First results of a cw industrial FEM

We have designed and constructed a cw FEM system capable of operating as an oscillator or an amplifier in the X-band frequency range. This system utilises a 130 keV, 13 mA electron beam which is cw (rather than pulsed) and a 1.52 m, 38 mm period wiggler constructed from ferrite permanent magnet bars. The gain of this system as an amplifier has been measured as a function of the electron beam accelerating voltage and current level, using an external microwave source in the range 7.6–8.9 GHz, and the output power of the system as an oscillator has been measured. This paper tabulates the results and compares them to theoretical models.