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In order to numerically study the effects of Ion Cyclotron Resonant Heating (ICRH) on the fast particle distribution function in general plasma geometries, three codes have been coupled: VMEC[1] generates a general (2D or 3D) MHD equilibrium including full shaping and pressure anisotropy. This equilibrium is then mapped into Boozer coordinates. The full-wave code LEMan[2], [3] then calculates the power deposition and electromagnetic field strength of a wave field generated by a chosen antenna using a warm model. Finally, the single particle Hamiltonian code VENUS [4, 5] combines the outputs of the two previous codes in order to calculate the evolution of the distribution function. Within VENUS, Monte Carlo operators for Coulomb collisions of the fast particles with the background plasma have been implemented, accounting for pitch angle and energy scattering. Also, ICRH is simulated using Monte Carlo operators on the Doppler shifted resonant layer. The latter operators act in velocity space and induce a change of perpendicular and parallel velocity depending on the electric field strength and the corresponding wave vector. Eventually, the change in the distribution function will then be fed into VMEC for generating a new equilibrium and thus a self-consistent solution can be found. This model is an enhancement of previous studies in that it is able to include full 3D effects such as magnetic ripple, treat the effects of non-zero orbit width consistently and include the generation and effects of pressure anisotropy. Here, first results of coupling the three codes will be shown in 2D tokamak geometries. [ABSTRACT FROM AUTHOR]

A full-wave code for the wave propagation studies in the Alfvén and the ion-cyclotron frequency domain in 3D plasmas is presented. In addition to the cold model, a warm plasma model where kinetic effects are taken into account in the limit of small Larmor radius has also been implemented. Due to the Fourier discretization in the poloidal and the toroidal directions the parallel wave vector expression is relatively simple. However, the exact computation of k∥ in 2D and 3D configurations is complicated because of the dependence on both the spatial position and the (m,n) mode numbers considered. A comparison with the 2D PENN code is presented where we use different approximations for the value of the parallel wave vector. Parallelisation and optimisation of the cold plasma version of the LEMan code is also discussed. Due to improved matrix construction and storage algorithms, the memory requirements are considerably reduced which allows for calculations in the IC frequency range in the stellarator geometry. © 2006 American Institute of Physics [ABSTRACT FROM AUTHOR]

We present a new global solver for the Maxwell’s equations in stellarator plasmas (LEMan). The 3D geometrical effects are fully taken into account, no assumption on the wavelength is made. The full cold plasma dielectric tensor including finite electron mass is implemented, extension to the kinetic model is under development. The wave equation is discretised with finite elements (linear or cubic) radially and Fourier decomposition in the poloidal and toroidal angles. Special care is taken to correctly treat the problem near the magnetic axis. Unicity of the solution, gauge condition and the energy conservation are ensured. Some results and benchmarks for the Alfvén and ion cyclotron frequency ranges are presented. © 2005 American Institute of Physics [ABSTRACT FROM AUTHOR]