The greater the density of a material, the more effective it is as a shield against X-rays. And among high-density metals, lead is one of the cheapest. To give you an idea, molybdenum, which has almost the same density as lead, is 30 times more expensive. The relationship between density and the ability to block radiation is related to the cloud of electrons that revolve around the nucleus of the atom. Lead has a large cloud, which facilitates the dissipation of the energy contained in the X-ray. Insulation with lead walls is necessary because X-ray is one of the strongest forms of radiation that exist: it passes through tissues and, inside cells , causes mutations that can lead to cancer. The amount of radiation received when taking a plate is not capable of causing harm, but the person who operates the X-ray machine daily would be in serious trouble if he did not hide behind the lead wall.
– What is the difference between x-ray and body scanner?
bulk lead Despite the insulating wall, some radiation always makes it to the other side.
1. X-rays are made up of photons, the same type of particle that makes up visible light. The difference is that X-ray photons carry much more energy than light and infrared rays.
2. When an X-ray photon hits a lead wall, it dies and transfers its energy to an electron in any lead atom. With an extra charge of energy, the electron leaves its atom of origin and begins to collide with other atoms.
3. With each collision, the “connected” electron loses a little energy, which is transformed into heat – therefore, the plate heats up. After a few bumps, it loses energy – ending the radiation – and is recaptured by some lead atom.
4. But, depending on the path that the energized electron takes after contact with the X-ray, it may be able to pass through the lead wall without losing all the energy. Few electrons take this shortcut, but some always make it to the other side of the plate.