Penetrating radiation protection materials include radiation protection concrete, heavy metal materials such as lead and steel, ordinary concrete, clay brick masonry, compacted soil, graphite, radiation protection glass, radiation protection rubber and plastic, etc.
Surface radiation protection materials include organic plates, coatings, metallic materials and inorganic nonmetallic materials. Of course, radiation protection materials can also be classified according to their chemical composition, such as metal materials, inorganic non-metal materials, polymer materials and organic-inorganic composite materials.
Lead is the most commonly used radiation protection material with high density and hardness, which can effectively block most radiation. Lead-boron polyethylene (Pb-B polyethylene) and lead-boron polyethylene (Pb-B polyethylene) are new substitute materials, which combine the characteristics of lead and boron and have excellent protective effect.
Lead-boron polyethylene has good corrosion resistance, high temperature resistance and fire resistance, and has a long service life without affecting radiation protection performance. Lead can absorb X-rays and gamma rays, reducing the penetration of radiation.
Basic requirements of radiation protection materials
Almost all materials have certain protective ability against X-rays and γ-rays. The greater the density of a substance, the stronger the protection against X-rays and γ-rays. Therefore, if low-density lightweight materials are used, the structural thickness required to achieve the same protective effect will be large, thus reducing the effective use area of the building.
Of course, the extensive sources of materials, the difficulty of construction and the economic rationality should be considered in specific projects. For the protection of neutron rays, not only heavy elements but also enough light elements are needed.
Because for high-energy fast neutrons, there is a deceleration effect in high-density matter; For medium-speed neutrons with low energy, only substances containing hydrogen can slow them down, and hydrogen is rich in water, so substances containing crystal water or chemically bound water can be used as "chemical guards" to protect neutron flow.
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