Wave chaos and the temperature dependence of LHCD efficiency
Weakly damped lower-hybrid wave propagation is shown to be chaotic for parameter regimes typical of current drive in Tore Supra and JT-60. In these cases, the spectral gap is filled by wave energy that diffuses to higher k(parallel) in the stochastic layer. Agreement between theoretical and experimental scalings for the current drive efficiency is obtained by including non-resonant losses of wave energy, due to collisions and lossy reflections near the plasma edge, which reduce the efficiency at low temperatures, when the spectral gap is large.
Bibliographic Reference: Report: EUR-CEA-FC-1460 EN (1992) 17 pp.
Availability: Available from CEA, Département de Recherches sur la Fusion Contrôlée, Saint-Paul-lez-Durance (FR)
Record Number: 199211212 / Last updated on: 1994-11-29
Original language: en
Available languages: en