Kinetic Theory of Toroidicity-induced Alfven Eigenmode

Download or read book Kinetic Theory of Toroidicity-induced Alfven Eigenmode written by and published by . This book was released on 1992 with total page 29 pages. Available in PDF, EPUB and Kindle. Book excerpt: An analytic kinetic description of the toroidicity-induced Alfven eigenmode (TAE) is presented. The theory includes electron parallel dynamics non-perturbatively, an effect which is found to strongly influence the character and damping of the TAE -- contrary to previous theoretical predictions. We use a parallel conductivity model that includes collisionless (Landau) damping on the passing electrons and collisional damping on both trapped and passing electrons. Together, these mechanisms damp the TAE more strongly than previously expected. This is because the TAE couples (or merges) with the kinetic Alfven wave (KAW) if the gap is sufficiently thin and/or the magnitude of the conductivity is sufficiently small. The high damping could be relevant to recent experimental measurements of the TAE damping coefficient. In addition, the theory predicts a kinetic'' TAE, whose eigenfrequency lies just above the gap, whose existence depends on finite conductivity, and which is formed by the coupling of two KAWs.