Wetenschapsforum

Hallo

hoe worden eigenlijk microgolven opgewekt? Op wikipedia heb ik het volgende gevonden:

"All cavity magnetrons consist of a hot cathode with a high (continuous or pulsed) negative potential by a high-voltage, direct-current power supply. The [url=http:///wiki/Cathode]cathode[/url] is built into the center of an evacuated, lobed, circular chamber. A magnetic field parallel to the filament is imposed by a permanent magnet. The magnetic field causes the electrons, attracted to the (relatively) positive outer part of the chamber, to spiral outward in a circular path rather than moving directly to this [url=http:///wiki/Anode]anode[/url]. Spaced around the rim of the chamber are cylindrical cavities. The cavities are open along their length and connect the common cavity space. As electrons sweep past these openings, they induce a resonant, high-frequency radio field in the cavity, which in turn causes the electrons to bunch into groups."

Het merendeel van deze uitleg begrijp ik, alleen het laatste stukje is mij niet heel duidelijk:

"As electrons sweep past these openings, they induce a resonant, high-frequency radio field in the cavity,"

Kan iemand dit laatste toelichten? Dank bij voorbaat.

Magnetron