Speaker
Description
See the full abstract here http://ocs.ciemat.es/EPS2019ABS/pdf/O3.402.pdf
Nonlinear synchronisation is a key process in wave-particle interaction [1], responsible for Landau damping as well as for the amplification in devices like traveling wave tubes and gyrotrons [2]. We investigate it using the finite-N approach from a self-consistent hamiltonian formalism [3]. This description is combined with a recent field decomposition [4] that allows drastic degree-of-freedom reduction while preserving conservation laws (from symplectic properties) for periodic waveguides. Those advantages enable fast time domain simulations compared to alternative particle-in-cell codes.
The model is assessed, with success, against a well-established frequency model in the linear regime [5], against nonlinear simulations [3] and against measurement from industrial TWTs [6]. Currently, our simulations handle non-sinusoidal fields (like multi-carriers). A specific formulation of this model is in preparation for helical waveguides.
Finally, we outline the occurence of the Abraham-Minkowski dilemma for waveguide amplifiers and plasmas [7]. This dilemma (well-known in dielectrics) highlights two different formulas for the momentum of light. For the wave-particle interaction, the dilemma resolution involves a non-negligible flowing momentum from Maxwell's electromagnetic stress.
References
[1] F. Doveil, Y. Elskens and D. F. G. Minenna, Wave-particle interaction studied in a traveling wave tube, 20th International Congress on Plasma Physics (ICPP 2018), Vancouver, invited (2018).
[2] A. S. Gilmour, Klystrons, Traveling Wave Tubes, Magnetrons, Crossed-Field Amplifiers, and Gyrotrons (Artech House, Boston, 2011).
[3] D. F. G. Minenna, Y. Elskens, F. André and F. Doveil, EPL, 122, 44002 (2018).
[4] F. André, P. Bernardi, N. M. Ryskin, F. Doveil and Y. Elskens, EPL, 103, 28004 (2013).
[5] D. F. G. Minenna, A. G. Terentyuk, Y. Elskens, F. André and N. M. Ryskin, Phys. Scr., in press, doi:
10.1088/1402-4896/ab060e.
[6] D. F. G. Minenna, et al., DIMOHA : Traveling-wave tube simulations including band edge and multitone
operations, 20th International Vacuum Electronics Conference (IVEC 2019), Busan, accepted (2019).
[7] D. F. G. Minenna, Y. Elskens, F. Doveil and F. André, Universality of the Abraham-Minkowski dilemma for
photon momenta beyond dielectric materials, arXiv: 1902.06431.
