How does X-ray Tube Work?

X-ray tube works as follows:

1.The heated filament is positively charged and the tungsten target is negative.

2.Electrons are emitted from the heated filament towards the tungsten target due to the very high potential difference between them.

3.The tungsten target absorbs the electrons and releases some of the energy in the form of X-rays.

This process is very inefficient however and a lot of energy is released in heat. For this reason the tungsten target has a copper mounting because it conducts heat and is cooled with by circulating oil through the mount. Spinning  tungsten target at high speed also helps to stop it overheating.

What is Tungsten Target for X-ray?

Tungsten target is the anode of an x-ray tube.

As tungsten alloy have many applications, such as bulb filaments, X-ray tubes (as both the filament and target), etc.

Tungsten is used as one of the materials for the anode as the electrons emitted from the cathode and striking the anode generate a good deal of heat, besides, tungsten is a high temperature metal, which is made from raw ground tungsten powder, been pressed and sintering. It is then hot isostatic pressed, bloomed, cold rolled, machined and bonded with a copper backing plate.
The electronic structure of tungsten makes it one of the main sources for X-ray. 
For more details, you could visit tungsten target.

Why Tungsten is Chosen for X-ray Beam Protection?

Tungsten has a very high melting point but it is nevertheless melted where X-ray beam strikes: for this reason the target is rotated to give a fresh target surface very frequently and the tungsten target is a fairly thin plate welded or brazed onto a water-cooled copper backing. Less than 1% of the electrical energy delivered into the X-ray tube comes out as X-rays; the other more than 99% is waste heat. Tungsten is chosen for the short wave length and penetrating power of it's characteristic X-rays rather than because of it's high melting temperature.

For more details, you could visit tungsten target for X-ray beam.

Why Tungsten Target for X-Ray Tube is Good?

Tungsten target implies an X-ray tube where high energy electrons are directed in a vacuum to strike a tungsten target. Where the electrons strike the tungsten very short wavelength X-rays are generated and pass out through the vacuum tube for use in medical diagnosis and engineering radiography of welds and castings etc. Tungsten target is usually used in x-ray tube, there are usually two reasons for these application:

1. Tungsten has a relatively high density, which could protect relatively high energy characteristic x-rays.

2. Tungsten has the highest melting point of any metal, and because over 99% of the energy put into the x-ray tube to produce the beam is turned into heat energy, the ability to disparate the heat without loosing structural integrity is critical.

For more details, you could visit tungsten target X-ray.