cold Fusion and Hot fusion are all one-factor schemes while Intermediate Fusion is a twofactors scheme. This made CINF kinetically superior. Cold Fusion reduces deuteron-deuteron distance, addressing Coulomb barrier, and Hot Fusion heat up plasma into extreme high temperature, addressing kinetic energy. Without enough kinetic energy made Cold Fusion skeptical. Extreme high temperature made Hot Fusion very difficult to engineer. Because CIFN addresses both factors, CIFN is a more promising technique to be industrialized.

  11. Plasma Equilibrium Control in Nuclear Fusion Devices 2. Plasma Control in Magnetic Confinement Devices 2.1 Plasma Control in Tokamaks

    Science.gov (United States)

    Fukuda, Takeshi

    The plasma control technique for use in large tokamak devices has made great developmental strides in the last decade, concomitantly with progress in the understanding of tokamak physics and in part facilitated by the substantial advancement in the computing environment. Equilibrium control procedures have thereby been established, and it has been pervasively recognized in recent years that the real-time feedback control of physical quantities is indispensable for the improvement and sustainment of plasma performance in a quasi-steady-state. Further development is presently undertaken to realize the “advanced plasma control” concept, where integrated fusion performance is achieved by the simultaneous feedback control of multiple physical quantities, combined with equilibrium control.

  12. Development and Testing of Atomic Beam-Based Plasma Edge Diagnostics in the CIEMAT Fusion Devices

    International Nuclear Information System (INIS)

    Tafalla, D.; Tabares, F.L.; Ortiz, P.; Herrero, V.J.; Tanarro, I.

    1998-01-01

    In this report the development of plasma edge diagnostic based on atomic beam techniques fir their application in the CIEMAT fusion devices is described. The characterisation of the beams in laboratory experiments at the CSIC, together with first results in the Torsatron TJ-II are reported. Two types of beam diagnostics have been developed: a thermal (effusive) Li and a supersonic, pulsed He beams. This work has been carried out in collaboration between the institutions mentioned above under partial financial support by EURATOM. (Author) 17 refs

  13. Vacuum laser-produced plasma for analytical application in fusion technologies

    International Nuclear Information System (INIS)

    Almaviva, S; Caneve, L; Colao, F; Fantoni, R; Maddaluno, G

    2012-01-01

    LIBS is a well established tool for qualitative, semi-quantitative and quantitative analysis of surfaces, with micro-destructive characteristics and some capabilities for stratigraphy. In this work, the depth profiling capabilities of LIBS has been checked by determining the composition of multilayered samples simulating the plasma facing components fusion device covered with co-deposited impurity layers. A new experimental setup has been designed and realized in order to optimize the characteristics of a LIBS system working at low pressure and remotely.

  14. Feasibility study of direct spectra measurements for Thomson scattered signals for KSTAR fusion-grade plasmas

    Science.gov (United States)

    Park, K.-R.; Kim, K.-h.; Kwak, S.; Svensson, J.; Lee, J.; Ghim, Y.-c.

    2017-11-01

    Feasibility study of direct spectra measurements of Thomson scattered photons for fusion-grade plasmas is performed based on a forward model of the KSTAR Thomson scattering system. Expected spectra in the forward model are calculated based on Selden function including the relativistic polarization correction. Noise in the signal is modeled with photon noise and Gaussian electrical noise. Electron temperature and density are inferred using Bayesian probability theory. Based on bias error, full width at half maximum and entropy of posterior distributions, spectral measurements are found to be feasible. Comparisons between spectrometer-based and polychromator-based Thomson scattering systems are performed with varying quantum efficiency and electrical noise levels.

  15. Physics of laser-plasma interaction for shock ignition of fusion reactions

    International Nuclear Information System (INIS)

    Tikhonchuk, V T; Colaïtis, A; Vallet, A; Llor Aisa, E; Duchateau, G; Nicolaï, Ph; Ribeyre, X

    2016-01-01

    The shock ignition scheme is an alternative approach, which aims to achieve ignition of fusion reactions in two subsequent steps: first, the target is compressed at a low implosion velocity and second, a strong converging shock is launched during the stagnation phase and ignites the hot spot. In this paper we describe the major elements of this scheme and recent achievements concerning the laser-plasma interaction, the crucial role of hot electrons in the shock generation, the shock amplification in the imploding shell and the ignition conditions. (paper)

  16. The measurement of potential distribution of plasma in MM-4 fusion device

    International Nuclear Information System (INIS)

    Tian Zhongyu; Ming Linzhou; Feng Xiaozhen; Feng Chuntang; Yi Youjun; Wang Jihai; Liu Yihua

    1988-11-01

    Some experimental results of the potential distribution in MM-4 fusion device are presented by measuring the floating potential of probe. The results showed that the distribution of axial potential is asymmetrical, but the radial potential is symmetrical. There are double ion potential wells in the plasma. The depth of the deepest potential well become deeper is the strength of the magnetic field and injection current are increasing. The location of the deepest well is moved towards the device center along with the increasing of injection energy. This is different from others results. The mechanism of causing this distribution in also discussed

  17. Multiple-beam laser–plasma interactions in inertial confinement fusion

    Energy Technology Data Exchange (ETDEWEB)

    Myatt, J. F., E-mail: jmya@lle.rochester.edu; Zhang, J.; Maximov, A. V. [Laboratory for Laser Energetics, University of Rochester, 250 East River Road, Rochester, New York 14623-1299 (United States); Department of Mechanical Engineering, University of Rochester, Rochester, New York 14627 (United States); Short, R. W.; Seka, W.; Edgell, D. H.; Michel, D. T.; Igumenshchev, I. V. [Laboratory for Laser Energetics, University of Rochester, 250 East River Road, Rochester, New York 14623-1299 (United States); Froula, D. H. [Laboratory for Laser Energetics, University of Rochester, 250 East River Road, Rochester, New York 14623-1299 (United States); Department of Physics and Astronomy, University of Rochester, Rochester, New York 14627-0171 (United States); Hinkel, D. E.; Michel, P.; Moody, J. D. [Lawrence Livermore National Laboratory, P.O. Box 808, Livermore, California 94551-0808 (United States)

    2014-05-15

    The experimental evidence for multiple-beam laser-plasma instabilities of relevance to laser driven inertial confinement fusion at the ignition scale is reviewed, in both the indirect and direct-drive approaches. The instabilities described are cross-beam energy transfer (in both indirectly driven targets on the NIF and in direct-drive targets), multiple-beam stimulated Raman scattering (for indirect-drive), and multiple-beam two-plasmon decay instability (in direct drive). Advances in theoretical understanding and in the numerical modeling of these multiple beam instabilities are presented.

  18. IEFIT - An Interactive Approach to High Temperature Fusion Plasma Magnetic Equilibrium Fitting

    International Nuclear Information System (INIS)

    Peng, Q.; Schachter, J.; Schissel, D.P.; Lao, L.L.

    1999-01-01

    An interactive IDL based wrapper, IEFIT, has been created for the magnetic equilibrium reconstruction code EFIT written in FORTRAN. It allows high temperature fusion physicists to rapidly optimize a plasma equilibrium reconstruction by eliminating the unnecessarily repeated initialization in the conventional approach along with the immediate display of the fitting results of each input variation. It uses a new IDL based graphics package, GaPlotObj, developed in cooperation with Fanning Software Consulting, that provides a unified interface with great flexibility in presenting and analyzing scientific data. The overall interactivity reduces the process to minutes from the usual hours

  19. Apparatus and method for removing particle species from fusion-plasma-confinement devices

    Science.gov (United States)

    Hamilton, G.W.

    1981-10-26

    In a mirror fusion plasma confinement apparatus, method and apparatus are provided for selectively removing (pumping) trapped low energy (thermal) particle species from the end cell region, without removing the still useful high energy particle species, and without requiring large power input to accomplish the pumping. Perturbation magnets are placed in the thermal barrier region of the end cell region at the turning point characteristic of trapped thermal particles, thus deflecting the thermal particles from their closed trajectory, causing them to drift sufficiently to exit the thermal barrier.

  20. ASDEX contributions to the 17th European conference on controlled fusion and plasma heating

    International Nuclear Information System (INIS)

    1990-09-01

    The 'ASDEX contributions to the 17th European conference on controlled fusion and plasma heating' (Amsterdam, June 25-29, 1990) hold one invited paper (Physics of enhanced confinement with peaked and board density profiles) and 12 chapters containing 44 contributed papers dealing with the following topics: Lower hybrid current drive and heating; Ion cyclotron heating; General confinement studies; Fluctuation studies; Direct measurement of transport coefficients; H-mode studies; Pellet studies; Divertor and SOL-studies; Impurity and impurity transport studies; Density limit studies; MHD studies; Diagnostic development. (orig./AH)

  1. On fractal properties of equipotentials over a real rough surface faced to plasma in fusion devices

    International Nuclear Information System (INIS)

    Budaev, V.P.; Yakovlev, M.

    2008-01-01

    We consider a sheath region bounded by a corrugated surface of material conductor and a flat boundary held to a constant voltage bias. The real profile of the film deposited from plasma on a limiter in a fusion device was used in numerical solving of the Poisson's equation to find a profile of electrostatic potential. The rough surface influences the equipotential lines over the surface. We characterized a shape of equipotential lines by a fractal dimension. The long-range correlation in the potential field is imposed by the non-trivial fractal structure of the surface. Dust particles bounced in such irregular potential field can accelerate due to the Fermi acceleration. (author)

  2. Plasma viscosity with mass transport in spherical inertial confinement fusion implosion simulations

    Energy Technology Data Exchange (ETDEWEB)

    Vold, E. L.; Molvig, K. [Los Alamos National Laboratory, Los Alamos, New Mexico 87545 (United States); Joglekar, A. S. [University of Michigan, Ann Arbor, Michigan 48109 (United States); Ortega, M. I. [University of New Mexico, Albuquerque, New Mexico 87131 (United States); Moll, R. [University of California, Santa Cruz, California 95064 (United States); Fenn, D. [Florida State University, Tallahassee, Florida 32306 (United States)

    2015-11-15

    The effects of viscosity and small-scale atomic-level mixing on plasmas in inertial confinement fusion (ICF) currently represent challenges in ICF research. Many current ICF hydrodynamic codes ignore the effects of viscosity though recent research indicates viscosity and mixing by classical transport processes may have a substantial impact on implosion dynamics. We have implemented a Lagrangian hydrodynamic code in one-dimensional spherical geometry with plasma viscosity and mass transport and including a three temperature model for ions, electrons, and radiation treated in a gray radiation diffusion approximation. The code is used to study ICF implosion differences with and without plasma viscosity and to determine the impacts of viscosity on temperature histories and neutron yield. It was found that plasma viscosity has substantial impacts on ICF shock dynamics characterized by shock burn timing, maximum burn temperatures, convergence ratio, and time history of neutron production rates. Plasma viscosity reduces the need for artificial viscosity to maintain numerical stability in the Lagrangian formulation and also modifies the flux-limiting needed for electron thermal conduction.

