Industrial Radiation Shielding Materials - What Are They Made Of?
To understand the materials used, we must first understand the basic principles of radiation shielding. Most ionizing radiation (such as X-rays and gamma rays) has extremely strong penetrating power. The most direct way to block it is to use high-density, high-atomic-number materials to "bombard" and "consume" the energy in the rays. The most common example is lead. Lead has a density of 11.34 g/cm³, an atomic number of 82, and a high electron cloud density. When radiation particles pass through, they easily collide with lead atoms, and their energy continuously decays until it is completely absorbed. This is why lead powder was added to many protective suits and walls in the past. However, lead is toxic and heavy, and now industry is starting to use elements such as tungsten, bismuth, and barium to replace it. For example, tungsten alloys have a higher density than lead and are environmentally friendly and pollution-free, gradually becoming the choice for high-end shielding materials.
Another major category of radiation in industry is electromagnetic radiation (such as electromagnetic interference and radio frequency radiation). The principle behind these materials is completely different. When facing radio frequency signals, we no longer aim to "absorb energy," but rather to create a short circuit or reflect the electromagnetic waves back. The most typical materials are highly conductive metal meshes or thin metal films, such as copper mesh, aluminum foil, and silver-plated fibers. When electromagnetic waves strike these conductive meshes, they excite electrons within the mesh to generate a reverse electromagnetic field, thereby canceling out or reflecting the original electromagnetic wave. The interior of industrial equipment is often lined with nickel-plated or copper-plated conductive cloth, or coated with conductive paint, to provide electromagnetic waves with a "fast escape" path, preventing them from interfering with internal precision circuits.
