n.a diode vacuum tube in which the flow of electrons from a central cathode to a cylindrical anode is controlled by crossed magnetic and electric fields; used mainly in microwave oscillators
N
an electronic valve with two coaxial electrodes used with an applied magnetic field to generate high-power microwave oscillations, esp for use in radar 磁电管; 有两个和实用电磁场一起产生大功率微波振动的同轴电极电子真空管
They have found that heating the sand for about 90 seconds with a microwave generator (known as a magnetron) designed for a household microwave oven produces a thermal image that is detectable for 15-20 minutes.