@article{Tran:119530, title = {Particle-in-cell (PIC) simulations of beam instabilities in gyrotrons}, author = {Tran, T. M. and Jost, G. and Appert, K. and Alberti, S. and Pedrozzi, M.}, journal = {Physics of Plasmas}, number = {8}, volume = {4}, pages = {3043-3048}, year = {1997}, abstract = {Extensive simulations are performed to investigate effects of electron cyclotron instabilities on the gyrotron beam quality, using two-dimensional axisymmetric particle-in-cell (PIG) codes. Both electrostatic and electromagnetic models, as well as realistic geometries of the gyrotron, are considered. It is found that a large beam density can lead to an electrostatic-instability-induced energy spread which substantially degrades the gyrotron efficiency. (C) 1997 American institute of Physics.}, }