  3. EURATOM-CEA Association Contributions to the 16. European Conference on Controlled Fusion and Plasma Physics

    International Nuclear Information System (INIS)

    1989-01-01

    The contributions to the 16th European Conference on controlled fusion and Plasma Physics are presented. The following subjects, concerning Tore Supra, are discussed: runaway electrons dynamics and confinement; spectroscopic studies of plasma surface interactions; ergodic divertor experiments; magnetic field structure and transport induced by the ergodic divertor; fast ions losses during neutral beam injection; current profile control by electron-cyclotron and lower-hybrid waves; and electromagnetic analysis of the lower hybrid system. The report also includes studies on: a possible explanation for the runaway energy limit (resonant interaction with the ripple field); thermal equilibrium of the edge plasma with an ergodic divertor; neutral confinement in pump limiter with a throat; microtearing turbulence and heat transport; toroidal coupling and frequency spectrum of tearing modes; collisionless fast ion dynamics in tokamaks; variational description of lower hybrid wave propagation and absorption in tokamaks; magnetodrift turbulence and disruptions; specific turbulence associated with sawtooth relaxations in TFR plasmas; detailed structure of the q profile around q = 1 in JET; turbulence propagation during pellet injection; tokamak reactor concept with 100% bootstrap current; optimization of a steady state tokamak driven by lower hybrid waves; and thermodesorption of graphite exposed to a deuterium plasma

  4. Classical Methods of Statistics With Applications in Fusion-Oriented Plasma Physics

    CERN Document Server

    Kardaun, Otto J W F

    2005-01-01

    Classical Methods of Statistics is a blend of theory and practical statistical methods written for graduate students and researchers interested in applications to plasma physics and its experimental aspects. It can also fruitfully be used by students majoring in probability theory and statistics. In the first part, the mathematical framework and some of the history of the subject are described. Many exercises help readers to understand the underlying concepts. In the second part, two case studies are presented exemplifying discriminant analysis and multivariate profile analysis. The introductions of these case studies outline contextual magnetic plasma fusion research. In the third part, an overview of statistical software is given and, in particular, SAS and S-PLUS are discussed. In the last chapter, several datasets with guided exercises, predominantly from the ASDEX Upgrade tokamak, are included and their physical background is concisely described. The book concludes with a list of essential keyword transl...

  5. Fusion Plasma Theory Grant: Task 3, Auxiliary Radiofrequency Heating of Tokamaks

    International Nuclear Information System (INIS)

    Scharer, J.E.

    1993-06-01

    The research performed under this grant during the past year has been concentrated on the following several key tokamak ICRF (Ion Cyclotron Range of Frequencies) coupling, heating and current drive issues. We have made progress in developing a ''3-D'' cavity backed antenna array code to examine ICRF coupling to general plasma edge profiles. The effects of the finite antenna length and feeders as well as Faraday shield blade angle are being examined. We are also developing an analysis to examine large k perpendicular ρ gyroradius interaction between alpha or beam particles and ICRF waves. This topic has important applications in the areas of ICRF heating for deuterium-tritium fusion plasmas, TAE modes, ash removal and minority ion current drive. Research progress, publications, and conference and workshop presentations are summarized in this report

  6. The structure, properties and performance of plasma-sprayed beryllium for fusion applications

    International Nuclear Information System (INIS)

    Castro, R.G.; Stanek, P.W.; Elliott, K.E.

    1995-01-01

    Plasma-spray technology is under investigation as a method for producing high thermal conductivity beryllium coatings for use in magnetic fusion applications. Recent investigations have focused on optimizing the plasma-spray process for depositing beryllium coatings on damaged beryllium surfaces. Of particular interest has been optimizing the processing parameters to maximize the through-thickness thermal conductivity of the beryllium coatings. Experimental results will be reported on the use of secondary H 2 gas additions to improve the melting of the beryllium powder and transferred-arc cleaning to improve the bonding between the beryllium coatings and the underlying surface. Information will also be presented on thermal fatigue tests which were done on beryllium coated ISX-B beryllium limiter tiles using 10 sec cycle times with 60 sec cooldowns and an International Thermonuclear Experimental Reactor (ITER) relevant divertor heat flux slightly in excess of 5 MW/m 2

  7. A statistical approach for predicting thermal diffusivity profiles in fusion plasmas as a transport model

    International Nuclear Information System (INIS)

    Yokoyama, Masayuki

    2014-01-01

    A statistical approach is proposed to predict thermal diffusivity profiles as a transport “model” in fusion plasmas. It can provide regression expressions for the ion and electron heat diffusivities (χ i and χ e ), separately, to construct their radial profiles. An approach that this letter is proposing outstrips the conventional scaling laws for the global confinement time (τ E ) since it also deals with profiles (temperature, density, heating depositions etc.). This approach has become possible with the analysis database accumulated by the extensive application of the integrated transport analysis suite to experiment data. In this letter, TASK3D-a analysis database for high-ion-temperature (high-T i ) plasmas in the LHD (Large Helical Device) is used as an example to describe an approach. (author)

  8. Analysis of the accident with the coolant discharge into the plasma vessel of the W7-X fusion experimental facility

    Energy Technology Data Exchange (ETDEWEB)

    Ušpuras, E.; Kaliatka, A.; Kaliatka, T., E-mail: tadas@mail.lei.lt

    2013-06-15

    Highlights: • The accident with water ingress into the plasma vessel in Wendelstein nuclear fusion device W7-X was analyzed. • The analysis of the processes in the plasma vessel and ventilation system was performed using thermal-hydraulic RELAP5 Mod3.3 code. • The suitability of pressure increase prevention system was assessed. • All analyses results will be used for the optimization of W7-X design and to ensure safe operation of this nuclear fusion device. -- Abstract: Fusion is the energy production technology, which could potentially solve problems with growing energy demand of population in the future. Starting 2007, Lithuanian Energy Institute (LEI) is a member of European Fusion Development Agreement (EFDA) organization. LEI is cooperating with Max Planck Institute for Plasma Physics (IPP, Germany) in the frames of EFDA project by performing safety analysis of fusion device W7-X. Wendelstein 7-X (W7-X) is an experimental stellarator facility currently being built in Greifswald, Germany, which shall demonstrate that in the future energy could be produced in such type of fusion reactors. In this paper the safety analysis of 40 mm inner diameter coolant pipe rupture in cooling circuit and discharge of steam–water mixture through the leak into plasma vessel during the W7-X no-plasma “baking” operation mode is presented. For the analysis the model of W7-X cooling system (pumps, valves, pipes, hydro-accumulators, and heat exchangers) and plasma vessel was developed by employing system thermal-hydraulic state-of-the-art RELAP5 Mod3.3 code. This paper demonstrated that the developed RELAP5 model enables to analyze the processes in divertor cooling system and plasma vessel. The results of analysis demonstrated that the proposed burst disc, connecting the plasma vessel with venting system, opens and pressure inside plasma vessel does not exceed the limiting 1.1 × 10{sup 5} Pa absolute pressure. Thus, the plasma vessel remains intact after loss

  9. Preparing Platelet-Rich Plasma with Whole Blood Harvested Intraoperatively During Spinal Fusion.

    Science.gov (United States)

    Shen, Bin; Zhang, Zheng; Zhou, Ning-Feng; Huang, Yu-Feng; Bao, Yu-Jie; Wu, De-Sheng; Zhang, Ya-Dong

    2017-07-22

    BACKGROUND Platelet-rich plasma (PRP) has gained growing popularity in use in spinal fusion procedures in the last decade. Substantial intraoperative blood loss is frequently accompanied with spinal fusion, and it is unknown whether blood harvested intraoperatively qualifies for PRP preparation. MATERIAL AND METHODS Whole blood was harvested intraoperatively and venous blood was collected by venipuncture. Then, we investigated the platelet concentrations in whole blood and PRP, the concentration of growth factors in PRP, and the effects of PRP on the proliferation and viability of human bone marrow-derived mesenchymal stem cells (HBMSCs). RESULTS Our results revealed that intraoperatively harvested whole blood and whole blood collected by venipuncture were similar in platelet concentration. In addition, PRP formulations prepared from both kinds of whole blood were similar in concentration of platelet and growth factors. Additional analysis showed that the similar concentrations of growth factors resulted from the similar platelet concentrations of whole blood and PRP between the two groups. Moreover, these two kinds of PRP formulations had similar effects on promoting cell proliferation and enhancing cell viability. CONCLUSIONS Therefore, intraoperatively harvested whole blood may be a potential option for preparing PRP spinal fusion.

  10. Integrated Approach to Dense Magnetized Plasmas Applications in Nuclear Fusion Technology. Report of a Coordinated Research Project 2007-2011

    International Nuclear Information System (INIS)

    2013-04-01

    Through its coordinated research activities, the IAEA promotes the development and application of nuclear technologies in Member States. The scientific and technical knowledge required for the construction and operation of large nuclear fusion research facilities, including ITER and the Laser Megajoule in France, and the Z machine and the National Ignition Facility in the United States of America, necessitates several accompanying research and development programmes in physics and technology. This is particularly true in the areas of materials science and fusion technology. Hence, the long standing IAEA effort to conduct coordinated research projects (CRPs) in these areas is aimed at: (i) the development of appropriate technical tools to investigate the issue of materials damage and degradation in a fusion plasma environment; and (ii) the emergence of a knowledge based understanding of the various processes underlying materials damage and degradation, thereby leading to the identification of suitable candidate materials fulfilling the stringent requirements of a fusion environment in any next step facility. Dense magnetized plasma (DMP) devices serve as a first test bench for testing of fusion relevant plasma facing materials, diagnostic development and calibration, technologies and scaling to conceptual principles of larger devices while sophisticated testing facilities such as the International Fusion Materials Irradiation Facility (IFMIF) are being designed. The CRP on Integrated Approach to Dense Magnetized Plasmas Applications in Nuclear Fusion Technology described herein was initiated in 2007 with the participation of 12 research institutions in 8 Member States and was concluded in 2011. It was designed with specific research objectives falling into two main categories: support to mainstream fusion research and development of DMP technology. This publication is a compilation of the individual reports submitted by the 12 CRP participants. These reports discuss

  11. Dust in fusion devices-a multi-faceted problem connecting high- and low-temperature plasma physics

    International Nuclear Information System (INIS)

