Editing Resonator (section)

====Klystron====
{{main|klystron}}
The [[klystron]], tube waveguide, is a beam tube including at least two apertured cavity resonators. The beam of charged particles passes through the apertures of the resonators, often tunable wave reflection grids, in succession. A collector electrode is provided to intercept the beam after passing through the resonators. The first resonator causes bunching of the particles passing through it. The bunched particles travel in a field-free region where further bunching occurs, then the bunched particles enter the second resonator giving up their energy to excite it into oscillations. It is a [[particle accelerator]] that works in conjunction with a specifically tuned cavity by the configuration of the structures.

The [[reflex klystron]] is a klystron utilizing only a single apertured cavity resonator through which the beam of charged particles passes, first in one direction. A repeller electrode is provided to repel (or redirect) the beam after passage through the resonator back through the resonator in the other direction and in proper phase to reinforce the oscillations set up in the resonator.

[[File:Aust.-Synchrotron,-RF-Cavities-of-Linac-(Bunchers),-14.06.2007.jpg|left<!--image on left to prevent a huge block of whitespace at the end-->|thumb|RF cavities in the [[Linear particle accelerator|linac]] of the [[Australian Synchrotron]] are used to accelerate and bunch beams of [[electron]]s; the linac is the tube passing through the middle of the cavity.]]