- A heated cathode produces electrons
- These electrons are accelerated by a high voltage towards a metal target
- Upon collision, these electrons are decelerated and hence emit EMR in the form of x-rays
AKA braking radiation or bremsstrahlung
Bremsstrahlung is the continuous spectrum of x-rays emitted, due to electrons travelling at different velocities or not transferring all of their energy into the photons.
- If electrons have sufficient energy, they may be able to knock out electrons from an inner shell.
- Then, outer shell electrons will drop down into the vacancy, emitting an x-ray with an unusually high intensity.
- These are called characteristic x-rays, symbol = K
- Kα peaks are caused by a transition between E2 to E1
- Kβ are caused by a transition between E3 to E1
- Hence, photons produced by Kβ have more energy, as it has more energy levels to drop down.
Here is a short animation explaining the process.