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It seems like it should due to bremsstrahlung, since we're talking about electrons with 5-7KeV of energy slamming into the walls of the device, but I've found no information about this online, so I'm assuming something else must be happening. CRT-style TVs and computer monitors both have this problem, so my guess is that most of the energy is being bled out of the electrons to form microwaves. Am I right?

Also, what happens to the production of microwaves as the magnets on the magnetron slowly lose strength?

Thanks

Joel
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2 Answers2

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Just a google search for "magnetron x-rays" yields quite a bit of information. From this data sheet:

High voltage magnetrons emit a significant intensity of X-rays not only from the cathode sidearm but also from the output waveguide. These rays can constitute a health hazard unless adequate shielding for X-ray radiation is provided. This is a characteristic of all magnetrons and the X-rays emitted correspond to a voltage much higher than that of the anode.

A quick further glance seems to show that the penetration depth for x-rays into most materials at 7keV is dismal.

lionelbrits
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NASA Armstrong avionics tech here - RF specialist. The old medical studies on RF state a safe voltage level would be below 5,000 volts for the transmitter. Above that, the possibility of parasitic X-rays increases with voltage, especially in radar equipment. From what I understand so far, microwave oven magnetrons typically need about 4,000 volts from their transformer to oscillate, so it is within the safe range.

Anthony Dean
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