Improved Simulation of Quasi-Optical Launchers for High Power Gyrotrons with Smoothing Algorithm Jianbo Jin, Gerd Gantenbein, Tomasz Rzesnicki, Manfred Thumm and John Jelonnek EPJ Web Conf., 203 (2019) 04008 Published online: 25 March 2019 DOI: 10.1051/epjconf/201920304008