A Ka- band gyrotron oscillator powered by a 600 kV pulse-line accelerator has produced approximately 100 MW at 35 GHz in a circular TE62 mode. It has also demonstrated frequency tuning over the range 28 to 49 GHz by operating in a family of TEm2 modes, with the azimuthal index m ranging from 4 to 10, by variation of the guide magnetic field. Operation is in general agreement with the predictions of theory.
The design of a 10-20-MW 40-ns cyclotron auto-resonance maser (CARM) is presented. The basic components of CARM are a pulseline accelerator, magnetic-field coils, a novel 600-kV 2 0 0 4 field-emission electron gun designed for p L / p z = 0.6 and A p z / p z < 3 percent, and a "whispering-gallery" mode rippled-wall cavity, designed for a high Q for the desired CARM mode and low Q for competing gyrotron modes. The NRL CARM operates with a wave group velocity that is less than optimum for autoresonance, but where the cyclotron maser instability is strong. By keeping the interaction region short (less than 10 cyclotron orbits), the effect of velocity spread is reduced, and the efficiency can be quite high; computer simulations indicate that the device will operate at efficiencies greater than 20 perstrength requirement is substantially reduced. The CARM can provide millimeter and submillimeter radiation in the first electi-on-cyclotron harmonic using currently available magnet technology. For example, the experiment at the is designed to produce powers in excess Of 10 MW at 100 GHz with a 600-kV beam and a magnetic field of only 25 kG, while a firstharmonic gyrotron at 100 G H~ with the Same beam voltage requires a magnetic field of over 70 kG.
FEL, the CARM can reach submillimeter wavelengthsResearch with a magnetostatic-wiggler cent.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.