TITLE
	Chaotic Electron Dynamics In Gyrotron Resonators
	
AUTHOR
	Kyriakos HIZANIDIS and Yannis KOMINIS

ABSTRACT 
	Phase space analysis of electron dynamics is used in combination with the canonical 
	perturbation method and the KAM theory in order to study the dependence of the efficient 
	gyrotron operation on the RF field profile and frequency mismatch. An extension of the 
	KAM theory to Hamiltonian systems with aperiodic perturbations is used and approximate 
	analytical invariants of the motion are constructed by utilizing the canonical 
	perturbation theory. Comparisons between numerical and analytical results show that these 
	invariants contain the essential features of the complex and inhomogeneous phase space 
	structure of the system. Moreover, gyrotron efficiency is directly connected to the 
	destruction of specific KAM surfaces under strong enough perturbation and appropriate RF 
	field profile, which result in electrons which can lose energy and provide gain for the 
	field, depending chaotically on their initial conditions (phase). Also, accurate estimates 
	of the spectrum of the electron rest energies, provided by the aforementioned analysis, are 
	useful for the efficient operation of a depressed collector.