0

Let's imagine a seller scammed you and sold you a Gamma rays / X-rays "oven" instead of a common microwave oven. The power consumption would be the same as a common microwave oven, i.e. about 1 kW, but the oven would use x-rays and/or gamma rays instead of micrometric waves. How would one notice that the oven behaves differently than a common microwave oven?

I do realize that the door of the microwave ovens have holes that let pass visible light but not microwaves, so, for the sake to make the question more interesting, let's assume that the door consists of a thick metallic wall. So essentially the oven looks like a metallic box from the outside.

Would the energy be used to heat the food as much as if microwaves were used? If not, is the energy then wasted to heat the walls of the x-rays oven?

untreated_paramediensis_karnik
  • 6,250

3 Answers3

3

A microwave oven is a resonant cavity; any microwave energy that is not heating the food is reflected by the walls, and re-enters that tasty ear of corn (or whatever). X-rays, however, do not reflect, the sole way a returning bit of radiation comes from a wall is so-called secondary radiation (fluorescence).

So, the nominal 1 kW X-ray source won't deliver its full output (or anything near it) during a single pass, and the secondary radiation is both lower energy and low in efficiency (far less than half after one wall impact).

You should expect one or two orders of magnitude diminution of cooking efficiency, and much warming of the oven walls, with an X-ray source, even if it were energy-efficient and aimed to strike the food.

It will also ionize molecules in the food, which could cause flavor changes unlike those caused by simple heating.

Whit3rd
  • 10,853
1

In a past exam question, an experiment "performed by a student" described removing the rotating plate from the microwave and adding a "chocolate bar".

Due to standing waves being formed due to the EM waves reflecting off the opposite side to the transmitter, the "chocolate bar" would only "melt" in certain, periodic dots - at the antinodes.

The wavelength of the light can then be calculated by measuring the distance over $2n+1$ antinodes and then dividing this by $2n$.

We could then calculate the frequency of the EM waves being emitted, since we know $c$ and $f=\frac{c}{\lambda}$ and thus determine whether they are microwaves or x-rays.

Also, x-rays and microwaves have different properties - such as how they interact with organic matter so there is likely some simple test you could do in that sense.

Joe Iddon
  • 2,119
1

Gamma ray doses are measured in sieverts and grays: one joule per kilogram. A dose of 5 sievert is deadly, but the heat developed is negligible: a temperature rise in water of about 0.001 C.

So your kilowatt oven would be visibly ionizing the air, I think.