    Winter, J

    2004-01-01

    Small particles with sizes between a few nanometers and a few 10 μm (dust) are formed in fusion devices by plasma-surface interaction processes. Though it is not a major problem today, dust is considered a problem that could arise in future long pulse fusion devices. This is primarily due to its radioactivity and due to its very high chemical reactivity. Dust formation is particularly pronounced when carbonaceous wall materials are used. Dust particles can be transported in the tokamak over significant distances. Radioactivity leads to electrical charging of dust and to its interaction with plasmas and electric fields. This may cause interference with the discharge but may also result in options for particle removal. This paper discusses some of the multi-faceted problems using information both from fusion research and from low-temperature dusty plasma work

  12. Reduction of metal oxides in metal carbide fusion superheated with plasma

    Energy Technology Data Exchange (ETDEWEB)

    Hedai, L

    1981-01-01

    A significant part of metals is capable of binding a high quantity of carbon in the form of carbide. The carbide fusion produced as a result of smelting and superheating, metal carbides with the use of plasma might be a medium to be utilized for the reduction of different metal oxides, whilst also the original carbide structure of the metal carbides will be reduced to metallic structure. The experiments conducted by making use of plasma equipment, of 20, 55 and 100 kW performances are described. On the basis of the results of the experiments performed, the following statements are to be made. The oxide reductions taking place in the metal carbide fusion might also be carried out in open-hearth furnaces, because reducing atmosphere is not necessitated during this procedure. The quantity of energy required is basically defined by the energy needed for smelting and superheating the metal carbide. The method for producing the metal described may be mainly applied for the allied production of high-purity steels as well as for that of ferro-alloys.

  13. Noise temperature improvement for magnetic fusion plasma millimeter wave imaging systems

    Energy Technology Data Exchange (ETDEWEB)

    Lai, J.; Domier, C. W.; Luhmann, N. C. [Department of Electrical and Computer Engineering, University of California at Davis, Davis, California 95616 (United States)

    2014-03-15

    Significant progress has been made in the imaging and visualization of magnetohydrodynamic and microturbulence phenomena in magnetic fusion plasmas [B. Tobias et al., Plasma Fusion Res. 6, 2106042 (2011)]. Of particular importance have been microwave electron cyclotron emission imaging and microwave imaging reflectometry systems for imaging T{sub e} and n{sub e} fluctuations. These instruments have employed heterodyne receiver arrays with Schottky diode mixer elements directly connected to individual antennas. Consequently, the noise temperature has been strongly determined by the conversion loss with typical noise temperatures of ∼60 000 K. However, this can be significantly improved by making use of recent advances in Monolithic Microwave Integrated Circuit chip low noise amplifiers to insert a pre-amplifier in front of the Schottky diode mixer element. In a proof-of-principle design at V-Band (50–75 GHz), significant improvement of noise temperature from the current 60 000 K to measured 4000 K has been obtained.

  14. Interfacial Stability of Spherically Converging Plasma Jets for Magnetized Target Fusion

    Science.gov (United States)

    Thio, Y. C. Francis; Cassibry, Jason; Wu, S. T.; Eskridge, Richard; Smith, James; Lee, Michael; Rodgers, Stephen L. (Technical Monitor)

    2000-01-01

    A fusion propulsion scheme has been proposed that makes use of the merging of a spherical distribution of plasma jets to dynamically form a gaseous liner to implode a magnetized target to produce the fusion reaction. In this paper, a study is made of the interfacial stability of the interaction of these jets. Specifically, the Orr-Sommerfeld equation is integrated to obtain the growth rate of a perturbation to the primary flow at the interface between the colliding jets. The results lead to an estimate on the tolerances on the relative flow velocities of the merging plasma jets to form a stable, imploding liner. The results show that the maximum temporal growth rate of the perturbed flow at the jet interface is very small in comparison with the time to full compression of the liner. These data suggest that, as far as the stability of the interface between the merging jets is concerned, the formation of the gaseous liner can withstand velocity variation of the order of 10% between the neighboring jets over the density and temperature ranges investigated.

  15. Variance-reduction technique for Coulomb-nuclear thermalization of energetic fusion products in hot plasmas

    International Nuclear Information System (INIS)

    DeVeaux, J.C.; Miley, G.H.

    1982-01-01

    A variance-reduction technique involving use of exponential transform and angular-biasing methods has been developed. Its purpose is to minimize the variance and computer time involved in estimating the mean fusion product (fp) energy deposited in a hot, multi-region plasma under the influence of small-energy transfer Coulomb collisions and large-energy transfer nuclear elastic scattering (NES) events. This technique is applicable to high-temperature D- 3 He, Cat. D and D-T plasmas which have highly energetic fps capable of undergoing NES. A first application of this technique is made to a D- 3 He Field Reversed Mirror (FRM) where the Larmor radius of the 14.7 MeV protons are typically comparable to the plasma radius (plasma radius approx. 2 fp gyroradii) and the optimistic fp confinement (approx. 45% of 14.7 MeV protons) previously predicted is vulnerable to large orbit perturbations induced by NES. In the FRM problem, this variance reduction technique is used to estimate the fractional difference in the average fp energy deposited in the closed-field region, E/sub cf/, with and without NES collisions

  16. First observation of the depolarization of Thomson scattering radiation by a fusion plasma

    Science.gov (United States)

    Giudicotti, L.; Kempenaars, M.; McCormack, O.; Flanagan, J.; Pasqualotto, R.; contributors, JET

    2018-04-01

    We report the first experimental observation of the depolarization of the Thomson scattering (TS) radiation, a relativistic effect expected to occur in very high {{T}e} plasmas and never observed so far in a fusion machine. A set of unused optical fibers in the collection optics of the high resolution Thomson scattering system of JET has been used to detect the depolarized TS radiation during a JET campaign with {{T}e}≤slant 8 keV . A linear polarizer with the axis perpendicular to the direction of the incident E-field was placed in front of a fiber optic pair observing a region close to the plasma core, while another fiber pair with no polariser simultaneously observed an adjacent plasma region. The measured intensity ratio was found to be consistent with the theory, taking into account sensitivity coefficients of the two measurement channels determined with post-experiment calibrations and Raman scattering. This depolarization effect is at the basis of polarimetric TS, a different and complementary method for the analysis of TS spectra that can provide significant advantages for {{T}e} measurements in very hot plasmas such as in ITER ≤ft({{T}e}≤slant 40 keV \\right) .

  17. IGNITOR, ITER and NIF in the Context of the World Effort on Fusion Burning Plasmas

    Science.gov (United States)

    Azizov, E.; Coppi, B.; Velikhov, E.

    2012-03-01

    As of last summer, the ITER program has been recognized as being directed at providing an ``International Platform for Fusion Technology.'' Then, the two experimental programs that have the explicit goal to approach ignition conditions with D-T plasmas are NIF and IGNITOR. NIF, the National Ignition Facility, is based on the inertial confinement principle using a laser system capable of delivering 1.6 MJ and is being operated in Livermore. IGNITOR will be operated by the Kurchatov Institute within the research center of Troitzk presently owned by Rosatom and involves a high level collaboration between Italy and Russia. For this, Ignitor has been defined as a Flagship Project by Italy and the construction of its core has been funded. The Ignitor design is based on the experimental results obtained by the high field line of experiments carried out at MIT, within the Alcator Program, and in Italy within the Frascati Torus Program. A wide set of experiments in Japan, on high density plasmas, in the US, Russia and Europe have produced plasma physics results and technology developments that have guided the evolution of the Ignitor design. The main theoretical plasma physics issues to be dealt with in connection with this program are discussed.

  18. Incompressible LFR MHD. A fluid model for stability analysis of a fusion plasma

    International Nuclear Information System (INIS)

    Scheffel, J.; Faghihi, M.

    1986-10-01

    A fluid model including FLR effects, named Incompressible Finite Larmor Radius MagnetoHydroDynamics, is presented and derived in this paper. It is an extension of ordinary, incompressible MHD to include the Larmor radius effects due to ion gyroviscosity, Hall current and electron diamagnetism. It is intended to use the model for stability analysis, on the Alfven wave time scale, of a fusion plasma and it is consequently based on transport coefficients in the collisionless limit. It will be demonstrated that for a fairly dense and cool plasma, such as for the EXTRAP z-pinch, all three Larmor radius effects may become important, that for a JET-type plasma no FLR effect is pronounced, and that in a reactor plasma the Hall and electron diamagnetism term may play a role. For scaling lengths signigicantly smaller than the plasma radius the effect of the FLR terms becomes enhanced. To study the importance of the choice of equations of state for the model the m=1 and k 2 r 2 towards infinity instability in cylindrical geometry is given special attention for zero Larmor radius. The full stability criterion of the double adiabatic model, including pressure anisotropy, is presented for what we believe to be the first time. It is found that when perpendicular p > parallel p stability can be reached for very high plasma perpendicular β-values. We demonstrate that no less complicated energy conserving fluid model, which takes into account pressure anisotropy, other than the double adiabativ model can be obtained. Since pressure anisotropy generally only weakly affects stability, we can assume isotropy in the Incompressible FLR MHD model. Also, the energy equation is replaced by the incompressibility condition, making FLR terms appearing in the energy equation irrelevant. (authors)

  19. Nuclear measurements, techniques and instrumentation, industrial applications, plasma physics and nuclear fusion 1986-1996. International Atomic Energy Agency publications

    International Nuclear Information System (INIS)

    1997-03-01

    This catalogue lists all sales publications of the International Atomic Energy Agency dealing with Nuclear Measurements, Techniques, and Instrumentation, Industrial Applications, Plasma Physics and Nuclear Fusion, issued during the period 1986-1996. Most publications are in English. Proceedings of conferences, symposia and panels of experts may contain some papers in languages other than English (French, Russian or Spanish), but all of these papers have abstracts in English. Contents cover the three main areas of (i) Nuclear Measurements, Techniques and Instrumentation (Physics, Dosimetry Techniques, Nuclear Analytical Techniques, Research Reactor and Particle Accelerator Applications, and Nuclear Data), (ii) Industrial Applications (Radiation Processing, Radiometry, and Tracers), and (iii) Plasma Physics and Controlled Thermonuclear Fusion

  20. Application of neural networks and its prospect. 1. General comment on application to nuclear fusion and plasma researches

    International Nuclear Information System (INIS)

    Takeda, Tatsuoki

    2006-01-01

    The back ground of application of neutral networks to R and D of scientific field and increasing of application fields are stated. A definition of neural networks, the kinds of neural networks and functions, error back propagation, and generalization are explained. An application of multi-layer neural networks to nuclear fusion and plasma researches are described by inverse problem, interpolation, time series prediction, and computerized tomography. Some examples of researches such as MHD of plasma from magnetic probe data of fusion reactor systems, parameter prediction of distribution of the impurity spectra and the charge exchange neutral particle energy spectra, disruption prediction, and residual minimization training neural network are commented. (S.Y.)

