X-rays created by fission stage of a hydrogen bomb?

[naita]

@scr4

You’re thinking of Cherenkov radiation. Bremsstrahlung is just radiation from charged particles that are accelerated, e.g. when a high energy electron is deflected as it nears an atomic nucleus.

d’oh! :smack:

So the electrons do most (all) of it, because they accelerate more?

[KidCharlemagne]

@Chronos

All sorts of distributions of energy are possible, only one of which is thermal. Most other distributions don’t have names, but one that does is a monochromatic source, in which all of the photons have the same energy (at least, approximately). Another one commonly encountered is a line source, which is basically a mix of a small number of monochromatic sources.

You can have thermal radiation anywhere in the spectrum. It’s just that, after some point, the temperatures become impractical for many purposes. A thermal X-ray source will have a temperature of a million degrees or so; a thermal microwave source will only be a few degrees above absolute zero. But both exist (and in fact the most perfect thermal spectrum we’ve ever observed is in the microwave range-- the Cosmic Microwave Background Radiation).

So what is an example of a non-thermal x-ray source?

[DPRK]

SILAC

[scr4]

@KidCharlemagne

So what is an example of a non-thermal x-ray source?

X-ray tube. Most medical X-ray & CT machines have some type of X-ray tube.

Synchrotron.

Characteristic X-ray.

Radioactive isotopes. (Though technically that’s a type of characteristic X-ray emission. When a nucleus decays, the electrons readjust to the orbits of the new element, and the excess energy can be emitted as a characteristic X-ray.)

[scr4]

@naita

So the electrons do most (all) of it, because they accelerate more?

Yes. They are moving faster to begin with, and when they collide with ions, they are deflected (accelerated) by a larger amount because they are much lighter than ions. Even a bare proton is 2000x heavier than an electron.

[KidCharlemagne]

@scr4

X-ray tube. Most medical X-ray & CT machines have some type of X-ray tube.

Synchrotron.

Characteristic X-ray.

Radioactive isotopes. (Though technically that’s a type of characteristic X-ray emission. When a nucleus decays, the electrons readjust to the orbits of the new element, and the excess energy can be emitted as a characteristic X-ray.)

Thanks, that helps. Would x-rays created from a Coolidge tube be considered thermal, whereas those created by a Crooke’s tube would not?

[scr4]

@KidCharlemagne

Thanks, that helps. Would x-rays created from a Coolidge tube be considered thermal, whereas those created by a Crooke’s tube would not?

They both use electric fields to accelerate the electrons towards the target, so they are both non-thermal.

What matters is the energy distribution of electrons hitting the target. If you just had a hot filament next to a target, with no electrical field, then that would be thermal emission. Except you’d have to heat the filament to several million degrees to generate fast enough electrons to generate X-rays.