Generation of rogue waves in gyrotrons operating in the regime of developed turbulence

TL;DR

This paper demonstrates that gyrotrons operating in developed turbulence can sporadically produce extremely intense microwave spikes, interpreted as rogue waves, due to complex electron-wave interactions.

Contribution

It introduces a new understanding of rogue wave formation in gyrotrons through combined average and 3D PIC simulations, highlighting the role of turbulence and electron-wave interactions.

Findings

Giant spikes can be 100-150 times more intense than average power.

Generated spikes can exceed electron beam power by 6-9 times.

Spikes exhibit long-tail probability distributions characteristic of rogue waves.

Abstract

Within the framework of the average approach and direct 3D PIC (particle-in-cell) simulations we demonstrate that the gyrotrons operating in the regime of developed turbulence can sporadically emit "giant" spikes with intensities a factor of 100-150 greater than the average radiation power and a factor of 6-9 exceeding the power of the driving electron beams. Together with the statistical features such as a long-tail probability distribution, this allows the interpretation of generated spikes as microwave rogue waves. The mechanism of spikes formation is related to the simultaneous cyclotron interaction of a gyrating electron beam with forward and backward waves near the waveguide cutoff frequency as well as with the longitudinal deceleration of electrons.