  1. Control of plasma layer in a fusion reactor correlated to DC motor control using PSO-ANFIS

    International Nuclear Information System (INIS)

    Mahapatra, Sakuntala; Daniel, Raju; Dey, Deep Narayan

    2013-01-01

    Plasma position and shape control is very crucial for the overall performance of the fusion reactor such as Tokamak. The quality of the discharge in the Saskatchewan TORus-Modified (STOR-M) tokamak is strongly related to the position of the plasma column within the discharge vessel. If the plasma column approaches too near the wall, then either minor or complete disruption occurs. Consequently it is necessary to be able to control dynamically the position of the plasma column throughout the entire discharge. Now a day's most fusion reactor employs the traditional PID controller for the confinement of plasma layer. Fuzzy logic is used for the control of Plasma layer. In this paper we have used the hybrid of PSO-ANFIS technique to control the speed of a DC motor. We have used two input parameters like speed, torque and output is firing angle. In our work first order Sugeno fuzzy model is taken with three rules and the parameters of Gaussian membership function is controlled by the PSO technique. PSO-ANFIS speed controller obtains better dynamic behavior and superior performance of the DC motor speed control. Similar approach can be correlated to the control of plasma layer. For the plasma control two inputs can be taken as plasma position ΔH and the plasma current and the single output, the control decision u(t). (author)

  2. The Penning fusion experiment-ions

    International Nuclear Information System (INIS)

    Schauer, M. M.; Umstadter, K. R.; Barnes, D. C.

    1999-01-01

    The Penning fusion experiment (PFX) studies the feasibility of using a Penning trap as a fusion confinement device. Such use would require spatial and/or temporal compression of the plasma to overcome the Brillouin density limit imposed by the nonneutrality of Penning trap plasmas. In an earlier experiment, we achieved enhanced plasma density at the center of a pure, electron plasma confined in a hyperbolic, Penning trap by inducing spherically convergent flow in a nonthermal plasma. The goal of this work is to induce similar flow in a positive ion plasma confined in the virtual cathode provided by a spherical, uniform density electron plasma. This approach promises the greatest flexibility in operating with multi-species plasmas (e.g. D + /T + ) or implementing temporal compression schemes such as the Periodically Oscillating Plasma Sphere of Nebel and Barnes. Here, we report on our work to produce and diagnose the necessary electron plasma

  3. Modelling of the edge of a fusion plasma towards ITER and experimental validation on JET

    International Nuclear Information System (INIS)

    Guillemaut, Christophe

    2013-01-01

    The conditions required for fusion can be obtained in tokamaks. In most of these machines, the plasma wall-interaction and the exhaust of heating power are handled in a cavity called divertor. However, the high heat flux involved and the limitations of the materials of the plasma facing components (PFC) are problematic. Many researches are done this field in the context of ITER which should demonstrate 500 MW of DT fusion power during ∼ 400 s. Such operations could bring the heat flux on the PFC too high to be handled. Its reduction to manageable levels relies on the divertor detachment involving the reduction of the particle and heat fluxes on the PFC. Unfortunately, this phenomenon is still difficult to model. The aim of this PhD is to use the modelling of JET experiments with EDGE2D-EIRENE to make some progress in the understanding of the detachment. The simulations reproduce the observed detachment in C and Be/W environments. The distribution of the radiation is well reproduced by the code for C but with some discrepancies in Be/W. The comparison between different sets of atomic physics processes shows that ion-molecule elastic collisions are responsible for the detachment seen in EDGE2D-EIRENE. This process provides good neutral confinement in the divertor and significant momentum losses at low temperature, when the plasma is recombining. Comparison between EDGE2D-EIRENE and SOLPS4.3 shows similar detachment trends but the importance of the ion-molecule elastic collisions is reduced in SOLPS4.3. Both codes suggest that any process capable of improving the neutral confinement in the divertor should help to improve the modelling of the detachment. (author) [fr

  4. Automatically Identifying Fusion Events between GLUT4 Storage Vesicles and the Plasma Membrane in TIRF Microscopy Image Sequences

    Directory of Open Access Journals (Sweden)

    Jian Wu

    2015-01-01

    Full Text Available Quantitative analysis of the dynamic behavior about membrane-bound secretory vesicles has proven to be important in biological research. This paper proposes a novel approach to automatically identify the elusive fusion events between VAMP2-pHluorin labeled GLUT4 storage vesicles (GSVs and the plasma membrane. The differentiation is implemented to detect the initiation of fusion events by modified forward subtraction of consecutive frames in the TIRFM image sequence. Spatially connected pixels in difference images brighter than a specified adaptive threshold are grouped into a distinct fusion spot. The vesicles are located at the intensity-weighted centroid of their fusion spots. To reveal the true in vivo nature of a fusion event, 2D Gaussian fitting for the fusion spot is used to derive the intensity-weighted centroid and the spot size during the fusion process. The fusion event and its termination can be determined according to the change of spot size. The method is evaluated on real experiment data with ground truth annotated by expert cell biologists. The evaluation results show that it can achieve relatively high accuracy comparing favorably to the manual analysis, yet at a small fraction of time.

  5. Antimicrobial Peptides Derived from Fusion Peptides of Influenza A Viruses, a Promising Approach to Designing Potent Antimicrobial Agents.

    Science.gov (United States)

    Wang, Jingyu; Zhong, Wenjing; Lin, Dongguo; Xia, Fan; Wu, Wenjiao; Zhang, Heyuan; Lv, Lin; Liu, Shuwen; He, Jian

    2015-10-01

    The emergence and dissemination of antibiotic-resistant bacterial pathogens have spurred the urgent need to develop novel antimicrobial agents with different mode of action. In this respect, we turned several fusogenic peptides (FPs) derived from the hemagglutinin glycoproteins (HAs) of IAV into potent antibacterials by replacing the negatively or neutrally charged residues of FPs with positively charged lysines. Their antibacterial activities were evaluated by testing the MICs against a panel of bacterial strains including S. aureus, S. mutans, P. aeruginosa, and E. coli. The results showed that peptides HA-FP-1, HA-FP-2-1, and HA-FP-3-1 were effective against both Gram-positive and Gram-negative bacteria with MICs ranging from 1.9 to 16.0 μm, while the toxicities toward mammalian cells were low. In addition, the mode of action and the secondary structure of these peptides were also discussed. These data not only provide several potent peptides displaying promising potential in development as broad antimicrobial agents, but also present a useful strategy in designing new antimicrobial agents. © 2015 John Wiley & Sons A/S.

  6. Transport in a fusion plasma in presence of a chaotic magnetic field

    International Nuclear Information System (INIS)

    Nguyen, F.

    1992-09-01

    In the tokamak Tore Supra, the magnetic field ensuring the confinement is stochastic at the plasma edge due to a resonant perturbation. This perturbation is created by a set of six helicoidal coils inside the vacuum vessel, the ergodic divertor. The first part of the study concerns the analysis of the transport of particles and energy in a fusion plasma in presence of a stochastic magnetic field, without physical wall. The effective transport of electrons, i.e. heat transport, increases. The ions transport increases too but less than heat transport. The discrepancy produces a mean radial electric field. The second part is devoted to the influence of the physical wall. The topology of the magnetic connexion on the wall is precisely determined with the code Mastoc. The transport of particles and energy is then described from the confined plasma until the wall. This study enlights severals important observations of the experience Tore Supra in the ergodic divertor configuration: the spreading of the power deposition on the wall components without anomalous concentration, the robustness of this configuration relatively to misalignment, the edge structures visible in H α light during plasma reattachment. In order to study the transport of impurity ions, a variational approach of minimum entropy production has been developped. This principle is applied to the calculation of the neoclassical diffusion of impurity ions with the radial electric field. This electric field deconfines ions if the pressure profile is not balanced by a Lorentz force, i.e. if the plasma is locked in rotation, poloidally and toroidally, because of magnetic perturbation or friction force

  7. Suppression of Stimulated Brillouin Scattering in multiple-ion species inertial confinement fusion Hohlraum Plasmas

    International Nuclear Information System (INIS)

    Neumayer, P

    2007-01-01

    A long-standing problem in the field of laser-plasma interactions is to successfully employ multiple-ion species plasmas to reduce stimulated Brillouin scattering (SBS) in inertial confinement fusion (ICF) hohlraum conditions. Multiple-ion species increase significantly the linear Landau damping for acoustic waves. Consequently, recent hohlraum designs for indirect-drive ignition on the National Ignition Facility investigate wall liner material options so that the liner gain for parametric instabilities will be below threshold for the onset SBS. Although the effect of two-ion species plasmas on Landau damping has been directly observed with Thomson scattering, early experiments on SBS in these plasmas have suffered from competing non-linear effects or laser beam filamentation. In this study, a reduction of SBS scattering to below the percent level has been observed in hohlraums at Omega that emulate the plasma conditions in an indirect drive ICF experiments. These experiments have measured the laser-plasma interaction processes in ignition-relevant high-electron temperature regime demonstrating Landau damping as a controlling process for SBS. The hohlraums have been filled with various fractions of CO 2 and C 3 H 8 varying the ratio of the light (H) to heavy (C and O) ion density from 0 to 2.6. They have been heated by 14.5 kJ of 351-nm light, thus increasing progressively Landau damping by an order of magnitude at constant electron density and temperature. A delayed 351-nm interaction beam, spatially smoothed to produce a 200-(micro)m laser spot at best focus, has propagated along the axis of the hohlraum. The backscattered light, both into the lens and outside, the transmitted light through the hohlraum plasma and the radiation temperature of the hohlraum has been measured. For ignition relevant laser intensities (3-9 10 14 Wcm -2 ), we find that the SBS reflectivity scales as predicted with Landau damping from >30% to <1%. Simultaneously, the hohlraum radiation

  8. An analysis of the plasma impurity influx from alkali-metal coatings for fusion reactor applications

    International Nuclear Information System (INIS)

    DeWald, A.B.; Davidson, J.N.; Krauss, A.R.; Gruen, D.M.

