An electron beam passing through a metamaterial structure is predicted to generate reversed Cherenkov radiation, an unusual and potentially very useful property. We present an experimental test of this phenomenon using an intense electron beam passing through a metamaterial loaded waveguide. Power levels of up to 5 MW are observed in backward wave modes at a frequency of 2.40 GHz using a one mi...

A kinetic theory of linear electrostatic plasma waves with frequencies near the cyclotron frequency Ωcs of a given plasma species s is developed for a multispecies nonneutral plasma column with general radial density and electric field profiles. Terms in the perturbed distribution function up to O(1/Ωcs) are kept, as are the effects of finite cyclotron radius rc up to O(r 2 c ). At this order t...

Title: STOCHASTIC ELECTRON TRAJECTORIES AND WAVE INTERACTION IN RELATIVISTIC GYRO-TRAVELING-WAVE AMPLIFIERS. Roland Ngogang, Master of Science, 2005 Directed By: Professor Victor L. Granatstein, Department of Electrical Engineering Gyro-traveling-wave amplifiers (gyro-TWAs) are types of gyrodevices, which take advantage of the cyclotron maser instability to produce coherent electromagnetic (EM)...

High frequency (> 200 GHz) gyrotrons are potentially useful for several important applications, including plasma heating and radar. For electron cyclotron resonance heating of a moderate-size, high power density tokamak power reactor to ignition temperatures, a gyrotron frequency around 200 GHz appears to be necessary. The design of high frequency gyrotrons is discussed. Analysis of overall gyr...

Cyclotron modes of a non-neutral Mg ion plasma were studied in a long cylindrical PenningMalmberg trap. Several modes with angular dependence exp(iZ@, 12 1, are observed near the cyclotron frequencies of the various Mg ions. The I= 1 modes for the majority species are downshifted from the cyclotron frequencies, with downshifts as large as four times the diocotron frequency. These large shifts a...

We show that sufficiently strong laser beams with two frequencies differing by a cyclotron frequency of a free electron can give rise to strong cyclotron excitation with prohibited and allowed cyclotron orbits as well as to an optical Stark shift. This is due to a combination of relativistic effects and results in multiple isolated branches of excited motion (isolas). The formation of the first...

We predict a hysteretic three-photon cyclotron resonance in narrow-gap semiconductors driven by two laser beams with their frequency difference near the cyclotron frequency. This effect is based on the Doppler and Lorentz nonlinear mechanisms and the nonparabolicity of the conduction band. A CO(2) laser intensity of 10(5)-10(6) W/cm(2) at 10.6 and 9.4 microm is required for observation of the e...

The thermally excited axial oscillation of the electron through the weak magnetic bottle needed for the continuous Stern-Gerlach effect modulates the cyclotron frequency and produces a characteristic approximately 12-kHz-wide vertical rise-exponential decline line shape of the cyclotron resonance. At the same time the relativistic mass shift decreases the frequency by approximately 200 Hz per c...