American Nuclear Society
Home

Home / Publications / Journals / Fusion Science and Technology / Volume 47 / Number 1T

Confinement Asymmetry and Trapped Particle Effects on Radial Transport in Charged Plasmas

A. A. Kabantsev, C. F. Driscoll

Fusion Science and Technology / Volume 47 / Number 1T / January 2005 / Pages 263-266

Technical Paper / Open Magnetic Systems for Plasma Confinement

Weak axial variations in B(z) or (z) in "axisymmetric" plasma traps cause a fraction of the particles to be trapped axially, with a velocity-space separatrix between trapped and passing populations. The trapped and passing particles experience different dynamics in response to a variety of -asymmetries in the E × B rotating plasma, so a discontinuity in the velocity-space distribution f(v) tends to form at the separatrix. Collisional scatterings thus cause large fluxes as they smooth the distribution in a boundary layer near the separatrix. In essence, this separatrix dissipation damps the AC or DC longitudinal currents induced by plasma waves or confinement field asymmetries. This trapped-particlemediated damping and "neoclassical" particle transport often dominates in cylindrical pure electron plasmas, and may be important in other nominally symmetric open systems.

 
Questions or comments about the site? Contact the ANS Webmaster.
advertisement