Simulation of gyrotrons using the high-order particle-in-cell code PICLasS. M. Copplestone, P. Ortwein, C.-D. Munz, K. A. Avramidis and J. JelonnekEPJ Web Conf., 149 (2017) 04019DOI: https://doi.org/10.1051/epjconf/201714904019