Editing Cavity magnetron (section)

==Applications==
{{Missing information|section|[[Magnetron sputtering]]|date=March 2023}}

===Radar===
[[File:Magnetron radar assembly 1947.jpg|thumb|upright=1.4|9.375&nbsp;GHz 20&nbsp;kW (peak) magnetron assembly for an early commercial airport radar in 1947.  In addition to the magnetron (right), it contains a TR (transmit/receive) switch tube and the [[superheterodyne]] receiver front end, a 2K25 [[reflex klystron]] tube [[local oscillator]] and a 1N21 [[germanium diode]] mixer. The waveguide aperture (left) would be connected to a waveguide going to the antenna.]] 
{{Main|History of radar#Centimetric radar|l1=History of radar (Centimetric radar)}}

In a [[radar]] set, the magnetron's waveguide is connected to an [[antenna (electronics)|antenna]]. The magnetron is operated with very short pulses of applied voltage, resulting in a short pulse of high-power microwave energy being radiated. As in all primary radar systems, the radiation reflected from a target is analyzed to produce a radar map on a screen.

Several characteristics of the magnetron's output make radar use of the device somewhat problematic. The first of these factors is the magnetron's inherent instability in its transmitter frequency. This instability results not only in frequency shifts from one pulse to the next, but also a frequency shift within an individual transmitted pulse. The second factor is that the energy of the transmitted pulse is spread over a relatively wide frequency spectrum, which requires the receiver to have a correspondingly wide bandwidth. This wide bandwidth allows ambient electrical noise to be accepted into the receiver, thus obscuring somewhat the weak radar echoes, thereby reducing overall receiver [[signal-to-noise ratio]] and thus performance. The third factor, depending on application, is the radiation hazard caused by the use of high-power electromagnetic radiation. In some applications, for example, a [[marine radar]] mounted on a recreational vessel, a radar with a magnetron output of 2 to 4 kilowatts is often found mounted very near an area occupied by crew or passengers. In practical use these factors have been overcome, or merely accepted, and there are today thousands of magnetron aviation and marine radar units in service.  Recent advances in aviation weather-avoidance radar and in marine radar have successfully replaced the magnetron with [[Gunn diode|microwave semiconductor oscillators]], which have a narrower output frequency range.  These allow a narrower receiver bandwidth to be used, and the higher signal-to-noise ratio in turn allows a lower transmitter power, reducing exposure to EMR.

===Heating===
[[Image:Magnetron1.jpg|thumb|Magnetron from a [[microwave oven]] with magnet in its mounting box. The horizontal plates form a [[heat sink]], cooled by airflow from a fan. The magnetic field is produced by two powerful ring magnets, the lower of which is just visible. Almost all modern oven magnetrons are of similar layout and appearance.]]
In [[microwave oven]]s, the waveguide leads to a radio-frequency-transparent port into the cooking chamber. As the fixed dimensions of the chamber and its physical closeness to the magnetron would normally create standing wave patterns in the chamber, the pattern is randomized by a motorized fan-like ''[[mode stirrer]]'' in the waveguide (more often in commercial ovens), or by a turntable that rotates the food (most common in consumer ovens).
An early example of this application was when British scientists in 1954 used a microwave oven to resurrect [[Cryogenics|cryogenically]] frozen [[hamsters]].<ref>{{Cite journal|last1=Smith|first1=A. U.|last2=Lovelock|first2=J. E.|last3=Parkes|first3=A. S.|date=June 1954|title=Resuscitation of Hamsters after Supercooling or Partial Crystallization at Body Temperatures Below 0°C.|url=https://doi.org/10.1038/1731136a0|journal=Nature|volume=173|issue=4415|pages=1136–37|doi=10.1038/1731136a0|pmid=13165726|bibcode=1954Natur.173.1136S|s2cid=4242031|issn=0028-0836}}</ref>

===Lighting===
In microwave-excited lighting systems, such as a [[sulfur lamp]], a magnetron provides the microwave field that is passed through a [[waveguide]] to the lighting cavity containing the light-emitting substance (e.g., [[sulfur]], [[metal halide]]s, etc.).  Although efficient, these lamps are much more complex than other methods of lighting and therefore not commonly used.
More modern variants use [[HEMT]]s or GaN-on-SiC [[power semiconductor device]]s instead of magnetrons to generate the microwaves, which are substantially less complex and can be adjusted to maximize light output using a [[PID controller]].