    1982-01-01

    Recently, it has been proposed that alkali-metal covered surfaces be applied to magnetic fusion devices as a means of controlling plasma impurity contamination and shielding the substrate from erosion. Monolayer films of alkali metals have been shown to sputter primarily as ions under particle bombardment. Thus, it is thought that a sheath potential and/or magnetic fields encountered by a sputtered ion will return the ion to the surface without entering the plasma. In this paper, we investigate the net wall impurity influx associated with coatings which exhibit substantial secondary ion emission compared with those which sputter only as neutral atoms. Included in the analysis are sputtered substrate atoms. These are sometimes found to be a significant fraction of the total sputtering yield for low-Z alkali monolayers and affect the overall performance of such coatings. Estimates of the impurity influx made in the neighborhood of a sheath potential show that secondary-ion emitting coatings are effective as a means of inhibiting plasma impurity contamination and wall erosion. (orig.)

  9. Analysis of the plasma impurity influx from alkali-metal coatings for fusion-reactor applications

    International Nuclear Information System (INIS)

    DeWald, A.B.; Davidson, J.N.; Krauss, A.R.; Gruen, D.M.

    1982-01-01

    Recently, it has been proposed that alkali-metal covered surfaces be applied to magnetic fusion devices as a means of controlling plasma impurity contamination and shielding the substrate from erosion. Monolayer films of alkali metals have been shown to sputter primarily as ions under particle bombardment. Thus, it is thought that a sheath potential and/or magnetic fields encountered by a sputtered ion will return the ion to the surface without entering the plasma. In this paper, we investigate the net wall impurity influx associated with coatings which exhibit substantial secondary ion emission as compared to those which sputter only as neutral atoms. Included in the analysis are sputtered substrate atoms. These are sometimes found to be a significant fraction of the total sputtering yield for low-Z alkali monolayers and affect the overall performance of such coatings. Estimates of the impurity influx made in the neighborhood of a sheath potential show that secondary-ion emitting coatings are effective as a means of inhibiting plasma impurity contamination and wall erosion

  10. IAEA activities on atomic, molecular and plasma-material interaction data for fusion

    Science.gov (United States)

    Braams, Bastiaan J.; Chung, Hyun-Kyung

    2013-09-01

    The IAEA Atomic and Molecular Data Unit (http://www-amdis.iaea.org/) aims to provide internationally evaluated and recommended data for atomic, molecular and plasma-material interaction (A+M+PMI) processes in fusion research. The Unit organizes technical meetings and coordinates an A+M Data Centre Network (DCN) and a Code Centre Network (CCN). In addition the Unit organizes Coordinated Research Projects (CRPs), for which the objectives are mixed between development of new data and evaluation and recommendation of existing data. In the area of A+M data we are placing new emphasis in our meeting schedule on data evaluation and especially on uncertainties in calculated cross section data and the propagation of uncertainties through structure data and fundamental cross sections to effective rate coefficients. Following a recent meeting of the CCN it is intended to use electron scattering on Be, Ne and N2 as exemplars for study of uncertainties and uncertainty propagation in calculated data; this will be discussed further at the presentation. Please see http://www-amdis.iaea.org/CRP/ for more on our active and planned CRPs, which are concerned with atomic processes in core and edge plasma and with plasma interaction with beryllium-based surfaces and with irradiated tungsten.

  11. Neutron time-of-flight counters and spectrometers for diagnostics of burning fusion plasmas

    International Nuclear Information System (INIS)

    Elevant, T.; Olsson, M.

    1991-02-01

    Experiment with burning fusion plasmas in tokamaks will place particular requirements on neutron measurements from radiation resistance-, physics-, burn control- and reliability considerations. The possibility to meet these needs by measurements of neutron fluxes and energy spectra by means of time-of-flight techniques are described. Reference counters and spectrometers are proposed and characterized with respect to efficiency, count-rate capabilities, energy resolution and tolerable neutron and γ-radiation background levels. The instruments can be used in a neutron camera and are capable to operate in collimated neutron fluxes up to levels corresponding to full nuclear output power in the next generation of experiments. Energy resolutions of the spectrometers enables determination of ion temperatures from 3 (keV) through analysis of the Doppler broadening. Primarily, the instruments are aimed for studies of 14 (MeV) neutrons produced in (d,t)-plasmas but can, after minor modifications, be used for analysis of 2.45 (MeV) neutrons produced in (d,d)-plasma. (au) (33 refs.)

  12. Laser-Plasma Interactions on NIKE and the Fusion Test Facility

    Science.gov (United States)

    Phillips, Lee; Weaver, James

    2008-11-01

    Recent proposed designs for a Fusion Test Facility (FTF) (Obenchain et al., Phys. Plasmas 13 056320 (2006)) for direct-drive ICF targets for energy applications involve high implosion velocities combined with higher laser irradiances. The use of high irradiances increases the likelihood of deleterious laser plasma instabilities (LPI) but the proposed use of a 248 nm KrF laser to drive these targets is expected to minimize the LPI risk. We examine, using simulation results from NRL's FAST hydrocode, the proposed operational regimes of the FTF in relation to the thresholds for the SRS, SBS, and 2-plasmon instabilities. Simulations are also used to help design and interpret ongoing experiments being conducted at NRL's NIKE facility for the purpose of generating and studying LPI. Target geometries and laser pulseshapes were devised in order to create plasma conditions with long scalelengths and low electron temperatures that allow the growth of parametric instabilities. These simulations include the effects of finite beam angles through the use of raytracing.

  13. Multi parametric sensitivity study applied to temperature measurement of metallic plasma facing components in fusion devices

    International Nuclear Information System (INIS)

    Aumeunier, M-H.; Corre, Y.; Firdaouss, M.; Gauthier, E.; Loarer, T.; Travere, J-M.; Gardarein, J-L.; EFDA JET Contributor

    2013-06-01

    In nuclear fusion experiments, the protection system of the Plasma Facing Components (PFCs) is commonly ensured by infrared (IR) thermography. Nevertheless, the surface monitoring of new metallic plasma facing component, as in JET and ITER is being challenging. Indeed, the analysis of infrared signals is made more complicated in such a metallic environment since the signals will be perturbed by the reflected photons coming from high temperature regions. To address and anticipate this new measurement environment, predictive photonic models, based on Monte-Carlo ray tracing (SPEOS R CAA V5 Based), have been performed to assess the contribution of the reflective part in the total flux collected by the camera and the resulting temperature error. This paper deals with the effects of metals features, as the emissivity and reflectivity models, on the accuracy of the surface temperature estimation. The reliability of the features models is discussed by comparing the simulation with experimental data obtained with the wide angle IR thermography system of JET ITER like wall. The impact of the temperature distribution is studied by considering two different typical plasma scenarios, in limiter (ITER start-up scenario) and in X-point configurations (standard divertor scenario). The achievable measurement performances of IR system and risks analysis on its functionalities are discussed. (authors)

  14. Interactions between plasma and wall materials in fusion reactors; Plasma-Wand Wechselwirkungen von Fusionsreaktormaterialien

    Energy Technology Data Exchange (ETDEWEB)

    Marot, L.; Moser, L.; and others

    2016-11-15

    First mirrors of optical diagnostics in ITER were exposed in Magnum-PSI linear plasma device and JET-ILW tokamak. For JET-ILW the mirrors with a rhodium (Rh) or a molybdenum (Mo) coating exhibited a decrease of the reflectivity according the location in the torus and especially the amount of beryllium (Be) deposited on them. No delamination of the coated reflective film was observed. Under very harsh erosion conditions in Magnum-PSI, Rh thick coated mock ups, cooled or not, for a high flux exposure the films underwent delamination. Mo coating on water cooled mock up mirrors exhibited a high diffuse reflectivity after H{sub 2}/Ar plasma exposure inducing an important decrease of the specular reflectivity and show important oxidation of the surface. Cleaning of mirrors was extensively studied during this period, with magnetic field in collaboration with the SPC Lausanne, or in term of repetitive cleaning till 34 cycles. Polycrystalline molybdenum mirror shows a high diffuse reflectivity after cleaning cycle and clearly demonstrate that they are not suitable for this purpose. Coated Rh or Mo mirrors like single crystal maintained good reflectivity. Test under magnetic field revealed the non-uniform erosion of the mirrors according the orientation between the field and the mirror. All these tests bring to a suitable schematic of the implementation of this technique in ITER and were deeply explained. The cleaning of the Be contaminated mirrors will be carried out using new parameters in December 2016. Investigations on formation of tungsten fuzz were carried out either in Basel using a new setup or in Pilot-PSI. These thickness measurements showed the fuzz growth is in square root dependence to time or fluence. From the results in Pilot-PSI, it has been shown that time was a critical parameter for the development of He-induced morphology changes and one needs to keep that factor in mind. (authors)

  15. Predictive modelling of edge transport phenomena in ELMy H-mode tokamak fusion plasmas

    International Nuclear Information System (INIS)

    Loennroth, J.-S.

    2009-01-01

    This thesis discusses a range of work dealing with edge plasma transport in magnetically confined fusion plasmas by means of predictive transport modelling, a technique in which qualitative predictions and explanations are sought by running transport codes equipped with models for plasma transport and other relevant phenomena. The focus is on high confinement mode (H-mode) tokamak plasmas, which feature improved performance thanks to the formation of an edge transport barrier. H-mode plasmas are generally characterized by the occurrence of edge localized modes (ELMs), periodic eruptions of particles and energy, which limit confinement and may turn out to be seriously damaging in future tokamaks. The thesis introduces schemes and models for qualitative study of the ELM phenomenon in predictive transport modelling. It aims to shed new light on the dynamics of ELMs using these models. It tries to explain various experimental observations related to the performance and ELM-behaviour of H-mode plasmas. Finally, it also tries to establish more generally the potential effects of ripple-induced thermal ion losses on H-mode plasma performance and ELMs. It is demonstrated that the proposed ELM modelling schemes can qualitatively reproduce the experimental dynamics of a number of ELM regimes. Using a theory-motivated ELM model based on a linear instability model, the dynamics of combined ballooning-peeling mode ELMs is studied. It is shown that the ELMs are most often triggered by a ballooning mode instability, which renders the plasma peeling mode unstable, causing the ELM to continue in a peeling mode phase. Understanding the dynamics of ELMs will be a key issue when it comes to controlling and mitigating the ELMs in future large tokamaks. By means of integrated modelling, it is shown that an experimentally observed increase in the ELM frequency and deterioration of plasma confinement triggered by external neutral gas puffing might be due to a transition from the second to

  16. Parallel processing for a 1-D time-dependent solution to impurity rate equations for fusion plasma simulations

    International Nuclear Information System (INIS)

    Veerasingam, R.

