Abstract of REFMUL3 Project

Simulation of reflectometry using a Finite-difference Time-domain (FDTD) code is one the most popular numerical techniques used, as it offers a comprehensive description of the plasma phenomena. This method requires however, to keep error to a minimum, a fine spatial grid discretization, which also implies a high-resolution time discretization to comply with CFL stability condition. As a consequence, simulations in 3D are now prohibitive in computational time. This is particularly true if with full-size requirements to simulate large devices as JET or ASDEX Upgrade or next generation machines like ITER. Memory demands become also constringent. The only way to circumvent these issues is to develop a parallel 3D code. REFMUL3, a 3D code being developed at Instituto de Plasmas e Fusão Nuclear (IPFN), is a full- wave code using a FDTD Yee scheme [1] with full polarization able to cope simultaneous with o- and x-mode and supports a general external magnetic field and a dynamic plasma. It will be able to cope with a wider range of scenarios than the present day codes can (which are 2D, either o- or x-mode). REFMUL3 is in an early stage of development. Since such a code has forcibly to be parallel, it makes sense to act at an early stage to enforce a structure compatible to the parallelization needs. Moreover, the solutions developed during the HLST-REFMULXP (2013) and HLST- REFMUL2P (2014) projects will be of great value in REFMUL3. The 3D code is a highly envisaged code that is much needed in the EU fusion programme and a major new tool for the reflectometry community.