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Book High Power Ion Cyclotron Resonance Heating in JET

Download or read book High Power Ion Cyclotron Resonance Heating in JET written by Commission of the European Communities, Abingdon. JETJointUndertaking and published by . This book was released on 1988 with total page 12 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Book High Power Ion Cyclotron Resonance Heating ICRH in JET

Download or read book High Power Ion Cyclotron Resonance Heating ICRH in JET written by and published by . This book was released on 1988 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Ion Cyclotron Resonance Heating (ICRH) powers of up to 17 MW have been coupled to JET limiter plasmas. The plasma stored energy has reached 7 MJ with 13 MW of RF in 5 MA discharges with Z/sub eff/ = 2. When I/sub p//B/sub [phi]/ = 1 MA/T the stored energy can be 50% greater than the Goldston L mode scaling. This is due to transient stabilisation of sawteeth (up to 3 s) and to a significant energy content in the minority particles accelerated by RF (up to 30% of the total stored energy). Central temperatures of T/sub e/ - 11 keV and T/sub i/ = 8 keV have been reached with RF alone. (He3)D fusion experiments have given a 60 kW fusion yield (fusion rate of 2 × 1016 s/sup /minus/1/ in the form of energetic fast particles (14.7 MeV(H), 3.6 MeV(He4)) in agreement with modelling. When transposing the same calculation to a (D)T scenario, Q is predicted to be between 0.l2 and 0.8 using plasma parameters already achieved. For the first time, a peaked density profile generated by pellet injection could be reheated and sustained by ICRF for 1.2 s. Electron heat transport in the central region is reduced by a factor 2 to 3. The fusion product n/sub io/[tau]/sub E/T/sub io/ reaches 2.2 × 102° m/sup /minus/3//center dot/s/center dot/kev in 3 MA discharges which is a factor of 2.3 times larger than with normal density profile. 18 refs., 13 figs., 3 tabs.

Book Computational Analysis of Ion Cyclotron Resonance Frequency Heating for JET Experiments

Download or read book Computational Analysis of Ion Cyclotron Resonance Frequency Heating for JET Experiments written by Dani Gallart Escolà and published by . This book was released on 2020 with total page 141 pages. Available in PDF, EPUB and Kindle. Book excerpt: Heating plasmas to a relevant fusion temperature is one of the key aspects of magnetically confined fusion plasmas. Radio frequency (RF) heating with electromagnetic waves in the ion cyclotron range of frequencies (ICRF) has been proven to be an efficient auxiliary method in present fusion devices such as tokamaks. Moreover, the International Thermonuclear Experimental Reactor (ITER) will be provided with ICRF antennas as one of the main heating mechanisms. For that, the study of different heating schemes to optimise the fusion performance is of utmost importance.During the 2015-2019 Joint European Torus (JET) campaigns many efforts have been devoted to the exploration of high-performance plasma scenarios envisaged for D-T operation in JET. Experiments in D, H and T are expected to lead in 2020 to the first experiments with 50%:50% D-T mixtures. These last campaigns at JET have been focused on enhancing the fusion performance of the baseline and hybrid scenarios with the final goal of improving ITER's future operation. This thesis reports on the modelling study of plasma heating through ICRF waves and NBI for recent experiments at JET with special emphasis on plasma performance.The modelling has been performed mainly with the ICRF code PION. Simulations are in excellent agreement with experimental results which proves the reliability of the results shown in this thesis. The assessment of the results offer an overview to understand and optimise plasma performance for high-performance hybrid discharges that were performed with D plasma and H minority. Impurity accumulation control with ICRF waves was found to be efficient only for a range of central resonance locations while impurity accumulation occurred for off-axis resonance. Contribution to temperature screening from fast ions was calculated to be negligible when finite orbit widths (FOW) are taken into account, as opposed to previous studies that did not take into account FOW. Small differences in H concentration have a large impact on power partition between H and D. The lower the H concentration the larger the power channeled to D which is shown to substantially enhance the D-D fusion rate. The study of a neutron record high-performance discharge shows high bulk ion heating and low H concentration as key ingredients for increased fusion performance.Of especial relevance for ITER is the study of the D-T prediction from high-performance discharges. This analysis compares two ICRF schemes, H and 3He minority. It is shown that 3He is a strong absorber and provides higher bulk ion heating as compared to H. However, ICRF fusion enhancement is computed to be larger in H, as this scheme has a stronger 2nd harmonic heating. In D-T, ICRF fusion enhancement is computed to be significantly lower with regards to D-D plasmas due to different fusion cross sections. Results in preparation of the T and D-T campaigns at JET show that the extrapolation from T to D-T plasmas is not straightforward. PION predicts the T density to have a large impact on the T velocity distribution function for the ITER relevant 2nd$ T harmonic heating scheme. Larger concentrations of T lead to higher bulk ion heating, therefore, it is expected D-T bulk ion heating to be lower.