    1990-01-01

    In fusion plasmas impurities such as carbon, oxygen or nickel can contaminate the plasma and cause degradation of the performance of a fusion device through radiation. However, impurities can also be used as diagnostics to obtain information about a plasma through spectroscopic experiments which can then be used in plasma modeling and simulations. In the past, serial algorithms have been described for either the time dependent or steady state problem. In this paper, we describe a parallel procedure adopted to solve the time-dependent problem. It can be shown that for the steady state problem a parallel procedure would not be a useful application of parallelization because a few seconds of the Central Processing Unit time on a CRAY-XMP or IBM 3090/600S would suffice to obtain the solution, while this is not the case for the time-dependent problem. In order to study the effects of low Z and high Z impurities on the final state of a plasma, time-dependent solutions are necessary. For purposes of diagnostics and comparisons with experiments, a fast turn around time of the simulations would be advantageous. We have implemented a parallel algorithm on and IBM 3090/600S and tested its performance for a typical set of fusion plasma parameters. 4 refs., 1 tab

  17. Proceedings of the US-Japan workshop and the satellite meeting of ITC-9 on physics of high beta plasma confinement in innovative fusion system

    International Nuclear Information System (INIS)

    Goto, Seiichi; Yoshimura, Satoru

    1999-04-01

    The US-Japan Workshop on Physics of High Beta Plasma Confinement in Innovative Fusion System was held jointly with the Satellite Meeting of ITC-9 at National Institute for Fusion Science (NIFS), Toki-city during December 14-15, 1998. This proceedings book includes the papers of the talks given at the workshop. These include: Theoretical analysis on the stability of field reversed configuration (FRC) plasmas; Theory and Modeling of high β plasmas; Recent progressive experiments in high β systems; Formation of high β plasmas using merging phenomenon; Theory and Modeling of a FRC Fusion Reactor. The 15 papers are indexed individually. (J.P.N.)

  18. Proceedings of the US-Japan workshop and the satellite meeting of ITC-9 on physics of high beta plasma confinement in innovative fusion system

    Energy Technology Data Exchange (ETDEWEB)

    Goto, Seiichi; Yoshimura, Satoru [eds.

    1999-04-01

    The US-Japan Workshop on Physics of High Beta Plasma Confinement in Innovative Fusion System was held jointly with the Satellite Meeting of ITC-9 at National Institute for Fusion Science (NIFS), Toki-city during December 14-15, 1998. This proceedings book includes the papers of the talks given at the workshop. These include: Theoretical analysis on the stability of field reversed configuration (FRC) plasmas; Theory and Modeling of high {beta} plasmas; Recent progressive experiments in high {beta} systems; Formation of high {beta} plasmas using merging phenomenon; Theory and Modeling of a FRC Fusion Reactor. The 15 papers are indexed individually. (J.P.N.)

  19. Effects of fusion relevant transient energetic radiation, plasma and thermal load on PLANSEE double forged tungsten samples in a low-energy plasma focus device

    Science.gov (United States)

    Javadi, S.; Ouyang, B.; Zhang, Z.; Ghoranneviss, M.; Salar Elahi, A.; Rawat, R. S.

    2018-06-01

    Tungsten is the leading candidate for plasma facing component (PFC) material for thermonuclear fusion reactors and various efforts are ongoing to evaluate its performance or response to intense fusion relevant radiation, plasma and thermal loads. This paper investigates the effects of hot dense decaying pinch plasma, highly energetic deuterium ions and fusion neutrons generated in a low-energy (3.0 kJ) plasma focus device on the structure, morphology and hardness of the PLANSEE double forged tungsten (W) samples surfaces. The tungsten samples were provided by Forschungszentrum Juelich (FZJ), Germany via International Atomic Energy Agency, Vienna, Austria. Tungsten samples were irradiated using different number of plasma focus (PF) shots (1, 5 and 10) at a fixed axial distance of 5 cm from the anode top and also at various distances from the top of the anode (5, 7, 9 and 11 cm) using fixed number (5) of plasma focus shots. The virgin tungsten sample had bcc structure (α-W phase). After PF irradiation, the XRD analysis showed (i) the presence of low intensity new diffraction peak corresponding to β-W phase at (211) crystalline plane indicating the partial structural phase transition in some of the samples, (ii) partial amorphization, and (iii) vacancy defects formation and compressive stress in irradiated tungsten samples. Field emission scanning electron microscopy showed the distinctive changes to non-uniform surface with nanometer sized particles and particle agglomerates along with large surface cracks at higher number of irradiation shots. X-ray photoelectron spectroscopy analysis demonstrated the reduction in relative tungsten oxide content and the increase in metallic tungsten after irradiation. Hardness of irradiated samples initially increased for one shot exposure due to reduction in tungsten oxide phase, but then decreased with increasing number of shots due to increasing concentration of defects. It is demonstrated that the plasma focus device provides

  20. Characterization of the axial plasma shock in a table top plasma focus after the pinch and its possible application to testing materials for fusion reactors

    Energy Technology Data Exchange (ETDEWEB)

    Soto, Leopoldo, E-mail: lsoto@cchen.cl; Pavez, Cristian; Moreno, José [Comisión Chilena de Energía Nuclear, Casilla 188-D, Santiago (Chile); Centro de Investigación y Aplicaciones en Física de Plasmas y Potencia Pulsada, P" 4, Santiago-Talca (Chile); Departamento de Ciencias Físicas, Facultad de Ciencias Exactas, Universidad Andrés Bello, República 220, Santiago (Chile); Inestrosa-Izurieta, María José [Comisión Chilena de Energía Nuclear, Casilla 188-D, Santiago (Chile); Centro de Investigación y Aplicaciones en Física de Plasmas y Potencia Pulsada, P" 4, Santiago-Talca (Chile); Veloso, Felipe [Instituto de Física, Pontificia Universidad Católica de Chile, Santiago (Chile); Gutiérrez, Gonzalo [Departamento de Física, Facultad de Ciencias, Universidad de Chile, Santiago (Chile); Vergara, Julio [Facultad de Ingeniería, Pontificia Universidad Católica de Chile, Santiago (Chile); Clausse, Alejandro [CNEA-CONICET and Universidad Nacional del Centro, 7000 Tandil (Argentina); Bruzzone, Horacio [CONICET and Universidad de Mar del Plata, Mar del Plata (Argentina); Castillo, Fermín [Instituto de Ciencias Físicas, Universidad Nacional Autónoma de México, Cuernavaca, Morelos (Mexico); and others

    2014-12-15

    The characterization of plasma bursts produced after the pinch phase in a plasma focus of hundreds of joules, using pulsed optical refractive techniques, is presented. A pulsed Nd-YAG laser at 532 nm and 8 ns FWHM pulse duration was used to obtain Schlieren images at different times of the plasma dynamics. The energy, interaction time with a target, and power flux of the plasma burst were assessed, providing useful information for the application of plasma focus devices for studying the effects of fusion-relevant pulses on material targets. In particular, it was found that damage factors on targets of the order of 10{sup 4} (W/cm{sup 2})s{sup 1/2} can be obtained with a small plasma focus operating at hundred joules.

  1. Characterization of the axial plasma shock in a table top plasma focus after the pinch and its possible application to testing materials for fusion reactors

    International Nuclear Information System (INIS)

    4, Santiago-Talca (Chile); Departamento de Ciencias Físicas, Facultad de Ciencias Exactas, Universidad Andrés Bello, República 220, Santiago (Chile))" data-affiliation=" (Comisión Chilena de Energía Nuclear, Casilla 188-D, Santiago (Chile); Centro de Investigación y Aplicaciones en Física de Plasmas y Potencia Pulsada, P4, Santiago-Talca (Chile); Departamento de Ciencias Físicas, Facultad de Ciencias Exactas, Universidad Andrés Bello, República 220, Santiago (Chile))" >Soto, Leopoldo; 4, Santiago-Talca (Chile); Departamento de Ciencias Físicas, Facultad de Ciencias Exactas, Universidad Andrés Bello, República 220, Santiago (Chile))" data-affiliation=" (Comisión Chilena de Energía Nuclear, Casilla 188-D, Santiago (Chile); Centro de Investigación y Aplicaciones en Física de Plasmas y Potencia Pulsada, P4, Santiago-Talca (Chile); Departamento de Ciencias Físicas, Facultad de Ciencias Exactas, Universidad Andrés Bello, República 220, Santiago (Chile))" >Pavez, Cristian; 4, Santiago-Talca (Chile); Departamento de Ciencias Físicas, Facultad de Ciencias Exactas, Universidad Andrés Bello, República 220, Santiago (Chile))" data-affiliation=" (Comisión Chilena de Energía Nuclear, Casilla 188-D, Santiago (Chile); Centro de Investigación y Aplicaciones en Física de Plasmas y Potencia Pulsada, P4, Santiago-Talca (Chile); Departamento de Ciencias Físicas, Facultad de Ciencias Exactas, Universidad Andrés Bello, República 220, Santiago (Chile))" >Moreno, José; 4, Santiago-Talca (Chile))" data-affiliation=" (Comisión Chilena de Energía Nuclear, Casilla 188-D, Santiago (Chile); Centro de Investigación y Aplicaciones en Física de Plasmas y Potencia Pulsada, P4, Santiago-Talca (Chile))" >Inestrosa-Izurieta, María José; Veloso, Felipe; Gutiérrez, Gonzalo; Vergara, Julio; Clausse, Alejandro; Bruzzone, Horacio; Castillo, Fermín

    2014-01-01

    The characterization of plasma bursts produced after the pinch phase in a plasma focus of hundreds of joules, using pulsed optical refractive techniques, is presented. A pulsed Nd-YAG laser at 532 nm and 8 ns FWHM pulse duration was used to obtain Schlieren images at different times of the plasma dynamics. The energy, interaction time with a target, and power flux of the plasma burst were assessed, providing useful information for the application of plasma focus devices for studying the effects of fusion-relevant pulses on material targets. In particular, it was found that damage factors on targets of the order of 10 4 (W/cm 2 )s 1/2 can be obtained with a small plasma focus operating at hundred joules

  2. Probing plasma membrane microdomains in cowpea protoplasts using lipidated GFP-fusion proteins and multimode FRET microscopy

    NARCIS (Netherlands)

    Vermeer, J.E.M.; van Munster, E.B.; Vischer, N.O.; Gadella, T.

