What Is X-ray Emission?

X-rays are produced in an evacuated X-ray tube, which has a source of electrons (a heated filament) and a tungsten target. A potential difference of nearly 50,000 to 100,000 V is maintained between the filament and the target. Due to the high potential difference, electrons are accelerated towards the tungsten target and strike it with very high speeds.

The atoms of tungsten are excited and then emit X-rays in the process of de-excitation. The X-rays produced in this way have fixed frequencies and are known as characteristic X-rays. X-rays with a continuous range of frequencies, known as continuous X-rays, are produced when some electrons are decelerated in the vicinity of target nuclei.