Finite Larmor radius wave equations in tokamak plasmas in the ion cyclotron frequency range
The constitutive relation of a non-homogeneous plasma for high frequency (h.f.) waves in the ion cyclotron frequency domain is derived by integrating the Vlasov equation along the unperturbed particle orbits in the drift approximation. The integro-differential wave equations and the corresponding power balance equation in tokamak geometry are obtained by expanding the h.f. current to second order in the ratio of the ion Larmor radius to the typical perpendicular wavelength: terms proportional to the much smaller ratio of Larmor radius to the length characterising equilibrium gradients are neglected. This allows the casting of the FLR wave equations into an explicit vector form and the clear identification of the physical meaning of each term. The complete set of FLR wave equations is compared with a considerably simpler set previously derived by Swanson, Colestock and Kashuba. The conclusion reached is that at least in the important scenario of a hydrogen minority in a deuterium plasma (and of pure first harmonic heating as a particular case), use of the reduced set of equations is well justified, provided that finite Larmor radius contributions to electron absorption are taken into account.
Bibliographic Reference: Article: Plasma Physics and Controlled Fusion, Vol. 31 (1989) No. 5, pp. 723-757
Record Number: 199010585 / Last updated on: 1994-12-01
Original language: en
Available languages: en