    2004-01-01

    Multimode fluorescence resonance energy transfer (FRET) microscopy was applied to study the plasma membrane organization using different lipidated green fluorescent protein (GFP)-fusion proteins co-expressed in cowpea protoplasts. Cyan fluorescent protein (CFP) was fused to the hyper variable region

  3. JSPS-CAS Core University Program seminar on summary of 10-year collaborations in plasma and nuclear fusion research area

    International Nuclear Information System (INIS)

    Toi, Kazuo; Wang Kongjia

    2011-07-01

    The JSPS-CAS Core University Program (CUP) seminar on “Summary of 10-year Collaborations in Plasma and Nuclear Fusion Research Area” was held from March 9 to March 11, 2011 in the Okinawa Prefectural Art Museum, Naha city, Okinawa, Japan. The collaboration program on plasma and nuclear fusion started from 2001 under the auspices of Japanese Society of Promotion of Science (JSPS) and Chinese Academy of Sciences (CAS). This year is the last year of the CUP. This seminar was organized in the framework of the CUP. In the seminar, 29 oral talks were presented, having 14 Chinese and 30 Japanese participants. These presentations covered key topics related to the collaboration categories: (1) improvement of core plasma properties, (2) basic research on fusion reactor technologies, and (3) theory and numerical simulation. This seminar aims at summarizing the results obtained through the collaborations for 10 years, and discussing future prospects of China-Japan collaboration in plasma and nuclear fusion research areas. (author)

  4. 1st IAEA research co-ordination meeting on charge exchange cross section data for fusion plasma studies. Summary report

    International Nuclear Information System (INIS)

    Janev, R.K.

    1999-02-01

    A brief description of the proceedings and the conclusions of the 1st Research Coordination Meeting on 'Charge Exchange Cross Section Data for Fusion Plasma Studies', held on September 24-25, 1999, at the IAEA Headquarters in Vienna, Austria, is provided. The conclusions of the Meeting regarding the data collection, assessment and generation priorities are also included in the report. (author)

  5. IAEA technical meeting on atomic and plasma-material interaction data for fusion science technology. Summary report

    International Nuclear Information System (INIS)

    Clark, R.E.H.

    2003-10-01

    The proceedings and conclusions of the Technical Meeting on 'Atomic and Plasma- Material Interaction Data for Fusion Science Technology' held in Juelich, Germany on October 28-31 are summarized. During the course of the meetings working groups were formed to review the status of specific areas of atomic, molecular and material physics of relevance to fusion and to make recommendations on data needs in fusion from these areas. The reports of those working groups are summarized and the complete reports included as appendices. This meeting brought together over fifty leading scientists in fusion related data. Results of research in a number of topics were presented and very useful discussions were held. The meeting was extremely successful. (author)

  6. Numerical Design of Megawatt Gyrotron with 120 GHz Frequency and 50% Efficiency for Plasma Fusion Application

    Science.gov (United States)

    Kumar, Nitin; Singh, Udaybir; Kumar, Anil; Bhattacharya, Ranajoy; Singh, T. P.; Sinha, A. K.

    2013-02-01

    The design of 120 GHz, 1 MW gyrotron for plasma fusion application is presented in this paper. The mode selection is carried out considering the aim of minimum mode competition, minimum cavity wall heating, etc. On the basis of the selected operating mode, the interaction cavity design and beam-wave interaction computation are carried out by using the PIC code. The design of triode type Magnetron Injection Gun (MIG) is also presented. Trajectory code EGUN, synthesis code MIGSYN and data analysis code MIGANS are used in the MIG designing. Further, the design of MIG is also validated by using the another trajectory code TRAK. The design results of beam dumping system (collector) and RF window are also presented. Depressed collector is designed to enhance the overall tube efficiency. The design study confirms >1 MW output power with tube efficiency around 50% (with collector efficiency).

  7. Three-dimensional modeling of beam emission spectroscopy measurements in fusion plasmas

    Energy Technology Data Exchange (ETDEWEB)

    Guszejnov, D.; Pokol, G. I. [Department of Nuclear Techniques, Budapest University of Technology and Economics, Association EURATOM, H-1111 Budapest (Hungary); Pusztai, I. [Nuclear Engineering, Applied Physics, Chalmers University of Technology, SE-412 96 Goeteborg (Sweden); Refy, D.; Zoletnik, S. [MTA Wigner FK RMI, Association EURATOM, Pf. 49, H-1525 Budapest (Hungary); Lampert, M. [Department of Nuclear Techniques, Budapest University of Technology and Economics, Association EURATOM, H-1111 Budapest (Hungary); MTA Wigner FK RMI, Association EURATOM, Pf. 49, H-1525 Budapest (Hungary); Nam, Y. U. [National Fusion Research Institute, Gwahangno 113, Daejeon 305-333 (Korea, Republic of)

    2012-11-15

    One of the main diagnostic tools for measuring electron density profiles and the characteristics of long wavelength turbulent wave structures in fusion plasmas is beam emission spectroscopy (BES). The increasing number of BES systems necessitated an accurate and comprehensive simulation of BES diagnostics, which in turn motivated the development of the Rate Equations for Neutral Alkali-beam TEchnique (RENATE) simulation code that is the topic of this paper. RENATE is a modular, fully three-dimensional code incorporating all key features of BES systems from the atomic physics to the observation, including an advanced modeling of the optics. Thus RENATE can be used both in the interpretation of measured signals and the development of new BES systems. The most important components of the code have been successfully benchmarked against other simulation codes. The primary results have been validated against experimental data from the KSTAR tokamak.

  8. Gravitational Contraction and Fusion Plasma Burn. Universal Expansion and the Hubble Law

    International Nuclear Information System (INIS)

    Wilhelmsson, Hans

    2002-01-01

    A dynamic approach is developed for the two principle phases of (i) gravitational condensation, and (ii) burning fusion plasma evolution. Comparison is made with conceptual descriptions of star formation and of subsequent decay towards red giant stars, white dwarfs, and other condensed core objects like neutron stars and black holes. The possibility of treating the expansion of the Universe by means of a similar approach is also discussed. The concept of negative diffusion is introduced for the contraction phase of star formation. The coefficients of defining the nonlinear diffusion are determined uniquely by physical conditions and for the case of the expansion of the universe, by the observation of the Hubble law. The contraction and evolution of large scale 3-D stars and 2-D galactic systems can thus be dynamically surveyed. In particular the time-scales can be determined

  9. The manufacture of carbon armoured plasma-facing components for fusion devices

    International Nuclear Information System (INIS)

    Schedler, B.; Huber, T.; Zabernig, A.; Rainer, F.; Scheiber, K.H.; Schedle, D.

    2001-01-01

    Within the last decade Plansee has been active in the development and manufacture of different plasma-facing-components for nuclear fusion experiments consisting in a tungsten or CFC-armor joined onto metallic substrates like TZM, stainless steel or copper-alloys. The manufacture of these components requires unique joining technologies in order to obtain reliable thermo mechanical stable joints able to withstand highest heat fluxes without any deterioration of the joint. In an overview the different techniques will be presented by some examples of components already manufactured and successfully tested under high heat flux conditions. Furthermore an overview will be given on the manufacture of different high heat flux components for TORE SUPRA, Wendelstein 7-X and ITER. (author)

  10. Far-infrared imaging arrays for fusion plasma density and magnetic field measurements

    International Nuclear Information System (INIS)

    Neikirk, D.P.; Rutledge, D.B.

    1982-01-01

    Far-infrared imaging detector arrays are required for the determination of density and local magnetic field in fusion plasmas. Analytic calculations point out the difficulties with simple printed slot and dipole antennas on ungrounded substrates for use in submillimeter wave imaging arrays because of trapped surface waves. This is followed by a discussion of the use of substrate-lens coupling to eliminate the associated trapped surface modes responsible for their poor performance. This integrates well with a modified bow-tie antenna and permits diffraction-limited imaging. Arrays using bismuth microbolometers have been successfully fabricated and tested at 1222μm and 119μm. A 100 channel pilot experiment designed for the UCLA Microtor tokamak is described. (author)

  11. Characterization of a segmented plasma torch assisted High Heat Flux (HHF) system for performance evaluation of plasma facing components in fusion devices

    International Nuclear Information System (INIS)

    Ngangom, Aomoa; Sarmah, Trinayan; Sah, Puspa; Kakati, Mayur; Ghosh, Joydeep

    2015-01-01

    A wide variety of high heat and particle flux test facilities are being used by the fusion community to evaluate the thermal performance of plasma facing materials/components, which includes electron beam, ion beam, neutral beam and thermal plasma assisted sources. In addition to simulate heat loads, plasma sources have the additional advantage of reproducing exact fusion plasma like conditions, in terms of plasma density, temperature and particle flux. At CPP-IPR, Assam, we have developed a high heat and particle flux facility using a DC, non-transferred, segmented thermal plasma torch system, which can produce a constricted, stabilized plasma jet with high ion density. In this system, the plasma torch exhausts into a low pressure chamber containing the materials to be irradiated, which produces an expanded plasma jet with more uniform profiles, compared to plasma torches operated at atmospheric pressure. The heat flux of the plasma beam was studied by using circular calorimeters of different diameters (2 and 3 cm) for different input power (5-55 kW). The effect of the change in gas (argon) flow rate and mixing of gases (argon + hydrogen) was also studied. The heat profile of the plasma beam was also studied by using a pipe calorimeter. From this, the radial heat flux was calculated by using Abel inversion. It is seen that the required heat flux of 10 MW/m 2 is achievable in our system for pure argon plasma as well as for plasma with gas mixtures. The plasma parameters like the temperature, density and the beam velocity were studied by using optical emission spectroscopy. For this, a McPherson made 1.33 meter focal length spectrometer; model number 209, was used. A plane grating with 1800 g/mm was used which gave a spectral resolution of 0.007 nm. A detailed characterization with respect to these plasma parameters for different gas (argon) flow rate and mixing of gases (argon+hydrogen) for different input power will be presented in this paper. The plasma

  12. Membrane fusion

    DEFF Research Database (Denmark)

    Bendix, Pól Martin

    2015-01-01

    At Stanford University, Boxer lab, I worked on membrane fusion of small unilamellar lipid vesicles to flat membranes tethered to glass surfaces. This geometry closely resembles biological systems in which liposomes fuse to plasma membranes. The fusion mechanism was studied using DNA zippering...... between complementary strands linked to the two apposing membranes closely mimicking the zippering mechanism of SNARE fusion complexes....

