A new model for simulating gyrotron oscillators in the monomode time-dependent linear self-consistent regime is presented. Starting from a nonlinear time-dependent monomode model, the linearization and the following simplification of the model, based on a moment approach, are described. This simplified model represents a numerically efficient model and allows to have a deeper physical insight, in particular, for regimes dominated by self-consistent effects such as for the gyro-backward wave instability. One specific case of a gyrotron cavity is studied in detail and compared with experimental results, with special attention to self-consistent effects and to the differences with a model using a fixed field profile. Self-consistent linear simulations are, amongst other applications, important for the design of frequency-tunable gyrotrons or high-power gyrotrons with cavities having a relatively low quality factor, but also for studies of parasitic oscillations as they may occur in beam ducts and/or in the launcher section following the interaction cavity. (C) 2014 AIP Publishing LLC.
Timothy Goodman, René Chavan, Anastasia Xydou, Matteo Vagnoni, Humberto Torreblanca Quiroz
Timothy Goodman, Stefano Alberti, Minh Quang Tran, Jean-Philippe Hogge, Damien Fasel, Matthieu Toussaint, Ugo Siravo, Jérémy Genoud, Jérémie Dubray, Jonathan Sylvain Masur, Christian Moura, Ioannis Pagonakis, Blaise Marlétaz, Konstantinos Avramidis
Stefano Alberti, Jean-Philippe Hogge, Jérémy Genoud