Development of reflection gratings for advanced ECRH scenarios

An existing framework for the design of reflection gratings was reworked. It takes the astigmatic complex beam parameters and the orientations of the beam axes of the incident and reflected beams as input and synthesizes a grating, which transforms the incident beam into the reflected beam. This is done by decomposing the 3D problem into a series of 2D reflections of plane waves. The 2D grating profiles are optimized in parallel on multiple computers. Finally, the 3D grating is derived using a simplified interpolation scheme