Alpha-particle Effects on High-toroidal Mode Number Instabilities in Tokamaks PDF Download
Are you looking for read ebook online? Search for your book and save it on your Kindle device, PC, phones or tablets. Download Alpha-particle Effects on High-toroidal Mode Number Instabilities in Tokamaks PDF full book. Access full book title Alpha-particle Effects on High-toroidal Mode Number Instabilities in Tokamaks by G. Rewoldt. Download full books in PDF and EPUB format.
Author: G. Rewoldt
Publisher:
ISBN:
Category :
Languages : en
Pages : 37
Get Book Here
Book Description
Author: G. Rewoldt
Publisher:
ISBN:
Category :
Languages : en
Pages : 37
Get Book Here
Book Description
Author:
Publisher:
ISBN:
Category :
Languages : en
Pages :
Get Book Here
Book Description
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.
Author: G. Rewoldt
Publisher:
ISBN:
Category :
Languages : en
Pages : 18
Get Book Here
Book Description
Author:
Publisher:
ISBN:
Category :
Languages : en
Pages : 28
Get Book Here
Book Description
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.
Author:
Publisher:
ISBN:
Category :
Languages : en
Pages : 22
Get Book Here
Book Description
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.
Author: C.Z. Cheng
Publisher:
ISBN:
Category : Alpha rays
Languages : en
Pages : 36
Get Book Here
Book Description
Author: D. J. Sigmar
Publisher:
ISBN:
Category :
Languages : en
Pages : 62
Get Book Here
Book Description
Author:
Publisher:
ISBN:
Category :
Languages : en
Pages :
Get Book Here
Book Description
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.,
Author: Mietek Lisak
Publisher:
ISBN:
Category :
Languages : en
Pages : 32
Get Book Here
Book Description
Author:
Publisher:
ISBN:
Category : Controlled fusion
Languages : en
Pages : 170
Get Book Here
Book Description
