Download or read book Evolution of Poloidal Variation of Impurity Density and Ambipolar Potential in Rotating Tokamak Plasma written by R. Zanino and published by . This book was released on 1988 with total page 32 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Evolution of Poloidal Variation of Impurity Density and Ambipolar Potential in Rotating Tokamak Plasma written by D. J. Sigmar and published by . This book was released on 1987 with total page 16 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Evolution of Poloidal Variation of Impurity Density and Ambipolar Potential in Rotating Tokamak Plasma written by and published by . This book was released on 1987 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: When the beam driven toroidal plasma rotation reaches thermal velocity the particle density and the ambipolar potential can develop strong poloidal variations in the flux surface. The rapid time evolution of the thermal velocity, the change in toroidal plasma rotation, and the plasma flow velocity components in the flux surface are calculated. These results are evaluated numerically using a spectral code to describe the strong poloidal couplings. Results are compared to data from the ASDEX tokamak.
Download or read book Evolution of Poloidal Variation of Impurity Density and Ambipolar Potential in Rotating Tokamak Plasma written by and published by . This book was released on 1988 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: We present numerical results of a 1-D (poloidal), time dependent code for the description of ion impurity transport on a given tokamak magnetic surface, in the presence of momentum sources such that, as observed in neutral beam injection experiments, the toroidal rotation velocities be comparable to or larger than the impurity thermal speed. We show that the densities, the velocities and the ambipolar potential reach a quasi steady state characterized by significant poloidal gradients, on a time scale of the order of the collision time, i.e. faster than the radial diffusion scale. To obtain this steady state a phenomenological drag force needs be introduced; we find that a purely classical, gyroviscous force alone is apparently insufficient to obtain a steady state, within the framework of the present model which retains only the zero-th order, in the Larmor radius expansion, ion-impurity friction.
Download or read book Evolution of Poloidal Variation of Impurity Density Andambipolar Potential in Rotating Tokamak Plasma written by C. T. Hsu and published by . This book was released on 1987 with total page 16 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 1988 with total page 968 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Energy Research Abstracts written by and published by . This book was released on 1989 with total page 624 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Energy Research Abstracts written by and published by . This book was released on 1988 with total page 880 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Poloidal Density Variation of Impurities in a Rotating Tokamak Plasma Flux Surface Coordinates and Effect on Transport Coefficients written by M. Romanelli and published by . This book was released on 1999 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book INIS Atomindex written by and published by . This book was released on 1988 with total page 902 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Government Reports Announcements Index written by and published by . This book was released on 1988-11 with total page 560 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Physics Briefs written by and published by . This book was released on 1989 with total page 1384 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Government Reports Annual Index written by and published by . This book was released on 1988 with total page 1100 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Government Reports Announcements Index written by and published by . This book was released on 1988 with total page 1132 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Experimental Tests of Parallel Impurity Transport Theory in Tokamak Plasmas written by Matthew Logan Reinke and published by . This book was released on 2012 with total page 370 pages. Available in PDF, EPUB and Kindle. Book excerpt: In realistic reactor scenarios, high temperature plasmas will be composed of not only the fusion reactants and products, but also impurities introduced purposefully or unintentionally from plasma facing materials. In tokamaks it is often assumed, sometimes erroneously, that surfaces of constant main ion pressure are also surfaces of constant impurity pressure. Although the same underlying physics determine impurity momentum balance along closed magnetic field lines, the increased mass and charge of high-Z impurities weights terms differently. Their large mass enhances inertial effects like the centrifugal force from toroidal rotation, and( can lead to accumulation of heavy impurities on the outboard side of a flux surface. Their high charge enhances ion-impurity friction and makes impurities sensitive to small poloidal variations in the electrostatic potential. In Alcator C-Mod, 2D (R,Z) measurements of photon emission from high-Z impurities reveal significant variations of impurity density on a flux surface. Poloidal variations, normalized to the flux surface average, I 2/(n ) , have been measured up to ~ 1/3, and separate cases of impurities accumulating on the inboard and outboard side of a flux surface are observed, depending on local plasmas conditions. Experiments demonstrate that these asymmetries are due to a combination of inertia., poloidal electric fields and ion-impurity friction, and measurements are compared to existing neoclassical parallel impurity transport theory. This is the first time centrifugal force has been observed to cause a substantial asymmetry in a plasma with no external momentum input and where the flow is entirely self-generated. Magnetically trapped fast ions, sustained by ion cyclotron waves, create a poloidally varying electrostatic potential which causes high-Z impurities to accumulate on the inboard side. Existing theory is extended to include this effect by incorporating a species that has an anisotropic pressure tensor. Experimental measurements in plasmas where the minority resonance layer is scanned show good qualitative and quantitative agreement with this extended theory. The sensitivity of 51/(nz) to fast-ions demonstrates the opportunity for the impurity asymmetry to be used as a novel diagnostic tool and calls into question prior work on in/out asymmetries in neutral beam heated plasmas. /down asymmetries in the banana regime are unable to be explained by ion/impurity friction in the trace limit, nZZ 2 /n
Download or read book Plasma Physics Index written by and published by . This book was released on 1982 with total page 936 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Plasma Physics Reports written by and published by . This book was released on 1993 with total page 442 pages. Available in PDF, EPUB and Kindle. Book excerpt:
