Full-wave 2D modeling of helicons propagation and absorption in thespherical tokamak Globus-M2

Abstract

Numerical modeling of propagation and absorption of fast waves(helicons) with frequency 200 MHz in 2D inhomogeneous plasma of thespherical tokamak Globus-M2 was carried out with 2D full-wave code. Toroidal effects, poloidal magnetic field and the actual shape of the fluxsurfaces were taken into account. The full wave electric field and RF powerabsorption profiles were computed by solving plasma wave equation withelectron Landau damping term. The modeling demonstrated a fairly highefficiency of helicons absorption in the bulk plasma within a wide range ofexperimental parameters. The waves propagate to the inner regions of theplasma column and are mainly absorbed there; less than 20% of RF energyreturns back to the plasma periphery. Keywords: high temperature plasma, nuclear fusion, tokamak, high frequency plasma waves, helicons, plasma wave equation, full-wave code.\