Generation of Rogue Waves in Gyrotrons Operating in the Regime of Developed Turbulence

Abstract

Within the framework of the average approach and direct 3D PIC (particle-in-cell) Many physical systems exhibit behavior associated with the emergence of the so-called rogue waves which represent dramatically high-amplitude events that occur with low probability but much more frequently than expected in ordinary (e.g., Gaussian or Rayleigh) wave statistics. can be suggested that, similar to lasers [5][6][7], the rogue waves can also occur in microwave oscillators representing active systems which are based on the interaction of electromagnetic waves with non-equilibrium electron beams.One of the widely studied microwave oscillators is a gyrotron in which a helical electron beam excites a waveguide mode near its cutoff frequency [10]. In this paper, we demonstrate that rogue waves can appear in gyrotrons operating in the regime of developed turbulence. It is well known that in electronic oscillators, including gyrotrons, an increase of the excess over the starting conditions leads to a complication of the radiation spectrum caused by the appearance of periodic self-modulation and then chaotic turbulent generation regimes [11][12][13][14][15][16][17]. Typically, realization of self-modulation regimes is a result of combination of a nonlinearity and delay effects [12].

Peregrine Solitons Beyond the Threefold Limit and Their Two-Soliton Interactions

“…1(e) and 1(f), with other parameters being given in the caption. This unusual peak-amplitude feature, corresponding to an intensity factor of around 225, is actually consistent with the rogue-wave anomaly recently found via a PIC (particle-in-cell) simulations in the gyrotron microwave turbulence, where the rogue waves generated could have an intensity factor of 100-150 [36].…”

“…We confirm numerically that these high-amplitude PS solutions are robust and can be excited amid the onset of MI. This finding may help shed more light on the anomalous dynamics of rogue waves in other complex multicomponent systems [36].…”

“…The latter subsequently developed into a chaotic field among which the PS structure could be singled out, as a robust pattern, therefore anticipating the possibility of experimental observation. Such an anomaly of rogue-wave creation is not an exception but a manifestation of novel physical mechanisms that take place in complex multicomponent nonlinear systems, resulting in an extreme wave event of higher amplitude [36]. We expect that our work may spark significant research interest in generation of rogue waves as well as their anomalies in birefringent fibers [44], crossing sea states [3,45], semiconductor planar waveguides [50], and even microwave turbulence [36].…”

Forecasting Events in the Complex Dynamics of a Semiconductor Laser with Optical Feedback

“…Some complex systems manifest their emergent behavior through sequences of extreme oscillations or spiking events. This type of behavior can be found in earthquake activity [4][5][6], neuronal dynamics [7,8], social networks [9], heartbeat behavior [10][11][12], optical systems [13], stock markets [12,14], among others [15][16][17].…”

Экспериментальное наблюдение хаотической генерации с шириной спектра 1.5% в гиротроне в условиях большой надкритичности

“…Однако к настоящему времени относительная ширина спектра гиротронов в подобных режимах не превышает десятых долей процента [8,9]. В то же время в [10,11] на основе динамической модели электронно-волнового взаимодействия, в которой учтена конечность времени пролета частиц через резонатор гиротрона, была продемонстрирована возможность значительного расширения полосы шумоподобного излучения в условиях, когда величина токового параметра, пропорционального току пучка и коэффициенту связи электронов с волной, существенно (на два и более порядков) превосходит стартовые значения. В настоящей работе представлены результаты первых экспериментальных исследований широкополосных режимов генерации на основе гиротрона диапазона 33 GHz, в котором достаточно большой уровень надкритичности обеспечивается за счет возбуждения низшей моды круглого волновода.…”