Download or read book Alpha particle Effects on High toroidal Mode Number Instabilities in Tokamaks written by G. Rewoldt and published by . This book was released on 1988 with total page 37 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Alpha particle Effects on High n Instabilities in Tokamaks written by and published by . This book was released on 1988 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Hot .cap alpha.-particles and thermalized helium ash particles in tokamaks can have significant effects on high toroidal mode number instabilities such as the trapped-electron drift mode and the kinetically calculated magnetohydrodynamic ballooning mode. In particular, the effects can be stabilizing, destabilizing, or negligible, depending on the parameters involved. In high-temperature tokamaks capable of producing significant numbers of hot .cap alpha.-particles, the predominant interaction of the mode with the .cap alpha.-particles is through resonances of various sorts. In turn, the modes can cause significant anomalous transport of the .cap alpha.-particles and the helium ash. Here, results of comprehensive linear eigenfrequency-eigenfunction calculations are presented for relevant realistic cases to show these effects. 24 refs., 12 figs., 6 tabs.

Download or read book Beam ion and Alpha particle Effects on Microinstabilities in Tokamaks written by G. Rewoldt and published by . This book was released on 1982 with total page 18 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Comparison of High n Instabilities Including Alpha particle Effects in BPX and TFTR written by and published by . This book was released on 1991 with total page 28 pages. Available in PDF, EPUB and Kindle. Book excerpt: Three distinct types of high toroidal mode number instabilities are obtained from a comprehensive kinetic calculation, using as input transport code results from the analysis of a recent design for the Burning Plasma Experiment (BPX). These instabilities are: the collisionless trapped-electron ion-temperature-gradient mode, the magnetohydrodynamic ballooning mode, and a high toroidal mode number version of the toroidicity-induced Alfven eigenmode or gap'' mode. The dependence of the instability linear eigenfrequencies on minor radius, beta, and toroidal mode number are investigated, along with the effects of hot alpha particles. Relative quasilinear fluxes of particles and energy for each species are also obtained. In addition, the beta dependence of the magnetohydrodynamic ballooning mode is investigated for a case using as input the results of a transport code calculation for the Tokamak Fusion Test Reactor (TFTR) in an extrapolation to a deuterium-tritium mixture. The effects of alpha particles and the relative quasilinear fluxes are also investigated for this case. 13 refs., 13 figs., 4 tabs.

Download or read book Destabilization of Tokamak Pressure gradient Driven Instabilities by Energetic Alpha Populations written by and published by . This book was released on 1989 with total page 22 pages. Available in PDF, EPUB and Kindle. Book excerpt: Alpha particle populations can significantly alter existing MHD in stabilities in tokamaks through kinetic effects and coupling to otherwise stable shear Alfven waves. Here we consider resonances of the trapped alpha precessional drift with both the usual ballooning mode diamagnetic frequency ([omega]{sub *i}/2) and the toroidicity induced Alfven eigenmode (TAE). This is examined for noncircular tokamaks in the high-n ballooning limit using an isotropic alpha slowing down distribution and retaining the full energy and pitch angle dispersion in the alpha drift frequency. Applying this to CIT and ITER indicates that ballooning instabilities can persist at [Beta]'s below the ideal MHD threshold. These are especially dominated by the destabilization of the TAE mode. In addition, a hybrid fluid-particle approach for simulating alpha effects on pressure-gradient driven instabilities is described. 13 refs., 6 figs.

Download or read book Excitation of High n Toroidicity induced Shear Alfven Eigenmodes by Energetic Particles and Fusion Alpha Particles in Tokamaks written by C.Z. Cheng and published by . This book was released on 1992 with total page 36 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Alpha Particle Effects in Burning Tokamak Plasmas written by D. J. Sigmar and published by . This book was released on 1986 with total page 62 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Alpha Storage Regime in High Temperature Sub ignited D T Tokamaks written by and published by . This book was released on 1988 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Alpha particle parameters in sub-ignited D-T tokamaks like TFTR can be optimized in a high temperature ''alpha storage regime '' in which the alpha particle thermalization time [tau]/sub .cap alpha./ is long (approx. 1.0 sec) and in which the alpha particle source rate S/sub .cap alpha./ is enhanced due to a beam-target and beam-beam reactions (by a factor of approx. 2-3). Near reactor-level alpha instability parameters .beta./sub .cap alpha./(0) approx. n/sub .cap alpha./(0)/n/sub e/(O) approx. 1% are predicted by simulation codes when Q approx. 0.5-1, while present TFTR ''supershots'' already have .beta./sub .cap alpha./(O) approx. n/sub [alpha](O)/n/sub e/(O) /approx/ 0.1-0.2%. Plasmas in this regime can be used to test theories of collective alpha instabilities for the first time, and can be used to provide a strong (but transient) alpha heating pulse. An experimental scenario to exploit this regime is described. 28 refs., 5 figs., 5 tabs.,

Download or read book Excitation of Thermonuclear Cone Instabilities by Toroidal Equilibrium Distributions of High energy Alpha Particles in Tokamaks written by Mietek Lisak and published by . This book was released on 1989 with total page 32 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Fusion Energy Update written by and published by . This book was released on 1982-04 with total page 170 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book On Resonant Excitations of High n Magnetohydrodynamic Modes by Energetic alpha Particles in Tokamaks written by and published by . This book was released on 1989 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Analytical theories for the excitations in tokamaks of magnetohydrodynamic (MHD) modes with large toroidal mode numbers (n”1) are presented. Specifically, only instability mechanisms due to resonances with energetic ions/alpha particles are considered. It is noted that, while trapped energetic particles contribute to the ideal region, circulating energetic particles contribute mainly to the singular layer dynamics. A unified dispersion relation manifesting both fishbone-like modes and beam transit-resonance modes is then driven. Finally, we also analyze the stability property of toroidicity-induced shear Alfven waves excited via transit resonances with alpha particles in ignited tokamaks. 11 refs.

Download or read book Energy Research Abstracts written by and published by . This book was released on 1994 with total page 806 pages. Available in PDF, EPUB and Kindle. Book excerpt: Semiannual, with semiannual and annual indexes. References to all scientific and technical literature coming from DOE, its laboratories, energy centers, and contractors. Includes all works deriving from DOE, other related government-sponsored information, and foreign nonnuclear information. Arranged under 39 categories, e.g., Biomedical sciences, basic studies; Biomedical sciences, applied studies; Health and safety; and Fusion energy. Entry gives bibliographical information and abstract. Corporate, author, subject, report number indexes.

Download or read book Nuclear Science Abstracts written by and published by . This book was released on 1976-02 with total page 722 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Scientific and Technical Aerospace Reports written by and published by . This book was released on 1992 with total page 1572 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book ERDA Energy Research Abstracts written by United States. Energy Research and Development Administration and published by . This book was released on 1976 with total page 1320 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Alpha Particle Destabilization of the Toroidicity induced Alfven Eigenmodes written by C. Z. Cheng and published by . This book was released on 1990 with total page 28 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book ERDA Energy Research Abstracts written by United States. Energy Research and Development Administration. Technical Information Center and published by . This book was released on 1977 with total page 1682 pages. Available in PDF, EPUB and Kindle. Book excerpt: