TWANG-PIC, a monomode gyro-averaged PIC code for gyrotron simulations

The new gyrotron simulation code TWANG-PIC, a Particle-In-Cell (PIC)-version of the code will be presented, which solves the slow-timescale self-consistent wave-particle interaction equations for a single transverse mode. This code represents a considerable improvement with respect to the previous trajectory-code by relaxing the approximation of a time-frozen electromagnetic (EM)-field during the electron transit across the cavity. In operating regimes dominated by self-consistent effects (gyro-backward regime) and in particular for non-stationary regimes characterized by a multifrequency spectrum, it is shown that the PIC model implemented in TWANG-PIC is in much better agreement with the experiment than the results given by TWANG.