Book Electron Cyclotron Emission And Electron Cyclotron Resonance Heating Ec 16 Proceedings Of The 16th Joint Workshop With Cd rom

Download or read book Electron Cyclotron Emission And Electron Cyclotron Resonance Heating Ec 16 Proceedings Of The 16th Joint Workshop With Cd rom written by Ronald Prater and published by World Scientific. This book was released on 2011-02-21 with total page 427 pages. Available in PDF, EPUB and Kindle. Book excerpt: This proceedings volume, the sixteenth in a biannual series, presents a snapshot of the state of current research worldwide on Electron Cyclotron Emission (ECE) and Electron Cyclotron Resonance Heating (ECRH) and related technologies. The papers address the physics, both theory and experiment, of ECE and ECRH. The technologies of high power millimeter-wave sources — gyrotrons — and transmission lines and launchers are included. The focus is on physics and technology relevant to the research and development of nuclear fusion.

Book Computational Analysis of Ion Cyclotron Resonance Frequency Heating for DEMO

Download or read book Computational Analysis of Ion Cyclotron Resonance Frequency Heating for DEMO written by Dani Gallart Escolà and published by . This book was released on 2015 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Ion cyclotron resonance frequency heating (ICRH) is one of the most important mechanisms to heat fusion plasma. The magnetic field generated by the magnetic coils forces ions to follow a cyclotron trajectory around the magnetic field lines due to the Lorentz force. Therefore, ions revolve around the magnetic field lines in a determined frequency, the so called ion cyclotron frequency. ICRH is based on launching electromagnetic waves from the low-field side in such a way that their frequency matches the one from ions cyclotron frequency. When both frequencies match, another effect begins to occur, the wave-particle interaction. At this point, ions start damping the wave by absorbing its energy. This effect modifies the distribution function of ions which develops a tail in the high energy region. The fast ions produced by the energy absorption from the electromagnetic waves play an important role in heating the bulk plasma. Therefore, it is crucial to know how the energy of the wave is distributed among ions and electrons, and how the fast ions produced deliver their energy to the other particles, ions and electrons. This Msc thesis is a first computational assessment of bulk plasma heating for DEMO. The DEMOnstration power plant is a proposed nuclear fusion power plant that is expected to be built after the experimental reactor ITER. It will be the first fusion reactor to produce electrical energy. Its parameters and scope are still not fixed yet, a few different yet similar designs exist. However, the physical dimensions and energy output in DEMO are much bigger than that of ITER. In fact, DEMO's 2 to 4 gigawatts of fusion power will be in the scale of the modern electric power plants. In this sense, the analysis here presented, takes into account the evolution of the fast ions and assesses their behavior at DEMO. The ICRH scenarios studied are the second harmonic tritium with and without 3He in D-T plasma as they are regarded as the most promising ICRH scenarios. Plasma parameters, as temperature T and electron density ne, are scanned in order to obtain the behavior of the fast ions. A DEMO design point which has been used to perform deeper analysis for a determined case has been established at T = 30 keV , ne = 1.2 · 1020 m−3. The analysis has been carried out using the PION code. PION has been extensively benchmarked against JET results. It is able to solve the evolution in time of the distribution function and to compute the absorption of the electromagnetic wave. This problem must be solved self-consistently. PION simulations consist in a number of time steps. First of all, for each time step, the power absorbed is calculated. This information is then used for computing the distribution function with a Fokker-Planck model, which will be used to compute the absorption power at the beginning of the next time step. This process is repeated iteratively until convergence is reached. The results obtained in this work are two: i) the bulk ion heating and ii) fast ion parameters. We have noticed that by placing the resonance region slightly closer to the outer side the bulk ion heating is improved in both scenarios by reducing the direct electron damping. The values for bulk ion heating of a 100 MW electromagnetic wave launch are 55.84 MW for a plasma with 3% of 3He and 43.00 MW for a plasma without 3He. The plasma without the 3He dilution shows a higher reaction rate and also its fast ions are considerably more energetic. So, as the minority heating scenario has an enhanced bulk ion heating, the second harmonic tritium scenario presents two advantages, firstly that no 3He is required and secondly that there is no 3He dilution.

