Wave kinetic description of lower-hybrid absorption in tokamaks
The wave kinetic equation (WKE) describes the propagation and absorption of short wavelength modes and can be an effective method to treat multi-pass absorption and wave chaos, which is important in lower-hybrid current drive. In the WKE, action density (or energy density in a stationary medium) is convected along ray trajectories in the (k,x) phase space, where k is the wave vector and x the position vector. The cylindrical tokamak model, for which the exact wave equation is separable was considered first. For a mode launched at the plasma edge (with given poloidal and toroidal mode numbers), solutions of the WKE give the radial profile of the energy density and absorbed power. These were found to be in good agreement with numerical solutions obtained from a full wave code. In toroidal geometry, however, the poloidal number is not conserved and stochastic layers develop in ray phase space.
Bibliographic Reference: Paper presented: 1993 International Sherwood Fusion Theory Conference, Newport, Rhode Island (US), March 28-31, 1993
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Record Number: 199310618 / Last updated on: 1994-11-29
Original language: en
Available languages: en