The reflex gyrotron

A typical problem of low-power short-wavelength gyrotrons is that a too long cavity is required to provide the start of rf oscillations. Therefore, it is attractive to realize a gyrotron with a long enough operating region but relatively low diffraction Q-factor of the operating cavity. In this work, we propose a gyrotron with reflecting of electrons back to the operating cavity. Such a scheme provides significant decrease of the starting current and considerable efficiency enhancement. (C) 2012 American Institute of Physics. [doi:10.1063/1.3684237]