Book Ion Cyclotron Resonance Heating

Download or read book Ion Cyclotron Resonance Heating written by Ralph Ray Rudder and published by . This book was released on 1962 with total page 176 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Book Physics of Highly Ionized Atoms

Download or read book Physics of Highly Ionized Atoms written by Richard Marrus and published by Springer Science & Business Media. This book was released on 2012-12-06 with total page 474 pages. Available in PDF, EPUB and Kindle. Book excerpt: The progress in the physics of highly-ionized atoms since the last NATO sponsored ASI on this subject in 1982 has been enormous. New accelerator facilities capable of extending the range of highly-ionized ions to very high-Z have come on line or are about to be completed. We note particularly the GANIL accelerator in Caen, France, the Michigan State Superconducting Cyclotrons in East Lansing both of which are currently operating and the SIS Accelerator in Darmstadt, FRG which is scheduled to accelerate beam in late 1989. Progress i~ low-energy ion production has been equally dramatic. The Lawrence Livermore Lab EBIT device has produced neon-like gold and there has been continued improvement in ECR and EBIS sources. The scientific developments in this field have kept pace with the technical developments. New theoretical methods for evaluating relativistic and QED effects have made possible highly-precise calcula tions of energy levels in one-and two-electron ions at high-Z. The calculations are based on the MCDF method and the variational method and will be subject to rigorous experimental tests. On the experimental side, precision x-ray and UV measurements have probed the Lamb shift in the one and two electron ions up to Z=36 with increasing precision.

Book Energy Research Abstracts

Download or read book Energy Research Abstracts written by and published by . This book was released on 1990 with total page 840 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Book Multi Species Test of Ion Cyclotron Resonance Heating at High Altitudes

Download or read book Multi Species Test of Ion Cyclotron Resonance Heating at High Altitudes written by National Aeronautics and Space Administration (NASA) and published by Createspace Independent Publishing Platform. This book was released on 2018-07-07 with total page 26 pages. Available in PDF, EPUB and Kindle. Book excerpt: Observations of ion distributions and plasma waves obtained by the Dynamics Explorer 1 satellite in the high-altitude, nightside auroral zone are used to study ion energization for three ion species. A number of theoretical models have been proposed to account for the transverse heating of these ion populations. One of these, the ion cyclotron resonance heating (ICRH) mechanism, explains ion conic formation through ion cyclotron resonance with broadband electromagnetic wave turbulence in the vicinity of the characteristic ion cyclotron frequency. The cyclotron resonant heating of the ions by low- frequency electromagnetic waves is an important energy source for the transport of ions from the ionosphere to the magnetosphere. In this paper we test the applicability of the ICRH mechanism to three simultaneously heated and accelerated ion species by modelling the ion conic formation in terms of a resonant wave-particle interaction in which the ions extract energy from the portion of the broadband electromagnetic wave spectrum which includes the ion cyclotron frequency. Using a Monte Carlo technique we evaluate the ion heating produced by the electromagnetic turbulence at low frequencies and find that the wave amplitudes near the ion cyclotron frequencies are sufficient to explain the observed ion energies. Persoon, A. M. and Peterson, W. K. and Andre, M. and Chang, T. and Gurnett, D. A. and Retterer, J. M. and Crew, G. B. Unspecified Center NAGw-3576...