  13. FOREWORD: 13th International Workshop on Plasma-Facing Materials and Components for Fusion Applications/1st International Conference on Fusion Energy Materials Science 13th International Workshop on Plasma-Facing Materials and Components for Fusion Applications/1st International Conference on Fusion Energy Materials Science

    Science.gov (United States)

    Jacob, Wolfgang; Linsmeier, Christian; Rubel, Marek

    2011-12-01

    The 13th International Workshop on Plasma-Facing Materials and Components (PFMC-13) jointly organized with the 1st International Conference on Fusion Energy Materials Science (FEMaS-1) was held in Rosenheim (Germany) on 9-13 May 2011. PFMC-13 is a successor of the International Workshop on Carbon Materials for Fusion Applications series. Between 1985 and 2003 ten 'Carbon Workshops' were organized in Jülich, Stockholm and Hohenkammer. Then it was time for a change and redefinition of the scope of the symposium to reflect the new requirements of ITER and the ongoing evolution in the field. Under the new name (PFMC-11), the workshop was first organized in 2006 in Greifswald, Germany and PFMC-12 took place in Jülich in 2009. Initially starting in 1985 with about 40 participants as a 1.5 day workshop, the event has continuously grown to about 220 participants at PFMC-12. Due to the joint organization with FEMaS-1, PFMC-13 set a new record with more than 280 participants. The European project Fusion Energy Materials Science, FEMaS, coordinated by the Max-Planck-Institut für Plasmaphysik (IPP), organizes and stimulates cooperative research activities which involve large-scale research facilities as well as other top-level materials characterization laboratories. Five different fields are addressed: benchmarking experiments for radiation damage modelling, the application of micro-mechanical characterization methods, synchrotron and neutron radiation-based techniques and advanced nanoscopic analysis based on transmission electron microscopy. All these fields need to be exploited further by the fusion materials community for timely materials solutions for a DEMO reactor. In order to integrate these materials research fields, FEMaS acted as a co-organizer for the 2011 workshop and successfully introduced a number of participants from research labs and universities into the PFMC community. Plasma-facing materials experience particularly hostile conditions as they are

  14. High-power microwave transmission and launching systems for fusion plasma heating systems

    International Nuclear Information System (INIS)

    Bigelow, T.S.

    1989-01-01

    Microwave power in the 30- to 300-GHz frequency range is becoming widely used for heating of plasma in present-day fusion energy magnetic confinement experiments. Microwave power is effective in ionizing plasma and heating electrons through the electron cyclotron heating (ECH) process. Since the power is absorbed in regions of the magnetic field where resonance occurs and launching antennas with narrow beam widths are possible, power deposition location can be highly controlled. This is important for maximizing the power utilization efficiency and improving plasma parameters. Development of the gyrotron oscillator tube has advanced in recent years so that a 1-MW continuous-wave, 140-GHz power source will soon be available. Gyrotron output power is typically in a circular waveguide propagating a circular electric mode (such as TE 0,2 ) or a whispering-gallery mode (such as TE 15,2 ), depending on frequency and power level. An alternative high-power microwave source currently under development is the free-electron laser (FEL), which may be capable of generating 2-10 MW of average power at frequencies of up to 500 GHz. The FEL has a rectangular output waveguide carrying the TE 0,1 mode. Because of its higher complexity and cost, the high-average-power FEL is not yet as extensively developed as the gyrotron. In this paper, several types of operating ECH transmission systems are discussed, as well systems currently being developed. The trend in this area is toward higher power and frequency due to the improvements in plasma density and temperature possible. Every system requires a variety of components, such as mode converters, waveguide bends, launchers, and directional couplers. Some of these components are discussed here, along with ongoing work to improve their performance. 8 refs

  15. 2001 activity report of the development and research line in controlled thermonuclear fusion of the Plasma Associated Laboratory; Relatorio de atividades de 2001 da linha de pesquisa e desenvolvimento em fusao termonuclear controlada (fusao), do Laboratorio Associado de Plasma (LAP)

    Energy Technology Data Exchange (ETDEWEB)

    Ludwig, Gerson Otto

    2002-07-01

    The year 2001 activities of the controlled thermonuclear fusion research line of the Plasma Associated Laboratory at the National Institute for Space Research - Brazil are reported. The report approaches the staff, participation in congresses, goals for the year 2002 and papers on Tokamak plasmas, plasma diagnostic, bootstraps, plasma equilibrium and diagnostic.

  16. SciDAC Fusiongrid Project--A National Collaboratory to Advance the Science of High Temperature Plasma Physics for Magnetic Fusion

    Energy Technology Data Exchange (ETDEWEB)

    SCHISSEL, D.P.; ABLA, G.; BURRUSS, J.R.; FEIBUSH, E.; FREDIAN, T.W.; GOODE, M.M.; GREENWALD, M.J.; KEAHEY, K.; LEGGETT, T.; LI, K.; McCUNE, D.C.; PAPKA, M.E.; RANDERSON, L.; SANDERSON, A.; STILLERMAN, J.; THOMPSON, M.R.; URAM, T.; WALLACE, G.

    2006-08-31

    portion of national program efforts are organized around coordinated efforts to develop promising operational scenarios. Substantial efforts to develop integrated plasma modeling codes are also underway in the U.S., Europe and Japan. As a result of the highly collaborative nature of FES research, the community is facing new and unique challenges. While FES has a significant track record for developing and exploiting remote collaborations, with such large investments at stake, there is a clear need to improve the integration and reach of available tools. The NFC Project was initiated to address these challenges by creating and deploying collaborative software tools. The original objective of the NFC project was to develop and deploy a national FES 'Grid' (FusionGrid) that would be a system for secure sharing of computation, visualization, and data resources over the Internet. The goal of FusionGrid was to allow scientists at remote sites to participate as fully in experiments and computational activities as if they were working on site thereby creating a unified virtual organization of the geographically dispersed U.S. fusion community. The vision for FusionGrid was that experimental and simulation data, computer codes, analysis routines, visualization tools, and remote collaboration tools are to be thought of as network services. In this model, an application service provider (ASP) provides and maintains software resources as well as the necessary hardware resources. The project would create a robust, user-friendly collaborative software environment and make it available to the US FES community. This Grid's resources would be protected by a shared security infrastructure including strong authentication to identify users and authorization to allow stakeholders to control their own resources. In this environment, access to services is stressed rather than data or software portability.

  17. Sausage instabilities stabilized by radial motion in Z-discharged plasma channel for beam propagation in LIB-fusion

    International Nuclear Information System (INIS)

    Murakami, Hiroyuki; Kawata, Shigeo; Niu, Keishiro.

    1983-01-01

    The stability of current-carrying plasma channels, which have been proposed for transporting intense ion beams from the diodes to the target in LIB-fusion devices, is discussed. The growth rate of the most dangerous surface mode, that is, the axisymmetric sausage instabilities, are examined for plasma channels with or without radial fluid motion. The growth rate of the channel with radial fluid motion is shown to be far smaller than that of the channel with no fluid motion. It is concluded that a stable plasma channel can be formed by radial fluid motion. (author)

  18. Perspective on the Role of Negative Ions and Ion-Ion Plasmas in Heavy Ion Fusion Science, Magnetic Fusion Energy, and Related Fields

    International Nuclear Information System (INIS)

    Grisham, L.R.; Kwan, J.W.

    2008-01-01

    Some years ago it was suggested that halogen negative ions (1)could offer a feasible alternative path to positive ions as a heavy ion fusion driver beam which would not suffer degradation due to electron accumulation in the accelerator and beam transport system, and which could be converted to a neutral beam by photodetachment near the chamber entrance if desired. Since then, experiments have demonstrated that negative halogen beams can be extracted and accelerated away from the gas plume near the source with a surviving current density close to what could be achieved with a positive ion of similar mass, and with comparable optical quality. In demonstrating the feasibility of halogen negative ions as heavy ion driver beams, ion-ion plasmas, an interesting and somewhat novel state of matter, were produced. These plasmas, produced near the extractor plane of the sources, appear, based upon many lines of experimental evidence, to consist of almost equal densities of positive and negative chlorine ions, with only a small component of free electrons. Serendipitously, the need to extract beams from this plasma for driver development provides a unique diagnostic tool to investigate the plasma, since each component--positive ions, negative ions, and electrons--can be extracted and measured separately. We discuss the relevance of these observations to understanding negative ion beam extraction from electronegative plasmas such as halogens, or the more familiar hydrogen of magnetic fusion ion sources. We suggest a concept which might improve negative hydrogen extraction by the addition of a halogen. The possibility and challenges of producing ion-ion plasmas with thin targets of halogens or, perhaps, salt, is briefly addressed

  19. Perspective on the Role of Negative Ions and Ion-Ion Plasmas in Heavy Ion Fusion Science, Magnetic Fusion Energy,and Related Fields

    International Nuclear Information System (INIS)

    Grisham, L.R.; Kwan, J.W.

    2008-01-01

    Some years ago it was suggested that halogen negative ions could offer a feasible alternative path to positive ions as a heavy ion fusion driver beam which would not suffer degradation due to electron accumulation in the accelerator and beam transport system, and which could be converted to a neutral beam by photodetachment near the chamber entrance if desired. Since then, experiments have demonstrated that negative halogen beams can be extracted and accelerated away from the gas plume near the source with a surviving current density close to what could be achieved with a positive ion of similar mass, and with comparable optical quality. In demonstrating the feasibility of halogen negative ions as heavy ion driver beams, ion - ion plasmas, an interesting and somewhat novel state of matter, were produced. These plasmas, produced near the extractor plane of the sources, appear, based upon many lines of experimental evidence, to consist of almost equal densities of positive and negative chlorine ions, with only a small component of free electrons. Serendipitously, the need to extract beams from this plasma for driver development provides a unique diagnostic tool to investigate the plasma, since each component - positive ions, negative ions, and electrons - can be extracted and measured separately. We discuss the relevance of these observations to understanding negative ion beam extraction from electronegative plasmas such as halogens, or the more familiar hydrogen of magnetic fusion ion sources. We suggest a concept which might improve negative hydrogen extraction by the addition of a halogen. The possibility and challenges of producing ion - ion plasmas with thin targets of halogens or, perhaps, salt, is briefly addressed.

  20. Simulations of phenomena related to edge transport in tokamak fusion plasmas

    International Nuclear Information System (INIS)

    Konzett, S.

    2011-01-01

    This thesis investigates turbulence in a tokamak fusion plasma using numerical simulations. The fluid turbulence code ATTEMPT, which computes the drift dynamics of ions and electrons in electromagnetic fields, is applied to investigate three physical effects which are motivated by recent experimental findings. The first part shows that the statistics of drift fluid turbulence are largely unaffected by the presence of rational magnetic surfaces for typical edge parameter regimes. The second part contains an analysis of the dependence of correlation lengths on various physical parameters. A systematic approach reveals the impact of plasma parameters - which change in the transition from L to H-mode - on parallel, radial and perpendicular correlation lengths. In the last part of the thesis a new flux surface geometry is implemented in the ATTEMPT code. The modified geometry models the onset of the change in magnetic topology near a magnetic X-point. Computations show that turbulent fluctuations are reduced in an X-point distorted flux surface geometry, and the spectral structure of turbulence is altered substantially. (author) [de