Versatile FEM of high efficiency and high spectral purity

摘要

At Tel Aviv University we have developed and are performing research on a unique free electron maser (FEM), utilizing a traveling wave prebuncher which can operate at any frequency in the FEM's frequency band. By e-beam prebunching at or near a desired oscillator eigenfrequency we force the oscillator to operate at that particular eigenfrequency. We can select operation at an eigenfrequency leading to the highest efficiency of operation. The prebunching level and the operating eigenfrequency can be varied. With a high level of prebunching the radiated signal buildup time of the desired frequency is greatly shortened, thus, increasing considerably, the energy conversion efficiency in pulsed operation.