Improved Simulation of Quasi-Optical Launchers for High Power Gyrotrons with Smoothing AlgorithmJianbo Jin, Gerd Gantenbein, Tomasz Rzesnicki, Manfred Thumm and John JelonnekEPJ Web Conf., 203 (2019) 04008DOI: https://doi.org/10.1051/epjconf/201920304008