Editing Gyrotron (section)

==Types==
The output window of the tube from which the microwave beam emerges can be in two locations. In the transverse-output gyrotron, the beam exits through a window on the side of the tube. This requires a 45° mirror at the end of the cavity to reflect the microwave beam, positioned at one side so the electron beam misses it. In the axial-output gyrotron, the beam exits through a window at the end of the tube at the far end of the cylindrical collector electrode which collects the electrons.

The original gyrotron developed in 1964 was an oscillator, but since that time gyrotron [[amplifier]]s have been developed. The helical gyrotron electron beam can amplify an applied microwave signal similarly to the way a straight electron beam amplifies in classical microwave tubes such as the klystron, so there is a series of gyrotrons that function analogously to these tubes. Their advantage is that they can operate at much higher frequencies.
The gyro-monotron (gyro-oscillator) is a single-cavity gyrotron that functions as an oscillator. A gyro-klystron is an amplifier that functions analogously to a [[klystron]] tube. Has two [[microwave cavity|microwave cavities]] along the electron beam, an input cavity upstream to which the signal to be amplified is applied and an output cavity downstream from which the output is taken. A gyro-TWT is an amplifier that functions analogously to a [[travelling wave tube]] (TWT). It has a slow wave structure similar to a TWT paralleling the beam, with the input microwave signal applied to the upstream end and the amplified output signal taken from the downstream end. A gyro-BWO is an oscillator that functions analogously to a [[backward wave oscillator]] (BWO). It generates oscillations traveling in an opposite direction to the electron beam, which is output at the upstream end of the tube. A gyro-twystron is an amplifier that functions analogously to a [[twystron]], a tube that combines a klystron and a TWT. Like a klystron, it has an input cavity at the upstream end followed by buncher cavities to bunch the electrons, which are followed by a TWT-type slow-wave structure that develops the amplified output signal. Like a TWT, it has a wide bandwidth.